keypress style for alphanumeric textbox help plz.

there are actually a few ways to do this. one involves overriding the textbox control. The other, (quick and dirty and less OO oriented way) is to:

1) Set the form property KeyPreview = true

this.KeyPreview = true;

2) place your textbox in the form

3) hook up the textbox event handler for keypress

this.textBox1.KeyPress += new System.Windows.Forms.KeyPressEventHandler(this.textBox1_KeyPress);

4) override the event handler textBox1_KeyPress as shown below:

private void textBox1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
{
   char nextChar = (char)e.KeyChar;
   Regex patternMatters = new Regex("[0-9A-Za-z_]+");
   if (patternMatters.Match(nextChar.ToString()).Success)
    {
        e.Handled = false;
    }
else
   {
     e.Handled = true;
   }

}

5) Don't forget to add the using statement for regular expression use

using System.Text.RegularExpressions;

Hope this helps!

-Mike G. (Microsoft MVP)

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Mike Gold20y ago
there are actually a few ways to do this. one involves overriding the textbox control. The other, (quick and dirty and less OO oriented way) is to:

1) Set the form property KeyPreview = true

this.KeyPreview = true;
2) place your textbox in the form

3) hook up the textbox event handler for keypress

this.textBox1.KeyPress += new System.Windows.Forms.KeyPressEventHandler(this.textBox1_KeyPress);

4) override the event handler textBox1_KeyPress as shown below:

private void textBox1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
{
   char nextChar = (char)e.KeyChar;
   Regex patternMatters = new Regex("[0-9A-Za-z_]+");
   if (patternMatters.Match(nextChar.ToString()).Success)
    {
        e.Handled = false;
    }
else
   {
     e.Handled = true;
   }

}

5) Don't forget to add the using statement for regular expression use

using System.Text.RegularExpressions;

Hope this helps!

-Mike G. (Microsoft MVP)

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