IXpsOMObjectFactory::CreateLinearGradientBrush method (xpsobjectmodel.h)

Creates an IXpsOMLinearGradientBrush interface.

Syntax

HRESULT CreateLinearGradientBrush(
  [in]          IXpsOMGradientStop        *gradStop1,
  [in]          IXpsOMGradientStop        *gradStop2,
  [in]          const XPS_POINT           *startPoint,
  [in]          const XPS_POINT           *endPoint,
  [out, retval] IXpsOMLinearGradientBrush **linearGradientBrush
);

Parameters

[in] gradStop1

The IXpsOMGradientStop interface that specifies the gradient properties at the beginning of the gradient's vector. This parameter must not be NULL.

[in] gradStop2

The IXpsOMGradientStop interface that specifies the gradient properties at the end of the gradient's vector. This parameter must not be NULL.

[in] startPoint

The XPS_POINT structure that contains the coordinates of the start point in two-dimensional space.

[in] endPoint

The XPS_POINT structure that contains the coordinates of the end point in two-dimensional space.

[out, retval] linearGradientBrush

A pointer to the new IXpsOMLinearGradientBrush interface.

Return value

The method returns an HRESULT. Possible values include, but are not limited to, those in the table that follows. For information about XPS document API return values that are not listed in this table, see XPS Document Errors.

Remarks

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 define the color at specific locations along the gradient path. In the illustration, gradient stop 0, specified by the gradStop1 parameter, is located at the start point of the gradient path, and gradient stop 1, specified by the gradStop2 parameter, is at the end point.

As shown 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.

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

See also

IXpsOMGradientStop

IXpsOMLinearGradientBrush

IXpsOMObjectFactory

XML Paper Specification

XPS Document Errors

XPS_POINT