如何：呈现视觉样式元素

  • 项目

System.Windows.Forms.VisualStyles 命名空间公开 VisualStyleElement 对象，这些对象表示视觉样式支持的 Windows 用户界面 (UI) 元素。 本主题演示如何使用 VisualStyleRenderer 类呈现表示“开始”菜单的“注销”和“关闭”按钮的 VisualStyleElement。

呈现视觉样式元素

  1. 创建 VisualStyleRenderer 并将其设置为要绘制的元素。 请注意 Application.RenderWithVisualStyles 属性和 VisualStyleRenderer.IsElementDefined 方法的使用；如果禁用了视觉样式或未定义元素，则 VisualStyleRenderer 构造函数将引发异常。

    private:
    VisualStyleRenderer^ renderer;
    VisualStyleElement^ element;

public:
    CustomControl()
    {
        this->Location = Point(50, 50);
        this->Size = System::Drawing::Size(200, 200);
        this->BackColor = SystemColors::ActiveBorder;
        this->element = 
            VisualStyleElement::StartPanel::LogOffButtons::Normal;
        if (Application::RenderWithVisualStyles &&
            VisualStyleRenderer::IsElementDefined(element))
        {
            renderer = gcnew VisualStyleRenderer(element);
        }
    }

    private VisualStyleRenderer renderer = null;
private readonly VisualStyleElement element =
    VisualStyleElement.StartPanel.LogOffButtons.Normal;

public CustomControl()
{
    this.Location = new Point(50, 50);
    this.Size = new Size(200, 200);
    this.BackColor = SystemColors.ActiveBorder;

    if (Application.RenderWithVisualStyles &&
        VisualStyleRenderer.IsElementDefined(element))
    {
        renderer = new VisualStyleRenderer(element);
    }
}

    Private renderer As VisualStyleRenderer = Nothing
Private element As VisualStyleElement = _
    VisualStyleElement.StartPanel.LogOffButtons.Normal

Public Sub New()
    Me.Location = New Point(50, 50)
    Me.Size = New Size(200, 200)
    Me.BackColor = SystemColors.ActiveBorder

    If Application.RenderWithVisualStyles And _
        VisualStyleRenderer.IsElementDefined(element) Then
            renderer = New VisualStyleRenderer(element)
    End If
End Sub

  2. 调用 DrawBackground 方法来呈现 VisualStyleRenderer 当前表示的元素。

    protected:
    virtual void OnPaint(PaintEventArgs^ e) override
    {
        // Draw the element if the renderer has been set.
        if (renderer != nullptr)
        {
            renderer->DrawBackground(e->Graphics, this->ClientRectangle);
        }

        // Visual styles are disabled or the element is undefined,
        // so just draw a message.
        else
        {
            this->Text = "Visual styles are disabled.";
            TextRenderer::DrawText(e->Graphics, this->Text, this->Font,
                Point(0, 0), this->ForeColor);
        }
    }

    protected override void OnPaint(PaintEventArgs e)
{
    // Draw the element if the renderer has been set.
    if (renderer != null)
    {
        renderer.DrawBackground(e.Graphics, this.ClientRectangle);
    }

    // Visual styles are disabled or the element is undefined,
    // so just draw a message.
    else
    {
        this.Text = "Visual styles are disabled.";
        TextRenderer.DrawText(e.Graphics, this.Text, this.Font,
            new Point(0, 0), this.ForeColor);
    }
}

    Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)
    ' Draw the element if the renderer has been set.
    If (renderer IsNot Nothing) Then
        renderer.DrawBackground(e.Graphics, Me.ClientRectangle)

    ' Visual styles are disabled or the element is undefined, 
    ' so just draw a message.
    Else
        Me.Text = "Visual styles are disabled."
        TextRenderer.DrawText(e.Graphics, Me.Text, Me.Font, _
            New Point(0, 0), Me.ForeColor)
    End If
End Sub

编译代码

此示例需要：

另请参阅