子类化 NumericUpDown 控件

Question

我根据自己的需要从here 举例子类化了一个文本框

以同样的方式，我尝试继承 NumericUpDown 控件以获取它们的 selectAll 功能，并将如果点 (".") 字符按下为逗号 (",") 字符以适应更适合我的语言环境的 NumericUpDown 控件。

但我不能这样做，因为 NumericUpDown 没有像文本框那样的相同属性，我希望这两个控件的行为方式相同。

在我的代码中仍然存在两个问题，SelectAll 和 SelectionLength：

Option Explicit On
Option Strict On

Public Class xNumericUpDown
Inherits NumericUpDown

Private alreadyFocused As Boolean

Protected Overrides Sub OnLeave(ByVal e As EventArgs)
    MyBase.OnLeave(e)

    Me.alreadyFocused = False

End Sub

Protected Overrides Sub OnGotFocus(ByVal e As EventArgs)
    MyBase.OnGotFocus(e)

    If MouseButtons = MouseButtons.None Then

        Me.SelectAll() ' HOW TO MAKE SELECTALL SUB FOR NUMERICUPDOWN?
        Me.alreadyFocused = True

    End If
End Sub

Protected Overrides Sub OnMouseUp(ByVal mevent As MouseEventArgs)
    MyBase.OnMouseUp(mevent)

    If Not Me.alreadyFocused AndAlso Me.SelectionLength = 0 Then ' HOW TO CHECK SELECTIONLENGTH FOR NUMERICUPDOWN?

        Me.alreadyFocused = True
        Me.SelectAll() ' HOW TO MAKE SELECTALL SUB FOR NUMERICUPDOWN?

    End If
End Sub

Protected Overrides Sub OnKeyPress(ByVal keyevent As KeyPressEventArgs)
    MyBase.OnKeyPress(keyevent)

    If keyevent.KeyChar = "." Then
        keyevent.KeyChar = CChar(",")
    End If
End Sub

End Class

请帮助完成这项工作。

Answer 1

检查长度并选择所有文本试试这个：

If Not Me.alreadyFocused AndAlso Me.Text.Length = 0 Then 'Though I suspect it should be <> 0

   Me.alreadyFocused = True
   Me.Select(0, Me.Text.Length)

End If

对于字符替换，试试这个（未经测试）：

If keyevent.KeyChar = "."c Then
      keyevent.Handled = True
      SendKeys.Send(",")
End If