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如何使用控件呈现类

此示例演示如何使用 ComboBoxRenderer 类呈现组合框控件的下拉箭头。 该示例包含 OnPaint 简单自定义控件的方法。 该 ComboBoxRenderer.IsSupported 属性用于确定是否在应用程序窗口的工作区中启用视觉样式。 如果视觉样式处于活动状态，则 ComboBoxRenderer.DrawDropDownButton 该方法将使用视觉样式呈现下拉箭头;否则，该方法 ControlPaint.DrawComboButton 将在经典 Windows 样式中呈现下拉箭头。

示例：

    // Render the drop-down arrow with or without visual styles.
protected:
    virtual void OnPaint(PaintEventArgs^ e) override
    {
        __super::OnPaint(e);

        if (!ComboBoxRenderer::IsSupported)
        {
            ControlPaint::DrawComboButton(e->Graphics,
                this->ClientRectangle, ButtonState::Normal);
        }
        else
        {
            ComboBoxRenderer::DrawDropDownButton(e->Graphics,
                this->ClientRectangle, ComboBoxState::Normal);
        }
    }

// Render the drop-down arrow with or without visual styles.
protected override void OnPaint(PaintEventArgs e)
{
    base.OnPaint(e);

    if (!ComboBoxRenderer.IsSupported)
    {
        ControlPaint.DrawComboButton(e.Graphics,
            this.ClientRectangle, ButtonState.Normal);
    }
    else
    {
        ComboBoxRenderer.DrawDropDownButton(e.Graphics,
            this.ClientRectangle, ComboBoxState.Normal);
    }
}

' Render the drop-down arrow with or without visual styles.
Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)
    MyBase.OnPaint(e)

    If Not ComboBoxRenderer.IsSupported Then
        ControlPaint.DrawComboButton(e.Graphics, _
            Me.ClientRectangle, ButtonState.Normal)
    Else
        ComboBoxRenderer.DrawDropDownButton(e.Graphics, _
            Me.ClientRectangle, ComboBoxState.Normal)
    End If
End Sub

编译代码

此示例需要：

另请参阅