What is the subtract key enumeration?

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Hi there,

I have been trying to find out which number I need to use in order for my text box to allow a negative value input. I've tried all the suggested ones I can find; 189, 109 and Key.Subtract, but none of these are working for me.

Below is the code in which I am trying to put it.

Can anyone please help me?

Thank you and many kind regards.

What I have tried:

char ch = e.KeyChar;

            if (!Char.IsDigit(ch) && ch != 8 && ch != 46 && ch != 110 && ch != 189 && ch != 13)
            {
                e.Handled = true;
                MessageBox.Show("Please Enter Valid Input");
            }

Posted 26-Mar-17 8:15am

Member 13068046

Updated 26-Mar-17 10:45am

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[no name] 26-Mar-17 14:23pm

96

Member 13068046 26-Mar-17 14:26pm

Sorry, just tried it and that's not it either. Thank you though.

[no name] 26-Mar-17 14:52pm

What? You mean the ASCII charts are all wrong? You should tell them so they correct the charts!

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OriginalGriff · Answer 1 · 2017-03-26T08:44:00

Solution 1

Put a breakpoint on the "if" line.
Run your app in the debugger.
Click on the TextBox.
Press '-'.
Look at the content of ch

Posted 26-Mar-17 8:44am

OriginalGriff

Dave Kreskowiak · Answer 2 · 2017-03-26T10:45:00

Creating a numeric only TextBox isn't that simple.

Do you have code in place to handle copying and pasting from the textbox? Probably not.

Sure, you're limiting key presses, but how about pasting in a non-numeric value?

How about the arrow keys?

Delete and Backspace?

By the way, you should be making a new TextBox control that only accepts values. I sure hope you're not putting this code in your Form.