Question

I created a GUI and the ValueBox.Text is the string “randomstring”. What I want to do is:

if the ValueBox.Text has numbers only double valueLenght = Convert.ToDouble(ValueBox.Text); else if it has characters && numbers or only characters, then I thought that from MSDN that Convert.ToDouble(string) would return 0. Which is not the case here. The code goes to :

protected override void Dispose(bool disposing)
{
    if (disposing && (components != null))
    {
        components.Dispose();
    }

    base.Dispose(disposing);
}

Then gives an exception from mscorlib

Answer 1

Convert.ToDouble throws an exception if it cannot convert a string to a number.

You likely want to try Double.TryParse. The return value will be true if the conversion succeeded, and false if not. The out double parameter receives the result.