IXpsOMLinearGradientBrush interface

Статья
06/01/2017

Specifies a linear gradient, which is the color gradient along a vector.

When to implement

Never. Custom implementation of this interface is not supported.

Members

The IXpsOMLinearGradientBrush interface inherits from IXpsOMGradientBrush. IXpsOMLinearGradientBrush also has these types of members:

Methods

Methods

The IXpsOMLinearGradientBrush interface has these methods.

Method	Description
Clone	Makes a deep copy of the interface.
GetEndPoint	Gets the end point of the gradient.
GetStartPoint	Gets the start point of the gradient.
SetEndPoint	Sets the end point of the gradient.
SetStartPoint	Sets the start point of the gradient.

Remarks

In the illustration that follows, the start and end points of a linear gradient are also the start and end points of the gradient path, which is the straight line that connects those points.

The gradient region of a linear gradient is the area between and including the start and end points and extending in both directions at a right angle to the gradient path. The spread area is the area of the geometry that lies outside the gradient region.

Gradient stops are used to define the color at specific locations along the gradient path. In the illustration, gradient stop 0 is located at the start point of the gradient path, and gradient stop 1 is at the end point. The XPS_SPREAD_METHOD_PAD spread method is used to fill the spread area.

A figure that shows the terms used in a linear gradient

The code example that follows illustrates how to create an instance of this interface.

IXpsOMLinearGradientBrush    *newInterface;
// The following values are defined outside of 
// this example.
//  IXpsOMGradientStop       *gradStop1, *gradStop2;
//  XPS_POINT                startPoint, endPoint;

// Note the implicit requirement that CoInitializeEx 
//  has previously been called from this thread.

hr = CoCreateInstance(
    __uuidof(XpsOMObjectFactory),
    NULL,
    CLSCTX_INPROC_SERVER,
    _uuidof(IXpsOMObjectFactory),
    reinterpret_cast<LPVOID*>(&xpsFactory)
    );

if (SUCCEEDED(hr))
{
    hr = xpsFactory->CreateLinearGradientBrush (
        gradStop1,
        gradStop2,
        &startPoint,
        &endPoint,
        &newInterface);

    if (SUCCEEDED(hr))
    {
        // use newInterface

        newInterface->Release();
    }
    xpsFactory->Release();
}
else
{
    // evaluate HRESULT error returned in hr
}

Requirements

Minimum supported client	Windows 7, Windows Vista with SP2 and Platform Update for Windows Vista [desktop apps \| Windows Store apps]
Minimum supported server	Windows Server 2008 R2, Windows Server 2008 with SP2 and Platform Update for Windows Server 2008 [desktop apps \| Windows Store apps]
Header	Xpsobjectmodel.h
IDL	XpsObjectModel.idl

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