I am using windows forms and i am trying to get some doubles as input to do some calculations

The input is in textBox which is by default String, it needs to be converted to the type i am using,

I am doing this on the
public void textBox2_TextChanged(object sender, EventArgs e)
{}
method.

I have tried the followings:
double a;

a = Convert.ToDouble(textBox2.Text);
a = Double.Parse(textBox2.Text);

but both of them have a runtime error, Format Exception was unhandled
Input string was not in a correct format.

Any idea to solve the problem??

Hello.

There is nothing wrong about : double a=double.parse(txtbox.text); thats for sure ...

You get the error in run time i guess cause there is no numbers in text.

Anyway you can try this...

double a;
bool parsed;

parsed = double.tryParse(txtbox.text,a);

If(parsed) { messagebox.show("a="+a.toString()); }
else { messagebox.Show("Could not be parsed"); }