How to use the KeyPress event
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Hello, I am a newbie at C#. I am trying to make a text box only allow alpha characters, such as a - z upper and lower case, the backspace, and space keys. How would i write that in the keypress event and how do i get it to activate on that text box? thanks any help will be appreciated.
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Hello, I am a newbie at C#. I am trying to make a text box only allow alpha characters, such as a - z upper and lower case, the backspace, and space keys. How would i write that in the keypress event and how do i get it to activate on that text box? thanks any help will be appreciated.
Something like this should get you started:
private void textBox1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
{
// Allow only alpha characters
base.OnKeyPress(e);
if (Char.IsLetter(e.KeyChar) || Char.IsPunctuation(e.KeyChar)
|| Char.IsSeparator(e.KeyChar) || Char.GetNumericValue(e.KeyChar) == -1)
e.Handled = false;
else
e.Handled = true;
}-Nick Parker
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Something like this should get you started:
private void textBox1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
{
// Allow only alpha characters
base.OnKeyPress(e);
if (Char.IsLetter(e.KeyChar) || Char.IsPunctuation(e.KeyChar)
|| Char.IsSeparator(e.KeyChar) || Char.GetNumericValue(e.KeyChar) == -1)
e.Handled = false;
else
e.Handled = true;
}-Nick Parker
well thanks for the help anyways but it doesn't work. i can still type numbers and wierd characters into the text box. Does anyone else have any ideals?here is what my teacher showed us in class but i can't get anything out of it? thanks private void Form1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e) { if (e.KeyChar < 'a'||e.KeyChar > 'z')&& e.KeyChar != '\b') e.Handled = true; }
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Hello, I am a newbie at C#. I am trying to make a text box only allow alpha characters, such as a - z upper and lower case, the backspace, and space keys. How would i write that in the keypress event and how do i get it to activate on that text box? thanks any help will be appreciated.
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well thanks for the help anyways but it doesn't work. i can still type numbers and wierd characters into the text box. Does anyone else have any ideals?here is what my teacher showed us in class but i can't get anything out of it? thanks private void Form1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e) { if (e.KeyChar < 'a'||e.KeyChar > 'z')&& e.KeyChar != '\b') e.Handled = true; }
kharr1027 wrote: private void Form1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e) { if (e.KeyChar < 'a'||e.KeyChar > 'z')&& e.KeyChar != '\b') e.Handled = true; } A few things, first of all I just re-tried the code example I gave you and it does work, however I noticed in the code example you listed you have
Form1_KeyPresswhich appears that you have an event handler registered for theKeyPressevent of aForm, not aTextBox. Make sure whatever the name of your textbox that you add to your form includes the following event/delegate assignment (for this example the name of my textbox is simply the default oftextBox1):this.textBox1.KeyPress += new System.Windows.Forms.KeyPressEventHandler(this.textBox1_KeyPress);
then the following will work to only allow alphabetic characters, space and backspace entries:
private void textBox1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
{
// Allow only alpha characters
base.OnKeyPress(e);
if (Char.IsLetter(e.KeyChar) || Char.IsPunctuation(e.KeyChar)
|| Char.IsSeparator(e.KeyChar) || Char.GetNumericValue(e.KeyChar) == -1)
e.Handled = false;
else
e.Handled = true;
}-Nick Parker