描述

 

获取当前为此路径渐变刷设置的混合因子和相应的混合位置.

 

C++ Syntax

 

 

FreeBASIC 语法

 

 

参数

 

blendFactors

 

[out]数组指针接收混合因子.

 

blendPositions

 

[out]数组指针接收混合位置.

 

count

 

[in]整数,指定要检索的混合因子数.调用一个对象的PathGradientBrush.GetBlend PathGradientBrush方法之前,调用同一PathGradientBrush对象的PathGradientBrush.GetBlendCount方法来确定当前的混合因子数.检索的混合位置的数目是相同的检索的混合因子的数目.

 

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 demonstrates several methods of the PathGradientBrush class including

' PathGradientBrush.SetBlend, PathGradientBrush.GetBlendCount, and PathGradientBrush.GetBlend.

' The code creates a PathGradientBrush object and calls the PathGradientBrush.SetBlend method

' to establish a set of blend factors and blend positions for the brush. Then the code calls

' the PathGradientBrush.GetBlendCount method to retrieve the number of blend factors. After

' the number of blend factors is retrieved, the code allocates two buffers: one to receive

' the array of blend factors and one to receive the array of blend positions. Then the code

' calls the PathGradientBrush.GetBlend method to retrieve the blend factors and the blend

' positions.

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

SUB Example_GetBlend (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)

 

  ' // Obtain information about the path gradient brush.

  DIM blendCount AS LONG = pthGrBrush.GetBlendCount

  DIM rgFactors(blendCount - 1) AS SINGLE

  DIM rgPositions(blendCount - 1) AS SINGLE

 

  pthGrBrush.GetBlend(@rgFactors(0), @rgPositions(0), blendCount)

 

  FOR j AS LONG = 0 TO blendCount - 1

'      // Inspect or use the value in rgFactors(j)

'      // Inspect or use the value in rgPositions(j)

     OutputDebugString STR(rgFactors(j)) & STR(rgPositions(j))

  NEXT

 

END SUB

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