XPS OM 画笔

本主题介绍如何在 XPS OM 中使用不同类型的画笔。

XPS OM 中的画笔基于 IXpsOMBrush 接口,其中包括

平铺画笔

渐变画笔

代码示例

创建纯色画笔

下面的代码示例根据代码中定义的颜色值创建纯色画笔。

    HRESULT                hr = S_OK;

    XPS_COLOR              xpsColor;
    IXpsOMSolidColorBrush  *brush;

    // creates a solid red brush
    xpsColor.colorType = XPS_COLOR_TYPE_SRGB;
    xpsColor.value.sRGB.alpha = 0xFF;
    xpsColor.value.sRGB.red = 0xFF;
    xpsColor.value.sRGB.green = 0x00;
    xpsColor.value.sRGB.blue = 0x00;

    hr = xpsFactory->CreateSolidColorBrush(
       &xpsColor, 
       NULL, 
       reinterpret_cast<IXpsOMSolidColorBrush**>(&brush));
    
    // use brush

    // when finished with brush, release pointer
    brush->Release();

创建视觉画笔

下面的代码示例根据视觉对象创建画笔。

    HRESULT                       hr = S_OK;
    IXpsOMVisualBrush             *brush;

    XPS_RECT viewBoxRect = {0,0,0,0};
    XPS_RECT viewPortRect = {0,0,0,0};

    // set viewBoxRect to define the portion of the visual to use
    // as the brush.
    //
    // set viewPortRect to define the location and size of the 
    // the brush in the destination 
    //
    // create the brush
    hr = xpsFactory->CreateVisualBrush (
        &viewBoxRect,
        &viewPortRect,
        reinterpret_cast<IXpsOMVisualBrush**>(&brush));

    // assign the visual object
    //   brushVisual points to a visual
    //   that is defined outside of this example

    hr = brush->SetVisualLocal (brushVisual);
    
    // use brush
    
    // when finished with brush, release pointer
    brush->Release();
    

创建图像画笔

请参阅将图像放置在 XPS OM 中中的代码示例。

创建线性渐变画笔

下面的代码示例创建线性渐变画笔。 渐变有两个渐变停止点。

    HRESULT                       hr = S_OK;
    XPS_COLOR                     xpsColorStop;
    IXpsOMGradientStop            *xpsGradientStop1, *xpsGradientStop2;
    IXpsOMLinearGradientBrush     *brush;
    XPS_POINT                     startPoint, endPoint;

    // define the start color
    xpsColorStop.colorType        = XPS_COLOR_TYPE_SRGB;
    xpsColorStop.value.sRGB.alpha = 0xFF;
    xpsColorStop.value.sRGB.red   = 0xE4;
    xpsColorStop.value.sRGB.green = 0x3B;
    xpsColorStop.value.sRGB.blue  = 0x2F;
    
    // create a gradient stop by setting the color and location 
    // for the beginning of the gradient
    hr = xpsFactory->CreateGradientStop(
        &xpsColorStop, 
        NULL, 
        0.0f,
        &xpsGradientStop1);
    startPoint.x = 375.75f;
    startPoint.y = 18.0f;

    // define the end color
    xpsColorStop.colorType        = XPS_COLOR_TYPE_SRGB;
    xpsColorStop.value.sRGB.alpha = 0xFF;
    xpsColorStop.value.sRGB.red   = 0xEF;
    xpsColorStop.value.sRGB.green = 0x79;
    xpsColorStop.value.sRGB.blue  = 0x2F;

    // create a gradient stop by setting the color and  location
    //  for the end of the gradient
    hr = xpsFactory->CreateGradientStop(
        &xpsColorStop,
        NULL, 
        1.0f, 
        &xpsGradientStop2);
    endPoint.x   = 375.75f;
    endPoint.y   = 134.6f;

    // create the brush
    hr = xpsFactory->CreateLinearGradientBrush(
        xpsGradientStop1, 
        xpsGradientStop2, 
        &startPoint, 
        &endPoint, 
        &brush);
    // release gradient stops after creating brush
    xpsGradientStop1->Release();
    xpsGradientStop2->Release();

    // when finished with brush, release pointer to brush
    brush->Release();

IXpsOMGradientBrush 接口

IXpsOMImageBrush 接口

IXpsOMLinearGradientBrush 接口

IXpsOMRadialGradientBrush 接口

IXpsOMSolidColorBrush 接口

IXpsOMTileBrush 接口

IXpsOMVisualBrush 接口

XPS_COLOR

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