VisualStyleRenderer.DrawBackground 方法

public:
 void DrawBackground(System::Drawing::IDeviceContext ^ dc, System::Drawing::Rectangle bounds);

public void DrawBackground (System.Drawing.IDeviceContext dc, System.Drawing.Rectangle bounds);

member this.DrawBackground : System.Drawing.IDeviceContext * System.Drawing.Rectangle -> unit

Public Sub DrawBackground (dc As IDeviceContext, bounds As Rectangle)

参数

例外

示例

下面的代码示例演示如何使用 DrawBackground(IDeviceContext, Rectangle) 方法在自定义控件的 OnPaint 方法内绘制 VisualStyleElement 。 此代码示例是为类概述提供的更大示例的 VisualStyleRenderer 一部分。

protected:
    virtual void OnPaint(PaintEventArgs^ e) override
    {
        __super::OnPaint(e);

        // Ensure that visual styles are supported.
        if (!Application::RenderWithVisualStyles)
        {
            this->Text = "Visual styles are not enabled.";
            TextRenderer::DrawText(e->Graphics, this->Text,
                this->Font, this->Location, this->ForeColor);
            return;
        }

        // Set the clip region to define the curved corners
        // of the caption.
        SetClipRegion();

        // Draw each part of the window.
        for each(KeyValuePair<String^, VisualStyleElement^>^ entry
            in windowElements)
        {
            if (SetRenderer(entry->Value))
            {
                renderer->DrawBackground(e->Graphics,
                    elementRectangles[entry->Key]);
            }
        }

        // Draw the caption text.
        TextRenderer::DrawText(e->Graphics, this->Text, this->Font,
            elementRectangles["windowCaption"], Color::White,
            TextFormatFlags::VerticalCenter |
            TextFormatFlags::HorizontalCenter);
    }

protected override void OnPaint(PaintEventArgs e)
{
    base.OnPaint(e);

    // Ensure that visual styles are supported.
    if (!Application.RenderWithVisualStyles)
    {
        this.Text = "Visual styles are not enabled.";
        TextRenderer.DrawText(e.Graphics, this.Text,
            this.Font, this.Location, this.ForeColor);
        return;
    }

    // Set the clip region to define the curved corners 
    // of the caption.
    SetClipRegion();

    // Draw each part of the window.
    foreach (KeyValuePair<string, VisualStyleElement> entry
        in windowElements)
    {
        if (SetRenderer(entry.Value))
        {
            renderer.DrawBackground(e.Graphics,
                elementRectangles[entry.Key]);
        }
    }

    // Draw the caption text.
    TextRenderer.DrawText(e.Graphics, this.Text, this.Font,
        elementRectangles["windowCaption"], Color.White,
        TextFormatFlags.VerticalCenter |
        TextFormatFlags.HorizontalCenter);
}

Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)
    MyBase.OnPaint(e)

    ' Ensure that visual styles are supported.
    If Not Application.RenderWithVisualStyles Then
        Me.Text = "Visual styles are not enabled."
        TextRenderer.DrawText(e.Graphics, Me.Text, Me.Font, _
            Me.Location, Me.ForeColor)
        Return
    End If

    ' Set the clip region to define the curved corners of 
    ' the caption.
    SetClipRegion()

    ' Draw each part of the window.
    Dim entry As KeyValuePair(Of String, VisualStyleElement)
    For Each entry In windowElements
        If SetRenderer(entry.Value) Then
            renderer.DrawBackground(e.Graphics, _
                elementRectangles(entry.Key))
        End If
    Next entry

    ' Draw the caption text.
    TextRenderer.DrawText(e.Graphics, Me.Text, Me.Font, _
        elementRectangles("windowCaption"), Color.White, _
        TextFormatFlags.VerticalCenter Or _
        TextFormatFlags.HorizontalCenter)
End Sub

注解

此方法绘制由 Class、 Part和 State 属性指定的当前视觉样式元素的背景。

Width如果 参数指定的bounds矩形的 或 Height 小于 0，该方法DrawBackground将返回而不绘制背景。

视觉样式元素的背景可以是位图文件或填充边框。 若要确定背景类型，请使用 GetEnumValue 参数值 EnumProperty.BackgroundType调用 方法。 若要确定元素背景是否会缩放以适应指定的边界，请使用参数值 EnumProperty.SizingType调用 GetEnumValue 方法。

public:
 void DrawBackground(System::Drawing::IDeviceContext ^ dc, System::Drawing::Rectangle bounds, System::Drawing::Rectangle clipRectangle);

public void DrawBackground (System.Drawing.IDeviceContext dc, System.Drawing.Rectangle bounds, System.Drawing.Rectangle clipRectangle);

member this.DrawBackground : System.Drawing.IDeviceContext * System.Drawing.Rectangle * System.Drawing.Rectangle -> unit

Public Sub DrawBackground (dc As IDeviceContext, bounds As Rectangle, clipRectangle As Rectangle)

参数

例外

注解

此方法绘制由 Class、 Part和 State 属性指定的当前视觉样式元素的背景。 背景将剪裁到 参数指定的 clipRectangle 区域。

Width如果 或 Height 参数指定的bounds矩形的 或 clipRectangle 小于 0，该方法DrawBackground将返回而不绘制背景。

视觉样式元素的背景可以是位图文件或填充边框。 若要确定背景类型，请使用 GetEnumValue 参数值 EnumProperty.BackgroundType调用 方法。 若要确定元素背景是否会缩放以适应指定的边界，请使用参数值 EnumProperty.SizingType调用 GetEnumValue 方法。