描述

 

获取定义渐变边界的矩形.

 

C++ Syntax

 

 

FreeBASIC 语法

 

 

参数

 

rc

 

[out]指针指向一个结构,RectF接收定义梯度的边界矩形.例如,如果一个线性渐变画笔与起始点和终结点(20.2, 50.8)在(60.5, 110.0),然后定义矩形的左上点(20.2, 50.8),宽度和高度59.2.构建40.3,

 

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

 

矩形定义的梯度的边界在以下几个方面：对矩形形式的水平梯度的边界左边；顶部和底部形成一个垂直梯度的边界；两对角相对的角落位于对角线梯度的边界.在每一种情况下,任一边/角可能位于起始边界上,这取决于起始点和结束点是如何传递给构造函数的.

 

引用文件

 

CGpBrush.inc (include CGdiPlus.inc)

 

示例

 

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

' The following example creates a linear gradient brush. Then the code gets the brush's

' rectangle and draws it.

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

SUB Example_GetRectangle (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 linear gradient brush.

  DIM pt1 AS GpPoint = GDIP_POINT(20, 10)

  DIM pt2 AS GpPoint = GDIP_POINT(60, 110)

  DIM linGrBrush AS CGpLinearGradientBrush = CGpLinearGradientBrush(@pt1, @pt2, _

     GDIP_ARGB(255, 0, 0, 0), GDIP_ARGB(255, 0, 0, 255))

 

  ' // Obtain information about the linear gradient brush.

  DIM rc AS GpRect

  linGrBrush.GetRectangle(@rc)

 

  ' // Draw the retrieved rectangle.

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

  graphics.DrawRectangle(@pen, @rc)

 

END SUB

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