描述

 

设置此路径渐变画笔的混合因子和混合位置.

 

C++ Syntax

 

 

FreeBASIC 语法

 

 

参数

 

blendFactors

 

[in]混合因子数组指针.数组中的每个数字应该在0到1的范围内.

 

blendPositions

 

[in]混合位置指针数组.数组中的每个数字应该在0到1的范围内.

 

nCount

 

[in]整数,指定在blendFactors数组元素个数.这是因为在blendPositions数组的元素个数.

 

返回值

 

如果该方法成功,则返回Ok,这是对Status枚举元素.

如果这个方法失败,它返回一个枚举的其他元素的Status.

 

备注

 

一个PathGradientBrush对象有一个边界路径和中心点.当你用路径渐变笔刷填充一个区域时,当你从边界路径移动到中心点时,颜色会逐渐改变.默认情况下,色彩的距离成线性关系,但可以通过调用PathGradientBrush.SetBlend方法自定义颜色和距离之间的关系.

 

引用文件

 

CGpBrush.inc (include CGdiPlus.inc)

 

示例

 

' ========================================================================================

' The following example creates a PathGradientBrush object based on an ellipse. The code

' calls the PathGradientBrush::SetBlend method of the PathGradientBrush object to establish

' a set of blend factors and blend positions for the brush. Then the code uses the path

' gradient brush to fill the ellipse.

' ========================================================================================

SUB Example_SetBlend (BYVAL hdc AS HDC)

 

  ' // Create a graphics object from the window device context

  DIM graphics AS CGpGraphics = hdc

  ' // Get the DPI scaling ratio

  DIM rxRatio AS SINGLE = graphics.GetDpiX / 96

  DIM ryRatio AS SINGLE = graphics.GetDpiY / 96

  ' // Set the scale transform

  graphics.ScaleTransform(rxRatio, ryRatio)

 

  ' // Create a path that consists of a single ellipse.

  DIM path AS CGpGraphicsPath

  path.AddEllipse(0, 0, 200, 100)

 

  ' // Use the path to construct a brush.

  DIM pthGrBrush AS CGpPathGradientBrush = @path

 

  ' // Set the color at the center of the path to blue.

  pthGrBrush.SetCenterColor(GDIP_ARGB(255, 0, 0, 255))

 

  ' // Set the color along the entire boundary of the path to aqua.

  DIM colors(0) AS ARGB = {GDIP_ARGB(255, 0, 255, 255)}

  DIM count AS LONG = 1

  pthGrBrush.SetSurroundColors(@colors(0), @count)

 

  ' // Set blend factors and positions for the path gradient brush.

  DIM factors(0 TO 3) AS SINGLE = {0.0, 0.4, 0.8, 1.0}

  DIM positions(0 TO 3) AS SINGLE = {0.0, 0.3, 0.7, 1.0}

 

  pthGrBrush.SetBlend(@factors(0), @positions(0), 4)

 

  ' // Fill the ellipse with the path gradient brush.

  graphics.FillEllipse(@pthGrBrush, 0, 0, 200, 100)

 

END SUB

' ========================================================================================