限制文本框中的值 [英] restrict values in a textbox

问题描述

如何限制vb.net中的文本框条目，使其仅接受数字键和退格键以更正任何错误.

我正在使用此代码:

how to restrict textbox entry in vb.net so that it accepts only numerical key and backspace to correct any error.

I am using this code:

Private Sub TextBox3_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox3.KeyPress
        Dim allowedChars As String = "0123456789"

        If allowedChars.IndexOf(e.KeyChar) = -1 Then
            ' Invalid Character
            e.Handled = True
        End If

    End Sub

但不包括退格编码.
我还需要允许退格键.所以请帮忙.

谢谢！

but its not including the backspace coding.
I need to allow backspace also. So please help.

Thanks!

推荐答案

请检查以下修改后的代码:

Please check the following modified code:

Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
        Dim allowedChars As String = "0123456789"
        If e.KeyChar <> ControlChars.Back Then
            If allowedChars.IndexOf(e.KeyChar) = -1 Then
                ''Invalid Character
                e.Handled = True
            End If
        End If
    End Sub

在If allowedChars.IndexOf(e.KeyChar) = -1 Then之前添加此If Asc(e.KeyChar) = Asc(Keys.Back) Then Exit Sub.

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