描述

 

设置此路径渐变画笔的中心点.默认情况下,中心点位于画笔边界路径的中心位置,但可以将中心点设置为路径内或外部的任何位置.

 

C++ Syntax

 

 

 

FreeBASIC 语法

 

 

 

参数

 

pt

 

[in]参考一PointF或Point结构指定的中心点.

 

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.

 

引用文件

 

CGpBrush.inc (include CGdiPlus.inc)

 

示例

 

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

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

' sets the center color to blue and sets the color along the boundary to aqua. By default,

' the center point would be at the center of the ellipse (100, 50), but the call to the

' PathGradientBrush.SetCenterPoint method sets the center point to (180.5, 50.0).

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

SUB Example_SetCenterPoint (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 center point.

  DIM pt AS GpPointF = GDIP_POINTF(180.5, 50.0)

  pthGrBrush.SetCenterPoint(@pt)

 

  ' // 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)

 

  graphics.FillRectangle(@pthGrBrush, 0, 0, 300, 300)

 

END SUB

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