如何通过鼠标单击vb.net启用禁用的文本框

Question

如何启用通过单击禁用的文本框的简单方法？怎么做的？

我的代码不起作用

Private Sub Textbox1_MouseClick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Textbox1.MouseClick
    Textbox1.Enabled = True
End Sub

谁能帮我吗.

我是否必须使用定时器等跟踪鼠标点击和文本框的X,Y位置.点击它不会触发任何事件？

Answer 1

您可以使用IMessageFilter捕获WM_LBUTTONDOWN消息,然后检查光标是否在TextBox中...类似于:

Public Class Form1

    Private WithEvents filter As New MyFilter

    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        TextBox1.Enabled = False
        Application.AddMessageFilter(filter)
    End Sub

    Private Sub filter_LeftClick() Handles filter.LeftClick
        Dim rc As Rectangle = TextBox1.RectangleToScreen(TextBox1.ClientRectangle)
        If rc.Contains(Cursor.Position) AndAlso Not TextBox1.Enabled Then
            TextBox1.Enabled = True
            TextBox1.Focus()
        End If
    End Sub

    Private Class MyFilter
        Implements IMessageFilter

        Public Event LeftClick()
        Private Const WM_LBUTTONDOWN As Integer = &H201

        Public Function PreFilterMessage(ByRef m As System.Windows.Forms.Message) As Boolean Implements System.Windows.Forms.IMessageFilter.PreFilterMessage
            Select Case m.Msg
                Case WM_LBUTTONDOWN
                    RaiseEvent LeftClick()

            End Select
            Return False
        End Function

    End Class

End Class