CODEWITHSUNDEEP
vb.net
SpongeBob SquarePants
SpongeBob SquarePants

Reputation: 1055

Getting rid of unwanted characters in the textbox

I am trying to show the square root of the number entered in the textbox. when the user presses Q (Uppercase), the square Root should be shown (in the textbox). I did manage to get the sqaure root, but the problem is that when I press Q the Letter Q is also typed in. For example, if I enter 25 in the textbox and press Q then I get Q5 as the result. Is there any work around to this problem ? Below is the code that I have used.

Private Sub Textbox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress

    If e.KeyChar = Chr(81) Then                             '81 for Letter Q 
        Dim root As Double = Math.Sqrt(Val(TextBox1.Text))
        TextBox1.Text = root
    End If
End Sub

Upvotes: 0

Views: 551

Answers (3)

Lorenz
Lorenz

Reputation: 129

Catch the whole thing via event:

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

public void q_pushed(object sender, KeyEventArgs e)
{
   if(e.KeyCode == Keys.Q)
   {
     //DoStuff
   }
}

This should do what you need :)

Upvotes: 0

Gustavo Del Castillo
Gustavo Del Castillo

Reputation: 26

You can just add this line

e.KeyChar = ""

Inside your if statement, it would look like this:

Private Sub TextBox1_KeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
        If e.KeyChar = Chr(81) Then                             '81 for Letter Q 
            Dim root As Double = Math.Sqrt(Val(TextBox1.Text))
            TextBox1.Text = root
            e.KeyChar = ""
        End If
    End Sub

Upvotes: 1

Developer
Developer

Reputation: 8636

Why you are accepting characters block all the letters using ASCII values

Upvotes: 0

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