Question

任何哥们请更正我的脚本，TextBox变量已完成工作，但MaskTextBox在此error中返回了EnterEvent。

我想为event-handling和TextBox使用MaskTextBox的一个功能

    Private Sub TextBox_Enter(sender As Object, e As EventArgs) Handles OrgNameTextBox.Enter, AddressTextBox.Enter, ContactNumMaskedTextBox.Enter
        Dim Tb As TextBox = CType(sender, TextBox)
        Dim Mtb As MaskedTextBox = CType(sender, MaskedTextBox)
        If Type = MASKTEXTBOX Then
            MTb.BackColor = Color.Yellow
            MTb.ForeColor = Color.Black
        ElseIf Type = TextBox Then
            Tb.BackColor = Color.Yellow
            Tb.ForeColor = Color.Black
        End If
    End Sub

Answer 1

由于始终存在类型转换错误，因此事件处理程序无法工作正确的版本是

Private Sub TextBox_Enter(sender As Object, e As EventArgs) Handles OrgNameTextBox.Enter, AddressTextBox.Enter, ContactNumMaskedTextBox.Enter
    If TypeOf sender Is MaskedTextBox Then
        Dim Mtb As MaskedTextBox = CType(sender, MaskedTextBox)
        Mtb.BackColor = Color.Yellow
        Mtb.ForeColor = Color.Black
    ElseIf TypeOf sender Is TextBox Then
        Dim Tb As TextBox = CType(sender, TextBox)
        Tb.BackColor = Color.Yellow
        Tb.ForeColor = Color.Black
    End If
End Sub

更好地使用两个控件TextBoxBase的共同祖先

Private Sub TextBox_Enter(sender As Object, e As EventArgs) Handles OrgNameTextBox.Enter, AddressTextBox.Enter, ContactNumMaskedTextBox.Enter
    Dim bt As TextBoxBase = TryCast(sender, TextBoxBase)
    If bt IsNot Nothing Then
        bt.BackColor = Color.Yellow
        bt.ForeColor = Color.Black
    End If
End Sub

Answer 2

我经常使用@Jimi及其工作示例...

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<div class='ex1'>
<a href="//app.google.com">app google</a> 
<a href="//www.info.google.com">info google</a>
<a href="https://google.com/abc">google abc</a>
<a href="https://www.apple.com">apple</a>
</div>

<hr/>

<div class='ex2'>
<a href="//app.google.com">app google</a> 
<a href="//www.info.google.com">info google</a>
<a href="http://wwwtst.google.com/abc">google abc</a>
<a href="https//wwwdev.apple.com">apple</a>
</div>

如何在没有InvalidCastException的情况下处理TextBox和MaskTextBox的事件？

2 个答案: