Colocar imágenes en un modelo de objetos XPS
Describe cómo colocar imágenes en un modelo de objetos XPS.
Para colocar imágenes en un modelo de objetos XPS, cree un objeto path que defina la ubicación y el contorno de una imagen y, después, use un pincel de imagen para rellenar la ruta de acceso (path). Agregue el objeto path creado a la lista de objetos visuales de la página o lienzo para que se pueda representar con el otro contenido visual.
Antes de usar estos ejemplos de código en el programa, lea la declinación de responsabilidades en Tareas comunes de programación de documentos XPS.
Ejemplo de código
Creación de un recurso de imagen
Si la imagen de origen no está disponible en el modelo de objetos XPS como un recurso de imagen, cree primero el recurso de imagen:
HRESULT hr = S_OK;
IStreamPtr imageStream; // the resulting image stream
IOpcPartUri *imagePartUri;
IXpsOMImageResource *imageResource;
XPS_RECT rect = {0.0f, 0.0f, 0.0f, 0.0f}; // set to image size
hr = xpsFactory->CreateReadOnlyStreamOnFile (
imageFileName, &imageStream );
hr = xpsFactory->CreatePartUri( imagePartName, &imagePartUri );
imageType; // set to type of image being read in
hr = xpsFactory->CreateImageResource (
imageStream,
imageType,
imagePartUri,
&imageResource);
imagePartUri->Release();
imageStream->Release();
// imageResource can now be used by other parts in the XPS OM.
Colocar la imagen en la colección visual
Si la imagen de origen está disponible en el modelo de objetos XPS como un recurso de imagen, se puede usar para crear un objeto de pincel de imagen y agregarlo como pincel de relleno a la ruta de acceso que describe la ubicación y el tamaño de la imagen en la página.
// These variables are initialized outside of this code example,
// for example, as the parameters of a method or from some
// preceding program code.
// dimensions of the image in pixels
XPS_SIZE bmpDim = {0,0} ;
// DPI resolution values obtained from image
FLOAT dpiX = 96.0f;
FLOAT dpiY = 96.0f;
// initialize viewport values
XPS_RECT viewPort = {0.0,0.0,0.0,0.0};
// initialize viewbox values
XPS_RECT viewBox = {0.0,0.0,0.0,0.0};
// These are part of this code example.
IXpsOMPath *imageRectPath;
IXpsOMImageBrush *imageBrush;
IXpsOMVisualCollection *pageVisuals;
// Describe image source dimensions and set viewbox to be the
// entire image DIP width of image.
// Example:
// 600 image pixels, 300 dpi -> 2 inches -> 2 * 96 = 192 DIP width
viewBox.width = FLOAT((double)bmpDim.width * 96.0 / dpiX);
viewBox.height = FLOAT((double)bmpDim.height * 96.0 / dpiY);
// Describe the size and position of the image destination.
// rect is an XPS_RECT structure that is initialized outside
// of this sample for example, it might be passed in as a parameter.
// destination rectangle
viewPort.x = rect.x;
viewPort.y = rect.y;
viewPort.width = rect.width;
viewPort.height = rect.height;
// Create the image brush.
hr = xpsFactory->CreateImageBrush(imageResource, &viewBox, &viewPort,
reinterpret_cast<IXpsOMImageBrush**>(&imageBrush));
// Create the path that describes the outline of the image on the page.
// This step uses the function described in the next code example.
hr = CreateRectanglePath(xpsFactory, &rect,
reinterpret_cast<IXpsOMPath**>(&imageRectPath));
// Set the accessibility description for the path object as required.
hr = imageRectPath->SetAccessibilityShortDescription( shortDescText );
// Set the image brush to be the fill brush for this path.
hr = imageRectPath->SetFillBrushLocal( imageBrush );
// Get the list of visuals for this page...
hr = xpsPage->GetVisuals( &pageVisuals );
// ...and add the completed path to the list.
hr = pageVisuals->Append( imageRectPath );
// Release locally created interfaces.
if (NULL != pageVisuals) pageVisuals->Release();
if (NULL != imageRectPath) imageRectPath->Release();
if (NULL != imageBrush) imageBrush->Release();
Creación de un objeto path para la imagen
El método siguiente acepta una estructura XPS_RECT y crea una ruta de acceso rectangular.
HRESULT
CreateRectanglePath(
__in IXpsOMObjectFactory *xpsFactory,
__in const XPS_RECT *rect,
__out IXpsOMPath **rectPath
)
{
HRESULT hr = S_OK;
IXpsOMGeometryFigure *rectFigure;
IXpsOMGeometry *imageRectGeometry;
IXpsOMGeometryFigureCollection *geomFigureCollection;
// Define start point and three of the four sides of the rectangle.
// The fourth side is implied by setting the path type to CLOSED.
XPS_POINT startPoint = {rect->x, rect->y};
XPS_SEGMENT_TYPE segmentTypes[3] = {
XPS_SEGMENT_TYPE_LINE,
XPS_SEGMENT_TYPE_LINE,
XPS_SEGMENT_TYPE_LINE
};
FLOAT segmentData[6] = {
rect->x, rect->y+rect->height,
rect->x+rect->width, rect->y+rect->height,
rect->x+rect->width, rect->y
};
BOOL segmentStrokes[3] = {
TRUE, TRUE, TRUE
};
// Create a closed geometry figure using the three
// segments defined above.
hr = xpsFactory->CreateGeometryFigure( &startPoint, &rectFigure );
hr = rectFigure->SetIsClosed( TRUE );
hr = rectFigure->SetIsFilled( TRUE );
hr = rectFigure->SetSegments( 3, 6,
segmentTypes, segmentData, segmentStrokes );
// Create a geometry that consists of the figure created above.
hr = xpsFactory->CreateGeometry( &imageRectGeometry );
hr = imageRectGeometry->GetFigures( &geomFigureCollection );
hr = geomFigureCollection->Append( rectFigure );
// Create the path that consists of the geometry created above
// and return the pointer in the parameter passed in to the function.
hr = xpsFactory->CreatePath( reinterpret_cast<IXpsOMPath**>(rectPath) );
hr = (*rectPath)->SetGeometryLocal( imageRectGeometry );
// The calling method will release these interfaces when
// it is done with them.
return hr;
}
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