IXpsOMRadialGradientBrush interface

Статья
06/01/2017

Specifies a radial gradient.

When to implement

Never. Custom implementation of this interface is not supported.

Members

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

Methods

Methods

The IXpsOMRadialGradientBrush interface has these methods.

Method	Description
Clone	Makes a deep copy of the interface.
GetCenter	Gets the center point of the radial gradient region ellipse.
GetGradientOrigin	Gets the origin point of the radial gradient.
GetRadiiSizes	Gets the sizes of the radii that define the ellipse of the radial gradient region.
SetCenter	Sets the center point of the radial gradient region ellipse.
SetGradientOrigin	Sets the origin point of the radial gradient.
SetRadiiSizes	Sets the sizes of the radii that define ellipse of the radial gradient region.

Remarks

As shown in the figure that follows, the gradient region of a radial gradient is the area enclosed by the ellipse that is described by the center point and the x and y radii that extend from the center point. The spread area is the area outside of that ellipse. The gradient path (not shown) is a radial line that is drawn between the gradient origin and the ellipse that bounds the gradient region.

A figure that shows the terms used in a radial gradient

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

IXpsOMRadialGradientBrush    *newInterface;
// The following values are defined outside of 
// this example.
//  IXpsOMGradientStop       *gradStop1, *gradStop2;
//  XPS_POINT                centerPoint, gradientOrigin;
//  XPS_SIZE                 radiiSizes;

// 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->CreateRadialGradientBrush (
        gradStop1,
        gradStop2,
        &centerPoint,
        &gradientOrigin,
        &radiiSizes,
        &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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