how to supress backspace and delete keys

Question

i have a masked text box control that is set for overwrite.  i want to disable backspace and delete keys.  to that end i added the following code to my form...


        private void maskedTextBoxTime_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Back || e.KeyCode == Keys.Delete)
            {
                e.SuppressKeyPress = true;
            }
        }




however, when i run the application and set focus to the masked text box control, backspace and delete continue to function.  what am i doing wrong here?

thanks,

glenn

Answer 1

Historically MaskedTextBox has always bugs and issues related to it.
I did some test with your code and in effect DO NOT WORK, only if you eliminate the mask which has no point.
What i recomment use an alternative to enter the data. For time use DateTimePicker and set Format property to Time.

Answer 2

That's strange, I have no problems with this.  Are you sure you hooked up your event handler to the control? Post the portion of your designer code that declares the MaskedTextBox.

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David Morton - http://blog.davemorton.net/

Answer 3

well, it is not my issue but I did reproduce it. I think you only have to draw the MaskedTextBox in a form, declare a mask and the KeyDown event.

hre is what you ask for:

//

// maskedTextBox1

//

this.maskedTextBox1.Location = new System.Drawing.Point(320, 372);

this.maskedTextBox1.Mask = "90:00";

this.maskedTextBox1.Name = "maskedTextBox1";

this.maskedTextBox1.Size = new System.Drawing.Size(94, 20);

this.maskedTextBox1.TabIndex = 5;

this.maskedTextBox1.ValidatingType = typeof(System.DateTime);

this.maskedTextBox1.KeyDown += new System.Windows.Forms.KeyEventHandler(this.maskedTextBox1_KeyDown);