如果是的话,下面的代码就行
Private Sub TextBox1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.Click
TextBox1.Select(0, Len(TextBox1.Text))
End Sub
Private Sub txtPassWord_GotFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtPassWord.GotFocus
With txtPassWord
.SelectionStart = 0
.SelectionLength = Len(.Text)
End With
End Sub