RectangleF.Union(RectangleF, RectangleF) 方法

public:
 static System::Drawing::RectangleF Union(System::Drawing::RectangleF a, System::Drawing::RectangleF b);

public static System.Drawing.RectangleF Union(System.Drawing.RectangleF a, System.Drawing.RectangleF b);

static member Union : System.Drawing.RectangleF * System.Drawing.RectangleF -> System.Drawing.RectangleF

Public Shared Function Union (a As RectangleF, b As RectangleF) As RectangleF

参数

返回

第三 RectangleF 个结构，包含构成联合的两个矩形中的两个。

示例

此示例设计用于 Windows 窗体，它需要 PaintEventArgs e，OnPaint 事件对象。 该代码创建两 RectangleF 个 s，并用黑色和红色将其绘制到屏幕。 请注意，出于绘图目的，它们必须转换为 Rectangle s。 然后，代码使用RectangleF该方法创建第三Union个代码，将其转换为 aRectangle，并将其绘制为蓝色屏幕。 请注意，第三个（蓝色）矩形是可以包含其他两个矩形的最小矩形：

public:
   void RectangleFUnionExample( PaintEventArgs^ e )
   {
      // Create two rectangles and draw them to the screen.
      RectangleF firstRectangleF = RectangleF(0,0,75,50);
      RectangleF secondRectangleF = RectangleF(100,100,20,20);

      // Convert the RectangleF structures to Rectangle structures and draw them to the
      // screen.
      Rectangle firstRect = Rectangle::Truncate( firstRectangleF );
      Rectangle secondRect = Rectangle::Truncate( secondRectangleF );
      e->Graphics->DrawRectangle( Pens::Black, firstRect );
      e->Graphics->DrawRectangle( Pens::Red, secondRect );

      // Get the union rectangle.
      RectangleF unionRectangleF = RectangleF::Union( firstRectangleF, secondRectangleF );

      // Draw the unionRectangleF to the screen.
      Rectangle unionRect = Rectangle::Truncate( unionRectangleF );
      e->Graphics->DrawRectangle( Pens::Blue, unionRect );
   }

public void RectangleFUnionExample(PaintEventArgs e)
{
             
    // Create two rectangles and draw them to the screen.
    RectangleF firstRectangleF = new RectangleF(0, 0, 75, 50);
    RectangleF secondRectangleF = new RectangleF(100, 100, 20, 20);
             
    // Convert the RectangleF structures to Rectangle structures and draw them to the
             
    // screen.
    Rectangle firstRect = Rectangle.Truncate(firstRectangleF);
    Rectangle secondRect = Rectangle.Truncate(secondRectangleF);
    e.Graphics.DrawRectangle(Pens.Black, firstRect);
    e.Graphics.DrawRectangle(Pens.Red, secondRect);
             
    // Get the union rectangle.
    RectangleF unionRectangleF = RectangleF.Union(firstRectangleF,
        secondRectangleF);
             
    // Draw the unionRectangleF to the screen.
    Rectangle unionRect = Rectangle.Truncate(unionRectangleF);
    e.Graphics.DrawRectangle(Pens.Blue, unionRect);
}

Public Sub RectangleFUnionExample(ByVal e As PaintEventArgs)

    ' Create two rectangles and draw them to the screen.
    Dim firstRectangleF As New RectangleF(0, 0, 75, 50)
    Dim secondRectangleF As New RectangleF(100, 100, 20, 20)

    ' Convert the RectangleF structures to Rectangle structures and

    ' draw them to the screen.
    Dim firstRect As Rectangle = Rectangle.Truncate(firstRectangleF)
    Dim secondRect As Rectangle = Rectangle.Truncate(secondRectangleF)
    e.Graphics.DrawRectangle(Pens.Black, firstRect)
    e.Graphics.DrawRectangle(Pens.Red, secondRect)

    ' Get the union rectangle.
    Dim unionRectangleF As RectangleF = _
    RectangleF.Union(firstRectangleF, secondRectangleF)

    ' Draw the unionRectangleF to the screen.
    Dim unionRect As Rectangle = Rectangle.Truncate(unionRectangleF)
    e.Graphics.DrawRectangle(Pens.Blue, unionRect)
End Sub

注解

当两个矩形中的一个为空，这意味着其所有值均为零时， Union 该方法返回一个起点为 （0， 0） 的矩形，以及非空矩形的高度和宽度。 例如，如果你有两个矩形 A = （0， 0; 0， 0） 和 B = （1， 1; 2， 2），则 A 和 B 的并集为 （0， 0; 2， 2）。