BobLewiston's Feed - Programmer's Heaven

best anti-malware software?

Mon, 15 Feb 2010 20:05:27 -0700

Posted a 'new message on the Off topic board forum.

What's the best software to prevent malware infections? The best to detect infections? The best to eradicate them? The best single all-in-one product?

rootkit.gen - swerftx.sys infection

Sat, 13 Feb 2010 13:14:56 -0700

Posted a 'new message on the Off topic board forum.

I'm infected with rootkit.gen (specifically: swerftx.sys, unique code IQ1LCWD7) at LBA sector 0 of my MBR. It's a "highly severe" Trojan which can enable a remote computer to take over my computer, among other things. I don't want to pay Webroot $100 to remove it for me. How do I remove it myself, or where can I learn how to do so? Or is there too much to learn just to save myself $100, or does it require special software that isn't available to the average person? Should I use ComboFix? (I've got it, but I've heard it can be dangerous.) Help!

recommend good online courses for SQL, data controls?

Wed, 12 Aug 2009 15:05:15 -0700

Posted a 'new message on the C# forum.

Can anybody recommend good online courses for SQL and/or data controls? (I guess I should master the regular data controls before going on to Silverlight, right?)

suggestions for first moderately ambitious application?

Wed, 12 Aug 2009 14:50:36 -0700

Posted a 'new message on the C# forum.

Hi, everybody. I've been studying C# (using Visual C# 2008 Express) for several months and I think I've got the basics down pretty well at this point, so now I want to create a moderately ambitious application to consolidate and grow my skills. Any suggestions for what kind of app would utilize the full set of skills that would be expected from a preprofessional level student?

creating threads in C#

Fri, 17 Jul 2009 11:28:41 -0700

Posted a 'new message on the C# forum.

Can someone please break down a simple statement for a relative newbie?

Thread firstThread = new Thread (new ThreadStart (Method1));

In other words, what is happening at each stage here:

new ThreadStart (Method1)

new Thread (new ThreadStart (Method1))

Thread firstThread = new Thread (new ThreadStart (Method1));

Thanks for any help you can give.

help with BindingSources

Sun, 05 Apr 2009 10:46:30 -0700

Posted a 'new message on the C# forum.

I need some help with BindingSources (in C#).

This is what I'm working on:

From the C# tutorial at Programmer's Heaven (http://www.programmersheaven.com/2/Les_CSharp_13_p9):

private void btnLoadData_Click(object sender, System.EventArgs e)
{
string connectionString = "server=P-III; database=programmersheaven; uid=sa; pwd=;";
SqlConnection conn = new SqlConnection (connectionString);
string cmdString = "SELECT * FROM article";
SqlDataAdapter dataAdapter = new SqlDataAdapter (cmdString, conn);
DataSet ds = new DataSet ();
dataAdapter.Fill (ds, "article");
dgDetails.SetDataBinding (ds, "article");
}

When I try to compile this, I get the following error: "The name 'dgDetails' does not exist in the current context".

I have just been told that dgDetails is a BindingSource. I'm a newbie, so I'm not familiar with BindingSources.

Could you tell me what I need to include in my code to get the compiler to recognize the dgDetails BindingSource and compile my app?

dataAdapter.Update / SQL PasswordHash NULL problem

Sun, 29 Mar 2009 21:01:56 -0700

Posted a 'new message on the SQL-Server forum.

I’m learning SQL. I’m accessing database SQL2008 AdventureWorks, table Person.Contact, which has a column PasswordHash, of type varchar (128). Here’s the code I’m using to save records:

// here dataTable and dataSet have been declared at the class-wide level as
// private DataTable dataTable;
// private DataSet dataSet;

DataRow row = dataTable.Rows [currRec];

row.BeginEdit ();
row ["Title"]        = txtTitle.Text;
row ["FirstName"]    = txtFirstName.Text;
row ["MiddleName"]   = txtMiddleName.Text;
row ["LastName"]     = txtLastName.Text;
row ["Suffix"]       = txtSuffix.Text;
row ["Phone"]        = txtPhone.Text;
row ["EmailAddress"] = txtEmailAddress.Text;
row.EndEdit ();

try { dataAdapter.Update (dataSet, "Person.Contact"); }
catch (System.Runtime.InteropServices.ExternalException exc)
{
    MessageBox.Show (exc.Message + "\n\n" + currRec + "\n\"" + 
        dataSet.Tables ["Person.Contact"].Rows [currRec] ["PasswordHash"].ToString () + "\"", 
        "System.Runtime.InteropServices.ExternalException");
}
catch (Exception exc) { MessageBox.Show (exc.Message, "Exception"); }
            
try { dataSet.AcceptChanges (); }
catch (Exception exc) { MessageBox.Show (exc.Message, "dataSet.AcceptChanges ();"); }

When I edit and save an existing record (which already has a PasswordHash) to the locally resident DataSet and then to the database, it works fine (which of course means that the AdventureWorks sample database is not read-only). But when I try to save a new (inserted) record, even if I include a statement

row ["PasswordHash"] = "GylyRwiKnyNPKbC1r4FSqA5YN9shIgsNik5ADyqStZc=";

in the above Edit, I get the following System.Runtime.InteropServices.ExternalException message:

Cannot insert the value NULL into column 'PasswordHash', table 'AdventureWorks.Person.Contact'; column does not allow nulls.
INSERT fails.
The statement has been terminated.

I get this message despite the fact that the PasswordHash is displayed in the MessageBox as being in the Dataset, and the statement

dataSet.AcceptChanges ();

throws no exception!

Using SQL Server 2008 Management Studio Express, I can find no property of column PasswordHash that would account for this.

Can anybody tell me: how can I write to the PasswordHash column? (This is the most important question in this post, and what distinquishes it from my previous thread.)

Next question (for when I have the above issue resolved): although "GylyRwiKnyNPKbC1r4FSqA5YN9shIgsNik5ADyqStZc=" is a real password hash that I lifted from an already existing record (see above), I’m pretty sure I can’t just plunk it into a new record, because I notice that every record has a different password hash, which means every record has a different password. This seems very strange to me. What purpose could this serve? And more importantly: how can I generate valid password hashes for new records that have not (yet) had passwords associated with them?

Or perhaps I can make SQL Server Management Studio allow NULL in the PasswordHash column. I discovered this would be possible in SQL Server Management Studio via:

expand table | expand Columns | right-click PasswordHash column | click Modify | in lower right frame: toggle Allow Nulls from No to Yes

On doing so and then attempting to exit SQL Server Management Studio, I got a dialog box saying:

Save changes to the following items?
SQL Server Objects
<Server name>.AdventureWorks - Person.Contact

Clicking Yes elicited the following message:

Saving changes is not permitted. The changes you have made require the following tables to be dropped and re-created. You have either made changes to a table that can't be re-created or enabled the option Prevent saving changes that require the table to be re-created.

Contact (Person)

SQL Server Management Studio's onboard Help says I can override the "Prevent saving changes that require the table to be re-created" setting via:

Tools | Options | Designers | Table and Database Designers | Prevent saving changes that require table re-creation

I can try this, but I wonder if it might be dangerous, under two possible scenarios:

Firstly, if for whatever reason the table can't be re-created, could I possibly destroy the original table in the process and then have to reinstall the AdventureWorks database? I don't want to have to do that, since for some unknown reason I had a very difficult time installing it the first time.

And secondly, I have received the following warning about allowing null password hashes:

These tables are usually related to one another. There are referential and domain integrity checks within the tables across the database. Although you might be able to change some of these, some of the relationships and checks might be broken because of your update.

In other words, the writer speculates that allowing null password hashes might compromise the relationships between tables. For that matter, I suppose the same might be said about using “fake” password hashes, as described above.

On the other hand, wouldn't a password hash be relevant only to applications that use passwords? All I want MY application to do is to edit, insert and delete records. It won't require any passwords. Is it really likely that relationships between tables could be compromised if null or “fake” password hashes are used?

For what it's worth, I'm working in a 32-bit environment with the following software:

SQL Server 2008 Express with Advanced Services
database: SQL2008 AdventureWorks (schema.table: Person.Contact)
SQL Server 2008 Management Studio Express
Visual C# 2008 Express

how to copy entire Visual C# solution?

Sat, 14 Mar 2009 21:44:53 -0700

Posted a 'new message on the C# forum.

Is there any way to copy an entire Visual C# solution in such a way that it works? If you just copy it and rename it, it gives an error message that it's been renamed and therefore it refuses to work.

How to uninstall AdventureWorks sample databases?

Sat, 14 Mar 2009 19:37:43 -0700

Posted a 'new message on the SQL-Server forum.

How can I uninstall the AdventureWorks sample databases? They're not an application, so I can't do it via Add / Remove Programs or a downloaded uninstaller.

They're apparently corrupt, and they've been trouble from the git-go. The machine crashed when installing them. When I try to access them via SQL Server Management Studio, the machine crashes. When I try to reinstall them without uninstalling them, the machine crashes.

The setup prgram is SQL2008.AdventureWorks_All_Databases.x86.msi (yes, my machine is 32-bit) which I downloaded from http://msftdbprodsamples.codeplex.com/Release/ProjectReleases.aspx?ReleaseId=18407, which a couple other folks have told me worked fine for them. And my installer is up to date, and the only system requirement (a correct version of Windows) has been met.

I don't want to guess which files I should delete manually - that could be inviting trouble.

In summary: help!

How to import ".mdb" files into SQL Server 2008?

Thu, 12 Mar 2009 21:58:07 -0700

Posted a 'new message on the SQL-Server forum.

Assuming it can be done (as I've been told):

How do I import ".mdb" (MS Access / OleDb) files (specifically, Northwind sample database files) into SQL Server 2008 (Express with Advanced Features)?

Can SQL Server 2008 access Northwind or Pubs databases?

Thu, 12 Mar 2009 17:05:49 -0700

Posted a 'new message on the SQL-Server forum.

I've installed SQL Server 2008 Express with Advanced Features, but I've been having so-far insurmountable problems installing the AdventureWorks sample databases. However, I've successfully installed the Northwind sample databases, and I've downloaded the installer for the Pubs sample databases, so:

Can SQL Server 2008 access Northwind or Pubs databases?

AdventureWorks mayhem

Wed, 11 Mar 2009 13:24:05 -0700

Posted a 'new message on the SQL-Server forum.

After some initial problems with the prerequisite installation of SQL Server Express with Advanced Features, I tried to install AdventureWorks sample databases.

Upon launch of the installer, Windows cited Microsoft as AdventureWorks' publisher.

I confirmed to the installer that it should run. A dialog box then came up saying something to the effect of "Please wait while we check for disk usage." The system slowed considerably. This went on for a long, long time before I terminated the installer.

I tried again. This time a dialog box came up saying "Please wait while the Setup Wizard installs MS SQL Server 2008 AdventureWorks Databases Refresh 1 Samples (x86)". A progress bar appeared which soon maxed out. Then nothing happened. The system was greatly slowed. I couldn't terminate the installer.

I tried to bring up the Task Manager via Ctrl-Alt-Del, but it refused to appear. The system was completely frozen, except the mouse could still move its pointer. Since no other way would work, I had to hold the power button in for ten seconds to turn off the machine so I could reboot.

Whuh'd'ya make of this?

Pub sample database

Tue, 10 Mar 2009 16:14:22 -0700

Posted a 'new message on the SQL-Server forum.

I heard of a sample database called Pub. Does anyone know about it? Is it an SQL Server sample database that, unlike AdventureWorks, doesn't require SQL Server's Full-text Search capability to install? That's what I need.

Re: I can’t install SQL Server 2008 Enterprise

Mon, 09 Mar 2009 22:16:47 -0700

Posted a 'reply on the SQL-Server forum.

I tried SQL Server 2008 Enterprise 180-day evaluation version - same result.

Windows XP Pro is a 32-bit op sys, right?

Mon, 09 Mar 2009 20:27:26 -0700

Posted a 'new message on the Windows XP forum.

Windows XP Pro is a 32-bit op sys, right?

I can’t install SQL Server 2008 Express with Advanced Services - Help!

Mon, 09 Mar 2009 16:29:19 -0700

Posted a 'new message on the SQL-Server forum.

I installed SQL Server 2008 Express, basic edition (SQLEXPR32_x86_ENU_Bootstrapper.exe, version 9.0.30729.1) without any problem.

Then I attempted to install AdventureWorks Sample Databases for SQL Server 2008 (SQL2008.AdventureWorks_All_Databases.x86.msi). This attempt failed because SQL Server 2008 Express, basic edition doesn’t support Full-text Search, which AdventureWorks requires.

So I uninstalled SQL Server 2008 Express, basic edition and attempted to install SQL Server 2008 Express with Advanced Services (SQLEXPRADV_x86_ENU.exe,version 10.00.1600.22), which does support Full-text Search. This attempt failed because the installer demands an account number and password, which I don’t have.

Bear in mind, all Express versions of SQL Server are free from Microsoft, and I obtained my copy directly from Microsoft (http://www.microsoft.com/express/sql/download).

Moreover, although during the course of the installation a Product Key window appears, in which a user might have under different circumstances be intended to enter a registration key, in this version of the software this is clearly not intended. I say this because not only is the radio button labeled “Specify a free edition” selected (with the associated drop-down menu showing “Express with Advanced Services”), and the other associated radio button labeled “Enter the product key” is left unselected, but also this entire group of WinForm controls is rendered inactive.

Incidentally, I also tried to add Full-text Search capability to my original installation of SQL Server 2008 Express, basic edition via it’s Configuration Manager, but the Manager showed (wrongly) that this capability was already installed and was unable to implement this capability.

So: what do I do now?

how to obtain SQL Server FullText Search service?

Sun, 08 Mar 2009 09:41:44 -0700

Posted a 'new message on the SQL-Server forum.

I did a full installation of SQL Server 2008 Express. Looking at Add / Remove Programs, I see the following pertinent programs installed:
SQL Server 2008
SQL Server 2008 Browser
SQL Server 2008 Management Objects
SQL Server 2008 Native Client
SQL Server 2008 Setup Support File (English)
SQL Server Compact 3.5 SP1 Design Tools English
SQL Server Compact 3.5 English
SQL Server Database Publishing Wizard 1.3
SQL Server VSS Writer
SQL Server System CLR Types

And of course I also have installed .Net Framework 3.5 SP1.

I'm now trying to obtain sample SQL databases. To this end, and by the advice of others, I'm trying to install SQL2008.AdventureWorks_All_Databases.x86.msi. But whether I try to install "Sample Files" or "Create AdventureWorks DBs", I keep getting the following error:

PrepInstance() failed for MSSQL$SQLEXPRESS.
The following features are missing: Full Text Search

Running services.msc shows the following local services (but not SQL Server FullText Search):
SQL Active Directory Helper Service
SQL Server (SQLEXPRESS)
SQL Server Agent (SQLEXPRESS)
SQL Server Browser
SQL Server VSS Writer

Does anyone know how I can obtain the FullText Search service for SQL Server 2008 Express?

SQL2008.AdventureWorks install problem

Sat, 07 Mar 2009 14:50:49 -0700

Posted a 'new message on the SQL-Server forum.

I'm trying to install SQL2008.AdventureWorks_All_Databases.x86.msi, but whether I try to install "Sample Files" or "Create AdventureWorks DBs", I keep getting the following error:

PrepInstance() failed for MSSQL$SQLEXPRESS.
The following features are missing: Full Text Search

I already have installed on my PC:
Microsoft SQL Server 2008
Microsoft SQL Server 2008 Browser
Microsoft SQL Server 2008 Management Objects
Microsoft SQL Server 2008 Native Client
Microsoft SQL Server 2008 Setup Support File (English)
Microsoft SQL Server Compact 3.5 SP1 Design Tools English
Microsoft SQL Server Compact 3.5 English
Microsoft SQL Server Database Publishing Wizard 1.3
Microsoft SQL Server VSS Writer

Any suggestions?

Re: PROGRAMMERSHEAVEN.MDB

Sat, 07 Mar 2009 13:50:36 -0700

Posted a 'reply on the C# & VB.NET School Support forum.

Yes, I'll second that. Where can I download programmersheaven.mdb?

Any other SQL or Access / OleDb databases available?

Sat, 07 Mar 2009 11:27:23 -0700

Posted a 'new message on the Access forum.

I'm working through the lessons at Programmer’s Heaven's "C# School" tutorial (http://www.programmersheaven.com/2/Les_CSharp_0), and I'm currently on lesson 13, "Data Access in .Net using ADO.Net", so of course I've been trying to connect to Programmer’s Heaven's SQL and MS Access / OleDb databases. Unfortunately, they're now offline. Can anyone please tell me; are there other such databases available for those learning ADO to practice connecting to?

Any other SQL or MS Access / OleDb databases available?

Sat, 07 Mar 2009 11:26:17 -0700

Posted a 'new message on the SQL-Server forum.

Any other SQL or MS Access / OleDb databases available?

Sat, 07 Mar 2009 11:21:41 -0700

Posted a 'new message on the Database & SQL forum.

Any other SQL or OLE databases available?

Sat, 07 Mar 2009 10:36:37 -0700

Posted a 'new message on the C# & VB.NET School Support forum.

I'm working through the lessons at Programmer’s Heaven's "C# School", and I'm currently on lesson 13, "Data Access in .Net using ADO.Net", so of course I've been trying to connect to Programmer’s Heaven's SQL and MS Access / OleDb databases. Unfortunately, they're now offline. Can anyone please tell me, are there other such databases available for those learning ADO to practice connecting to?

Any other SQL or OLE databases available?

Sat, 07 Mar 2009 09:59:25 -0700

Posted a 'new message on the C# forum.

Sorry, this should have been posted in the C# School forum. I'm reposting it there. I would delete it from this forum if I was able to.

Re: how to change WinForm controls' text color programatically?

Thu, 05 Mar 2009 13:18:46 -0700

Posted a 'reply on the .NET General forum.

Oaklandstyle:

In VC# Express 2008, the problem is that you can only change a TextBox's ForeColor if you also change it's BackColor.

how to signal WinForm control input out of range?

Thu, 05 Mar 2009 13:12:03 -0700

Posted a 'new message on the .NET General forum.

Is there a way (perhaps via EventArgs) to signal the app when a user tries to enter out-of-range input into a WinForm control? (Specifically, a number in a NumericUpDown control numericUpDown1 that is larger than numericUpDown1.Maximum?) Yes, I know the control won't allow the input, but I want to display an error message if this happens.

how to change WinForm controls' text color programatically?

Wed, 04 Mar 2009 16:15:54 -0700

Posted a 'new message on the .NET General forum.

Can anybody tell me how to change WinForm controls' text color programatically? I have no problem finding the fields to assign colors to, but the compiler doesn't recognize any color I mention, whether it's something like WindowText, or something like Red.

BTW, I'm using VC# Express 2008.

Programmers Heaven's databases still available?

Wed, 04 Mar 2009 15:54:57 -0700

Posted a 'new message on the C# forum.

I'm working through the lessons at C# School, and I'm currently on lesson 13, "Data Access in .Net using ADO.Net", so of course I'm trying to connect to Programmers Heaven's databases, so far without success. Can anyone please tell me, are these databases still available?

easy way to format numbers to strings?

Mon, 02 Mar 2009 10:34:17 -0700

Posted a 'new message on the C# forum.

In C#, I'd like to convert some numbers to strings in a standard format, but preferably in a simple way, such as if you were going to output them rather than store them in string variables, a la:

Console.WriteLine ("{0:F2}", num);

rather than use a bunch of string methods to make them all the same number of significant digits. Isn't there any way to do this?

Why use delegates?

Thu, 26 Feb 2009 16:37:28 -0700

Posted a 'new message on the .NET General forum.

Why use delegates?

I understand HOW to use delegates, but in what situations would you actually use them? The examples I see in the literature are all in situations where the code could just be written without ever using them.

Is my understanding of code generation in WinForm apps correct?

Thu, 26 Feb 2009 16:14:16 -0700

Posted a 'new message on the .NET General forum.

Is my understanding of code generation in WinForm apps correct?

When you create a program that features a single Windows Form using Visual C#'s Windows Form Designer, three source files are created:

1. program.cs, which:
.....a. does some preliminary configuration of the form and then launches it, and <-- couldn't configuration be done transparently upon launching?
.....b. all the user-written, non-form-related stuff.

2. form1.cs, whose generated code contains that part of the form's class that is to be editted by the user, including "empty" methods:
.....a. the constructor, which calls InitializeComponent, which initializes the form, and
.....b. various user-written, event-driven methods, which:
..........1. handle "operation" of the form, and
..........2. call Application.Exit, which terminates execution of the form.

3. form1.designer.cs, whose generated code contains that part of the form's class that is NOT to be editted by the user:
.....a. the Windows Form Designer generated method InitializeComponent, and
.....b. the method Dispose, which disposes of the form. <-- can't this be editted?

problems compiling first Windows application

Wed, 11 Feb 2009 18:06:55 -0700

Posted a 'new message on the .NET General forum.

I tried to compile a Windows Forms Application in Visual C# 2008 Express with this source code from the CSharpSchool tutorial at Programmer's Heaven:

using System;
using System.Windows.Forms;
using System.Drawing;
namespace CSharpSchool
{
    class HelloWinForm
    {
        static void Main ()
        {
            Application.Run (new MyWindow ());
        }
    }
    class MyWindow : Form
    {
        public MyWindow () : base ()
        {
            this.Text = "My First Windows Application";
            this.Size = new Size (300, 300);
            Label lblGreeting = new Label ();
            lblGreeting.Text = "Hello WinForm";
            lblGreeting.Location = new Point (100, 100);
            this.Controls.Add (lblGreeting);
        }
    }
}

but I got these errors:

Error 1 Program 'C:\Documents and Settings\Bob\Local Settings\Application Data\Temporary Projects\HelloWinForm\obj\Release\HelloWinForm.exe' has more than one entry point defined: 'HelloWinForm.Test.Main()'. Compile with /main to specify the type that contains the entry point. C:\Documents and Settings\Bob\Local Settings\Application Data\Temporary Projects\HelloWinForm\Form1.cs 8 21 HelloWinForm

Error 2 Program 'C:\Documents and Settings\Bob\Local Settings\Application Data\Temporary Projects\HelloWinForm\obj\Release\HelloWinForm.exe' has more than one entry point defined: 'HelloWinForm.Program.Main()'. Compile with /main to specify the type that contains the entry point. C:\Documents and Settings\Bob\Local Settings\Application Data\Temporary Projects\HelloWinForm\Program.cs 14 21 HelloWinForm

Error 3 'HelloWinForm.Form1.Dispose(bool)': no suitable method found to override C:\Documents and Settings\Bob\Local Settings\Application Data\Temporary Projects\HelloWinForm\Form1.Designer.cs 14 33 HelloWinForm

Feeding this into a search engine:

"visual c#" "Compile with /main"

yielded this link:

Compiler Error CS0017
Visual C# Reference: Errors and Warnings. Compiler Error CS0017 ... Compile with /main to specify the type that contains the entry point. ...
msdn.microsoft.com/en-us/library/t9k01y87.aspx

which said:

If you are using MS Visual Studio and do not want to delete the other Main() methods you can specify the class which you want as you Entry Point in Startup Object in the Project Properties under Application Tab (at least for VS2008 Express)

Going to:

Project | HelloWinForm Properties | Application | Startup Object

I discovered it wasn't set. Setting it to either HelloWinForm.Test or HelloWinForm.Program, the first two problems disappear, but not the third. I can't see how this code has more than one entry point, and I'm not at all clear on why the compiler requires these gyrations in Startup Object. None of these issues are mentioned by CSharpSchool, which claims the code I used will run as written. This is my first Windows app, and WOW! am I in the dark on this. What gives? Maybe I should just get a different tutorial. Any explanations of this or, failing that, any suggestions for which tutorial(s) I should use?

throwing exceptions

Tue, 03 Feb 2009 15:20:05 -0700

Posted a 'new message on the .NET General forum.

The documentation I've found is a little hazy on this subject, so it's time to fire off yet another no-doubt ignorant question:

Is "throw" intended exclusively for the following scenario: Control is transferred out of a try block via a method call, and code in the called method then detects an exception, so the called method uses "throw" to transfer control back to the appropriate catch block associated with the original try block?

delegates and references to objects

Mon, 02 Feb 2009 19:20:36 -0700

Posted a 'new message on the C# forum.

The concept of delegates (references to methods) per se is new to me (although I used function pointers in C years ago), and although the literature acknowledges that there are significant differences between delegates and the use of pointers to objects, I'm nonetheless a little confused by how similar the syntax used for references to methods is to that used for references to objects.

Recently at a few different forums I posted a brief outline of my understanding of the instantiation of objects, and got corroboration and helpful feedback from several developers. Let me very briefly summarize my current understanding, for comparison to the way delegates work:

Steps to create and prepare to use an object:

1 Define a class: create a "blueprint" for objects of this class.

2 Declare an object: create a reference variable to hold a reference (address) of an object. The reference variable must be of the same class as the object.

3 Instantiate an object: allocate space for the object in the heap.

4 Assign an object to an object reference variable: place an object's address in an object reference variable.

Syntax used to implement these steps (numerals refer to the steps given immediately above):

1 Define a class:

class <class name> { < whatever > }

2 Declare an object:

<class name> <object name>;

3 Instantiate an object:

new <class name> ();

This is usually done within the same statement as assigning the object to an object reference variable (see immediately below), unless the object's reference (address) is being returned to some calling method.

3 & 4 Instantiate an object and assign it to an object variable within a single statement:

<object name> = new <class name> ();

2, 3 & 4 Declare an object, instantiate it and assign it to an object variable within a single statement:

<class name> <object name> = new <class name> ();

This seems very similar to how I understand delegates to work, which I've summarized below.

Steps to create and prepare to use a delegate reference:

1 Define a delegate type: specify the signature (including return type) of methods that delegates of this type can point to. This is called "declaring" the delegate; which I think is kind of confusing, since "declaring an object" means to create a reference variable to hold the reference (address) of an object (see step #2 above for objects), but in my opinion "declaring" the delegate is really much more analogous to defining a class (see step #1 above for objects).

2 Declare a delegate reference variable: create a delegate reference variable to hold the reference (address) of some methods. The delegate reference variable must be of the delegate type with the same method signature as the methods it will point to.

3 Instantiate a delegate: allocate space for a delegate in the heap. [BTW, what actually goes in the heap here - the reference (address) of a method, or a copy of the method?]

4 Assign the delegate to a delegate reference variable: place a method's address in a delegate reference variable.

Syntax used to implement these steps (numerals refer to the steps given immediately above):

1 "Declare" a delegate:

delegate <return type> <delegate identifier> (<parameter list>);

2 Declare a delegate reference variable:

<delegate identifier> <delegate name>;

3 Instantiate a delegate:

new <delegate identifier> (<method name>);

3 & 4 Instantiate a delegate and assign it to a delegate reference variable within a single statement:

<delegate name> = new <delegate identifier> (<method name>);

2, 3 & 4 Declare a delegate, instantiate it and assign it to a delegate reference variable within a single statement:

<delegate identifier> <delegate name> = new <delegate identifier> (<method name>);

Any feedback on my thoughts would be appreciated.

overriding VC# formatting defaults

Sun, 01 Feb 2009 15:04:09 -0700

Posted a 'new message on the C# forum.

Is there any way in Visual C# 2008 Express to override the formatting defaults? For instance, I want a single space before open parens when I'm passing arguments, but VC# won't let me do that.

identifying file types

Wed, 28 Jan 2009 16:47:31 -0700

Posted a 'new message on the C# forum.

Within a C# program, is there any way to tell if a file is a text file or not? I mean a real way, not just basing your conclusion on a file name extension.

using .Net Reflector

Sun, 25 Jan 2009 17:06:36 -0700

Posted a 'new message on the .NET General forum.

Please forgive what is surely a stupid question:

How do I use .Net Reflector to find out which namespace a class, method or property is in, or to see parameter lists? There's no way to enter a character string to tell it what you're looking for.

instantiation; and arrays & structures really objects?

Wed, 21 Jan 2009 15:03:40 -0700

Posted a 'new message on the C# forum.

Pardon me for flogging a dead horse here, but I'm trying to understand as clearly as possible some issues pertaining to the instantiation of objects.

Firstly, have I correctly analyzed the functions and uses of each of the various syntaxes related to instantiating objects? Please don't flame me, saying "why don't I read the documentation". I've read it thoroughly. The point is I want to understand the material in finer detail than for which I can find documentation.

To declare an object [create an object variable to hold a reference ("handle") of an object of the required class type]:

ClassName ObjectName;

(Am I not correct that a handle is simply an address?)

To instantiate an object (allocate space for it in the heap):

new ClassName ();

When an object is instantiated, it is usually within the same statement "assigned" to an object variable (see immediately below). This "assignment" means the reference of the object is placed into the object variable to make the variable "point to" the object. However, this reference may instead be returned to a calling method without assigning it to an object variable.

To instantiate an object and assign it to an object variable within a single statement:

ObjectName = new ClassName ();

To declare an object (variable), instantiate an object and assign the object to the object variable within a single statement:

ClassName ObjectName = new ClassName ();

To assign the reference of an object held by one object variable to another object variable (to make both object variables point to the same object):

ObjectName2 = ObjectName;

Secondly, what is the precise relationship of arrays and structures to classes and objects?

Objects are instantiations of classes, and as such are reference-type variables, space for which is allocated in the heap, not on the stack.

struct is said to be a "lightweight" form of class, and structures, like objects, must be instantiated. But structures can be instantiated without use of the keyword "new" (unlike classes), which means that no constructor is executed when structures are instantiated in this way.

Also, structures are of value-type, and so space for them must be allocated on the stack, not in the heap. Plus, like all value types, structures lack inheritance functionality.

So are structures objects or not?

I have read that arrays ARE objects. They also can be instantiated without use of the keyword "new", but only if they are also initialized (and sized) within the same statement:

DataType [] ArrayName = { < element list > };

In this case, it must be that, as with structures, no constructor is executed.

In addition, although the individual elements of an array may be of a user-defined data type, an array itself is never an instantiation of a user-defined data type (I think). Furthermore, like structures, arrays lack inheritance functionality.

So are arrays really objects? They seem so different from other objects.

And just as a matter of curiosity:

Arrays are inherited from the System.Array class. But ALL data types in C#, even value types including implicit types, are implicitly inherited from the System.Object class. (Of course, that doesn't mean all variables, regardless of data type, are objects.)

So is the System.Array class inherited directly from the System.Object class? (For that matter, is there any way I can actually read the namespace files?)

finding text files in C# console applications

Sun, 18 Jan 2009 12:45:28 -0700

Posted a 'new message on the C# forum.

In C# console applications, isn't there a simpler way than handling exceptions to just find out if a text file of a given name exists in the current directory? I'm talking about something along the same lines as the following methods:

create text file:

StreamWriter SW = File.CreateText ("MyFile.txt");

open existing text file:

StreamReader SR = File.OpenText ("MyFile.txt");

append to text file:

StreamWriter SW  = File.AppendText ("MyFile.txt");

the "this" reference & indexers

Thu, 15 Jan 2009 14:58:44 -0700

Posted a 'new message on the C# forum.

Can anybody give me a hint about how to put these two techniques together? I can use the "this" reference to control access to the private fields of an individual object:

using System;
namespace MyNamespace
{
class Program
{
static void Main ()
{
Citizen citizen = new Citizen ();

citizen.Name = "Larry Fine";
citizen.Age = 89;

Console.WriteLine ("{0}, {1}\n\n\n", citizen.Name, citizen.Age);
}
}

class Citizen
{
private string name;
private int age;

public string Name
{
get { return name; }
set { name = value; }
}

public int Age
{
get { return age; }
set { age = value; }
}
}
}

And I can use indexers to make an array of objects:

using System;
namespace MyNamespace
{
class Program
{
static void Main ()
{
Citizen citizen = new Citizen ();

citizen [0] = "Larry Fine";
citizen [1] = "Buster Douglas";
citizen [2] = "Mortimer Snerd";
citizen [3] = "Horace Greeley";
citizen [4] = "Ornette Coleman";

Console.WriteLine ("{0}\n{1}\n{2}\n{3}\n{4}\n", citizen [0],
citizen [1], citizen [2], citizen [3], citizen [4]);
}
}

class Citizen
{
private string [] name = new string [5];

public string this [int i]
{
get { return name [i]; }
set { name[i] = value; }
}
}
}

But I can't figure out how to put the two techniques together to control access to the private fields of an array of objects. The solution is probably staring me right in the face, but I don't see it. Any help?

P.S. This is a console application, obviously.

P.P.S. BTW, what happened to all my indentation?

the "this" reference & indexers

Thu, 15 Jan 2009 14:58:42 -0700

Posted a 'new message on the C# forum.

C# console applications & highlighting output to screen

Fri, 09 Jan 2009 17:11:15 -0700

Posted a 'new message on the C# forum.

In a C# console application, can anyone tell me how to "highlight" certain characters, that is, print them brighter than other characters?

C#, kbhit & getch

Thu, 08 Jan 2009 18:12:07 -0700

Posted a 'new message on the C# forum.

In C#, what methods take the place of the old kbhit and getch functions in C? (I'm writing a console application in Visual Studio.)