VB.net：只允许数字，在WPF中复制粘贴回空格删除？

Question

how do I only allow digits , no . , - . , - , and also copy paste Ctrl C + Ctrl V, backspace and delete in a textbox in VB.net WPF ?

As it is WPF, the keystrokes and keypresses do not work. I do not know the solution to this.

I cannot seem to find a solution for this, without this my program will break every time someone enters anything other than digits. Please help!

Answer 1

In cases like this, I tend to use the numericUpDown control from the VB Toolbox. It only accepts numeric values and has some handy buttons to increase or decrease the value. Also, you can set a minimum and maximum value.

Answer 2

Oh, i found the answer, just include this function.

Protected Overrides Sub OnPreviewTextInput(e As    
System.Windows.Input.TextCompositionEventArgs)
e.Handled = Not AreAllValidNumericChars(e.Text)
MyBase.OnPreviewTextInput(e)
End Sub


Private Function AreAllValidNumericChars(str As String) As Boolean
For Each c As Char In str
    If Not [Char].IsNumber(c) Then
        Return False
    End If
Next
Return True

End Function`

Answer 3

this simple code will help you to put numeric only for textboxes on VB.net WPF

Private Sub txtTextBox_PreviewKeyDown(sender As Object, e As KeyRoutedEventArgs) Handles txtTextBox.PreviewKeyDown
    If e.Key <> 8 Then
        '48 - 57  = Ascii codes for numeric only
        If e.Key < 48 Or e.Key > 57 Then
            e.Handled = True
        End If
    End If
End Sub