VB.NET Forum RSS Feed (Replies Included)

Re: need help!!

Fri, 20 Nov 2009 08:03:30 -0700

Thanks Sean for all your help.. I have tried the suggestion you gave me but they don't seem to work. I'm using vb.net express 2008 and mysql server 5.1. However when i use .selectedIndex or .SelectedText, the app doesnt crash...but fails to insert.
Besides intellisense does not give me the .SelectedItem.value option.

By the way have you ever worked with winwedge???
Thanks for all your time.

Re: need help!!

Thu, 19 Nov 2009 12:00:36 -0700

Sorry for my delay in responding...

It seems to me that your problem isn't a SQL error, but instead a syntax error.

.SelectedItem is an Object (in this case, a DataViewRow, because it is bound from a datatable). You cannot convert a DataViewRow into a string value... What you need to use is .SelectedValue or .SelectedItem.Value

So change the sql= line to this:

sql = "insert into invoice(transactionid, description, quantity, weight, agent, airline, destination, price,time) values('" & TextBox1.Text & "', '" & TextBox2.Text & "', '" & TextBox3.Text & "', '" & TextBox4.Text & "', '" & ComboBox1.SelectedItem.Value & "', '" & ComboBox2.SelectedItem.Value & "', '" & ComboBox3.SelectedItem.Value & "', '" & TextBox5.Text & "', NOW());"

Re: Two Dimensional Arrays in VB.NET

Wed, 18 Nov 2009 11:05:45 -0700

Thanks for the Thanks Ruth.

Surprisingly, we don't get a lot of thank yous in here :)

You bring up a good point, I have been teaching a student how to program and there isn't a lot of information out there for the complete-noob... most assumes you have some programming knowledge already.
I was thinking about putting my information up as free tutorials on my website in the near future. This is encouraging ;)

-Sean C

Re: Two Dimensional Arrays in VB.NET

Wed, 18 Nov 2009 10:39:36 -0700

Bless you guys... this is the clearest I have seen this concept explained & I have been looking everywhere... I am trying to teach myself VB.Net & arrays have really been giving me fits... I suspect I will need to be comfortable with them before I start trying to learn the database end of the deal, so I have really been putting lots of time in playing with arrays & trying to understand the 'why' behind each part of the process.

Ruth

Re: need help!!

Wed, 18 Nov 2009 01:14:44 -0700

hey seancampbell this is my code...
ON form load event..
Dim conn As New MySqlConnection
conn.ConnectionString = "server=localhost;" _
& "database=cargomanager;" _
& "userid=root;" _
& "password=admin;"
Try
conn.Open()
Catch myerror As MySqlException
MsgBox("failed to connect to database")
End Try
sql0 = "select name as cname from agent"
sql1 = "select name as dname from airline"
sql2 = "select abbreviation as ename from destination"
command.Connection = conn
command.CommandText = sql0
command1.Connection = conn
command1.CommandText = sql1
command2.Connection = conn
command2.CommandText = sql2
adapter.SelectCommand = command
myadapter.SelectCommand = command1
myadapter2.SelectCommand = command2
adapter.Fill(dt)
myadapter.Fill(dt1)
myadapter2.Fill(dt2)
ComboBox1.DataSource = dt
ComboBox1.DisplayMember = "cname"
ComboBox2.DataSource = dt1
ComboBox2.DisplayMember = "dname"
ComboBox3.DataSource = dt2
ComboBox3.DisplayMember = "ename"
conn.Close()
conn.Dispose()
This is the insert statement on button click event..
Try
sql = "insert into invoice(transactionid, description, quantity, weight, agent, airline, destination, price,time) values('" & TextBox1.Text & "', '" & TextBox2.Text & "', '" & TextBox3.Text & "', '" & TextBox4.Text & "', '" & ComboBox1.SelectedItem & "', '" & ComboBox2.Selecteditem & "', '" & ComboBox3.Selecteditem & "', '" & TextBox5.Text & "', NOW());"
command.Connection = conn
command.CommandText = sql
command.ExecuteNonQuery()
MsgBox("operation successfull")
Catch myerror As MySqlException
MsgBox("operation failed")
End Try
this is the error msg
Operator '&' is not defined for string "insert into invoice(transactioni" and type 'DataRowView'.

hamming code

Tue, 17 Nov 2009 20:19:58 -0700

has any1 ever tried to program the hamming code in vb.net? and are u willing to share !?

Re: need help!!

Tue, 17 Nov 2009 10:31:52 -0700

Have you looked at the contents of the Insert Statement to see why it is giving you an insert error? It'd be very helpful, for me to give you a good answer, if you provided the exact error messages and some sample code...

Here is a suggestion on something to try so you can understand why your statement is crashing:

MsgBox(ComboBox1.SelectedItem.GetType.ToString, vbOkOnly, "Test")

You'll see that you get a type like "ListItem" or something from ComboBox1.SelectedItem. That is because ComboBox1.SelectedItem returns an OBJECT, not a VALUE, and that OBJECT is determined by the Datasource of the ComboBox (in this case you have added an item manually with ComboBox.Items.Add, so it uses a default data type and adds it to the datasource).....

So here is some things you can use:

ComboBox1.SelectedText 'this should work
ComboBox1.SelectedValue 'this works when you have a datasource and a valuemember set
ComboBox1.Items(ComboBox1.SelectedItem).Text

Here is an example of how to check if something is selected, and get the value:

'Assume ComboBox1 is the name of your combobox control
Dim ComboVal as STring = ""
If ComboBox1.SelectedValue > -1 Then 'Something is selected
  ComboVal = ComboBox1.SelectedText
Else
  'By Default you can type text into a ComboBox, if there is
  'text in the combo, and you haven't selected any, you can do
  'something here
End If

need help!!

Tue, 17 Nov 2009 09:06:19 -0700

On my form load event, i populate three comboboxes by code.... in the button click event i try to insert into the database and i use combobox.selecteditem and it generates an insert error.
but when i use combobox.selectedindex, it runs.
dont know wat to do.

Re: dynamic arrays in vb.net ?????

Mon, 16 Nov 2009 13:46:01 -0700

thank u for the info, really helped, im still new to vb.net so im kinda learning as i go, thanx again!

Re: Exit button with yes/no options

Mon, 16 Nov 2009 12:01:16 -0700

If you want a form to close as apposed to a full application

You can use:

Me.Close() (This closes the form you call this code from, if that form is set as the startup form, it will close the whole application)

Application.End (This closes the whole application, may or may not call your Form_Closing and Form_Closed routines of open forms, so be careful)

---
If you open your application from a Sub Main, and you do not specify a form with Application.Run(), then you have to do a Application.End to end the running process.

Hope this helps!

Re: Exit button with yes/no options

Mon, 16 Nov 2009 07:42:32 -0700

Thanks! It helps very much!

Best wishes Sean,

Michael

Re: Exit button with yes/no options

Mon, 16 Nov 2009 07:09:44 -0700

  Dim intrebare As System.Windows.Forms.DialogResult
  intrebare = MsgBox("Doriti parasirea aplicatiei?", MsgBoxStyle.YesNo)
  If intrebare = MsgBoxResult.Yes  Then 
    Me.Close()
  Else 
  End If

Hope this helps!

Re: dynamic arrays in vb.net ?????

Mon, 16 Nov 2009 06:53:14 -0700

You a few options to solve the scenario you are facing.

Firstly, and more directly to your questions, you can declare the size of an array dynamically like this:

'Say I am getting data from the database, and i don't know how
'many rows I am getting...

'At somepoint, I will get a count for the amount of data coming back, and when I get that 'count' i can declare the array like so:

Dim RowCount as Integer = 15

Dim DynamArray(RowCount) As Integer
'Now DynamArray's bounds are 0 - 14

'You can also declare an array with no size:
Dim DynamArray() as Integer

'Then change the length afterwards:
ReDim DynamArray(RowCount)

'And Finally, if you want to add an item to the array:
ReDim Preserve DynamArray(DynamArray.Length)
DynamArray(DynamArray.Length - 1) = Value

Since you understand how to do this enough to have done it in C++, I won't bore you with details... Here is another way to do it, look into using an arrayList, it dynamically holds multiple datatypes

Dim aList As New ArrayList
aList.Add(Object)
aList.Count
aList.Item(0)

dynamic arrays in vb.net ?????

Sun, 15 Nov 2009 19:40:07 -0700

im trying to declare an array with an unknown length and no way of figuring it out untill the actual data has been placed within the array, in c++ it possible to fill a dynamic array with data and then find out the length if u need 2, but in vb.net im not sure, i know abt the redim concept, but does it work in this case...

thank u sooo much !!!

Drag and drop from IE8

Sun, 15 Nov 2009 19:06:46 -0700

I have an app where I let the user select text from a website and drop it into a textbox on my app. This works well when the browser is Firefox, but IE8's protected mode doesn't allow it. In earlier versions when you tried you'd get a pop up asking to authorize it, and if you did it went into the registry into IE's lowrights/dragdrop. It no longer seems to do this. If I already have the lowrights entry, then IF I hold down the ctrl key, it will work.

So does anyone know how I'm supposed to get this to work again? Also what is the ctrl key telling IE8 when I'm doing a drag and drop. I can't find that documented anywhere.

Any help would be greatly appreciated.

Dan

Exit button with yes/no options

Fri, 13 Nov 2009 10:56:23 -0700

Hi everyone and thanks for reading my question!

This is my first topic related on vb.net!

I want to implement an exit button with yes/no option in vb.net.

Here's what I've tried:

Dim intrebare As String
        intrebare = MsgBox("Doriti parasirea aplicatiei?", MsgBoxStyle.YesNo)
        If intrebare = "Yes" Then ' if we press yes it quits vb.net
'here is the problem how to say him if he selects yes to quit from 'visual studio 2008?            

'Me.Close() if I select yes I want that it exits my full 'software , so exits visual studio 2008 is it possible?
           
        Else 
          'ok
            Me.Close()

No syntax error the problem is that even if I select yes or no it returns to me to the initial form. I want to return me on initial form only if I press No Button of MessageBox.

vb6 handles .net com class event

Fri, 13 Nov 2009 08:08:27 -0700

i have the ComClassSearchCustomers class and interface IComClassSearchCustomersat .net which used to create a tlb file. The class raise an event inside new. After that i have a vb6 form Form1 which catch the event , but it never see the event. Any ideas?
Option Strict On
Option Explicit On
Imports System.Runtime.InteropServices

<Guid("BB86EB1C-6444-424f-B83B-A667561E06C3"), _
ComSourceInterfaces(GetType(IComClassSearchCustome rs))> _
Public Class ComClassSearchCustomers

Public Delegate Sub printReportEventHandler(ByVal codes As String)
Public Event printReport As printReportEventHandler

Public Sub New()
MyBase.New()
RaiseEvent printReport(“MARIA”)
End Sub
End Class

Imports System.Runtime.InteropServices

<Guid("D8F7EC74-0EFC-4e43-9B59-4CF741DF616D"), _
InterfaceType(ComInterfaceType.InterfaceIsIDispatc h)> _
Public Interface IComClassSearchCustomers
<DispId(1)> _
Sub printReport(ByVal codes As String)
End Interface
Public WithEvents Instance As Search.ComClassSearchCustomers

Private Sub Form_Load()
Set Instance = New Search.ComClassSearchCustomers
End Sub

Private Sub Instance_printReport(ByVal codes As String)
MsgBox ("raise")
End Sub

Re: Anyone interesed in doing VIRTUAL MALL project

Fri, 13 Nov 2009 07:31:01 -0700

RentACoder.com

FindACoder.com

You'll never learn to program if you have others do the work for you. Even if you feel that you "could" do it, without actually having done it, you are selling yourself short.

Good luck!
SeanCampbell

Re: Anyone interesed in doing VIRTUAL MALL project

Thu, 12 Nov 2009 22:55:27 -0700

Thanks for the reply.....but my problem is that I have to limited time to work on this project as I have other courses also to work on.
And this project was alloted at the last moment, so can you help me out
where to look for right people who can do this project and also how to approach them.

Re: Multidimensional array within a structure

Thu, 12 Nov 2009 17:30:32 -0700

Hi ArisanLiam,

You need 4 instances in your empty shrare 'layer' array variable.>>

Option Strict On
Public Class Form1

    Public Structure layerType
        Public tile(,) As Integer
        Public Sub New(ByVal i As Integer) 'The constructor takes a passed value 
            'from the creation command.
            ReDim tile(i, i)        'I ReDim to the passed integer
        End Sub
    End Structure

    Public Shared layer() As layerType

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        ReDim layer(3)               'Creates 4 entire copies ( 0,1,2 & 3 ) of the STRUCTURE so..

        'Pass the 3 to i in the New SUB for each instance in the layer array.
        layer(0) = New layerType(3)  'Create a new instance of layerType structure for array index 0.
        layer(1) = New layerType(3)  'Create a new instance of layerType structure for array index 1.
        layer(2) = New layerType(3)  'Create a new instance of layerType structure for array index 2.
        layer(3) = New layerType(3)  'Create a new instance of layerType structure for array index 3.

        layer(0).tile(0, 0) = 1      'Works finally.
        layer(3).tile(3, 3) = 1      'No longer gives null reference exception.

    End Sub
End Class

Regards,

Dr M.

Re: Two Dimensional Arrays in VB.NET

Thu, 12 Nov 2009 17:05:48 -0700

Hi SeanCampbell,

I guess you meant

SumHighs = SumHighs + WeatherData(I, 1)

in your last FOR NEXT loop.

Regards,

Dr M

Re: Anyone interesed in doing VIRTUAL MALL project

Thu, 12 Nov 2009 16:53:40 -0700

Hi,

In my experience on online forums, few people will do a full project / homework or an assignment, whatever you call it, for you when you say you are a student.

They may help you in certain areas if you say you are stuck, say on accessing a database. Try some books on Vb.Net from your school / college / university.

Anyone interesed in doing VIRTUAL MALL project

Thu, 12 Nov 2009 15:17:35 -0700

Hi, I a have a small term project titled "Virtual Mall".
Is there someone who is interested in doing this project.
The project is based on VB.Net and SQL Server 2005.
The deadline is Nov 30th.

Let me know who can do this so I can mail the details and get in touch with him/her.
Budget is moderate as I am a student.
Reply ASAP.

Re: Help::Automatic textbox generation

Thu, 12 Nov 2009 11:30:45 -0700

Hi,

I would do this with a button click though, not within a TextChanged event otherwise you will generate New TextBoxes every time the text is changed.

As this looks like a WINDOWS FORM based project you would need.>>

t.Name = "TextBox" & count.ToString

within the FOR NEXT next loop instead of

t.Id = "TextBox" & count.ToString

Remove the line

count = count + 1

as it interferes wih the FOR NEXT loop.

How many TextBoxes are you wanting in the end?

Best of luck and Happy coding.

Re: Help::Automatic textbox generation

Thu, 12 Nov 2009 11:28:56 -0700

Hi,

Move the line of code.>>

Dim t As New TextBox to just after.>>

For count As Integer = 4 to 6

that way you generate a NEW textbox each time.

Give each a Location too. Try

t.Location = New Point(count * 75,50)

within the loop too.

If this is a Web based project you could also try.>>

http://forums.asp.net/

Best of luck and Happy coding.