在设计时控件的已启用外观？ [英] Control's Enabled appearance at design time?

问题描述

我定义了一个自定义按钮类，该按钮类在启用/禁用按钮时设置背景色。

I defined a custom button class, which sets background color when button is enabled/disabled.

在运行时启用外观（A）：

Enabled appearance at runtime (A):

在运行时（B）禁用外观：

Disabled appearance at runtime (B):

无论 Enabled 的值如何，设计时间外观始终为（A）属性。

Design time appearance is always (A), regardless of the value of Enabled property.

我希望控件在设计器中的显示与运行时的显示完全相同。

I would like my control to appear in designer exactly the way it would appear at run time. Is it possible and, if so, how can do it?

这是我尝试过的内容（仅代码的相关部分）：

Here is what I tried (only relevant parts of the code):

Public Class StyledButton : Inherits Button      
  Private p_fEnabled As Boolean

  <DefaultValue(True)>
  Public Shadows Property Enabled As Boolean
    Get
      Return p_fEnabled
    End Get
    Set(value As Boolean)
      p_fEnabled = value
      MyBase.Enabled = value
      UpdateVisualStyle()
    End Set
  End Property

  Private Sub UpdateVisualStyle()
    If Me.Enabled Then
      'set enabled appearance
    Else
      'set disabled appearance
    End If
  End Sub

End Class

推荐答案

shadowed属性确实可以在运行时设计，而不是在IDE中。您不想丢失 Visible = False 的控件，并且即使 Enabled = False 。由于IDE无意绘制禁用的控件，因此没有理由在更改属性时调用Invalidate。

The shadowed property does work as designed at runtime, just not in the IDE. You would not want to loose controls which are Visible = False, and you would want to drill into Button events even when Enabled = False. Since the IDE has no intention of drawing a disabled control, there is no reason for it to invoke Invalidate when you change the property.

由于它在运行时有效，请在设计器中欺骗它以使用另一个看起来像原始属性的属性：

Since it works at runtime, trick it in the designer to use another property which looks like the original:

<Browsable(False), DebuggerBrowsable(DebuggerBrowsableState.Never),
          EditorBrowsable(False)>
Public Shadows Property Enabled As Boolean
    Get
        Return neoEnabled
    End Get
    Set(value As Boolean)
        neoEnabled = value
    End Set
End Property

一个新属性，为IDE命名正确。

A new property, with the right name for the IDE.

<DisplayName("Enabled")>
Public Property neoEnabled As Boolean
    Get
        Return p_fEnabled
    End Get
    Set(value As Boolean)

        p_fEnabled = value
        UpdateVisualStyle()
        MyBase.Enabled = p_fEnabled

    End Set
End Property

遗憾的是， Enabled 和 neoEnabled 都将由Intellisense在代码中提供，但由于他们俩都做同一件事，这没什么大不了的。测试代码：

Sadly, both Enabled and neoEnabled will be offered by Intellisense in code, but since they both do the same thing, its not a big deal. test code:

Private Sub UpdateVisualStyle()
    If p_fEnabled Then
        ' other interesting stuff
        MyBase.BackColor = Color.Lime
    Else
        MyBase.BackColor = Color.LightGray
    End If

    MyBase.Invalidate()
End Sub

您可能比我更努力，并提出了一个更干净的实现。

You have probably wrestled with it more that I, and come up with a cleaner implementation.

这将保留与 neoEnabled 状态相关的BackColor：

This persists the BackColor associated with neoEnabled state:

'
'StyledButton1
'
Me.StyledButton1.BackColor = System.Drawing.Color.LightGray
Me.StyledButton1.Enabled = False
Me.StyledButton1.neoEnabled = False

对

Me.StyledButton1.BackColor = System.Drawing.Color.Lime
Me.StyledButton1.Enabled = False
Me.StyledButton1.neoEnabled = True

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