描述

 

获取此路径渐变画笔的中心点.

 

C++ Syntax

 

 

 

FreeBASIC 语法

 

 

 

参数

 

pt

 

[out]指向PointF或Point结构接收中心点.

 

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.

 

备注

 

默认情况下,一个PathGradientBrush对象的中心点是在刷的边界路径的中心,但是你可以设置中心点到任何位置,路径的内部或外部,通过调用对象的方法的PathGradientBrush SetCenterPoint.

 

引用文件

 

CGpBrush.inc (include CGdiPlus.inc)

 

示例

 

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

' The following example demonstrates several methods of the PathGradientBrush class including

' PathGradientBrush.GetCenterPoint and PathGradientBrush.SetCenterColor. The code creates

' a PathGradientBrush object and then sets the brush's center color and boundary color.

' The code calls the PathGradientBrush.GetCenterPoint method to determine the center point

' of the path gradient and then draws a line from the origin to that center point.

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

SUB Example_GetCenterPoint (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)

 

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

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

 

  ' // Obtain information about the path gradient brush.

  DIM centerPoint AS GpPointF

  pthGrBrush.GetCenterPoint(@centerPoint)

 

  ' // Draw a line from the origin to the center of the ellipse.

  DIM pen AS CGpPen = GDIP_ARGB(255, 0, 255, 0)

  DIM pt AS GpPointF = GDIP_POINTF(0, 0)

  graphics.DrawLine(@pen, @pt, @centerPoint)

 

END SUB

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