JavaFX 類 Rectangle2D用法及代碼示例

Rectangle2D類是JavaFX的一部分。 Rectangle2D類使用給定的矩形左上角坐標，寬度和高度來創建一個矩形，或者由位置(minX，minY)和尺寸(寬度x高度)定義該矩形。

該類的構造函數：

• Rectangle2D(double minX, double minY, double width, double height)：創建具有指定寬度高度和Rectangle左上角坐標的新Rectangle2D

常用方法：

方法	說明
contains(double x, double y)	檢查指定的坐標是否在Rectangle2D的邊界內。
contains(double x, double y, double w, double h)	檢查指定的矩形是否位於給定的矩形內
contains(Point2D p)	檢查指定的Point2D坐標是否在Rectangle2D的邊界內。
contains(Rectangle2D r)	檢查指定的Rectangle2D是否位於給定的矩形內
getHeight()	返回矩形的高度
getWidth()	返回矩形的寬度
getMaxX()	此Rectangle2D右下角的x坐標。
getMinX()	此Rectangle2D左上角的x坐標。
getMaxY()	此Rectangle2D右下角的y坐標。
getMinY()	此Rectangle2D左上角的y坐標。
intersects(double x, double y, double w, double h)	檢查指定的矩形是否與Rectangle2D對象相交
intersects(Rectangle2D r)	檢查指定的Rectangle2D(r)是否與Rectangle2D對象相交

以下示例程序旨在說明Rectangle2D類的用法：

1. Java程序，用於創建Rectangle2D對象並顯示其詳細信息以及它是否包含點並檢查其是否與矩形相交：該程序使用minX，minY，height和width作為參數創建一個名為Rectangle2D的對象矩形。使用顯示函數顯示Rectangle2D對象的詳細信息。顯示函數使用getMinX()，getMinY()，getMaxX()，getMaxY()，getHeight()和getWidth()來顯示矩形的左上坐標和矩形的右下角及其寬度和高度。我們將使用contains()函數查看矩形是否包含點，並使用相交函數檢查矩形是否與另一個矩形相交並顯示結果。

   // Java Program to create an object of  
   // Rectangle2D and display its details 
   // and whether it contains a point and  
   // whether it intersects a rectangle or not 
   import javafx.geometry.*; 
   import java.util.*; 
     
   class Rectangle_1 { 
         
       // Main Method 
       public static void main(String args[]) 
       { 
           try { 
                 
               // rectangle object 
               Rectangle2D rectangle = new Rectangle2D(100, 100,  
                                                      100, 100); 
     
               // display the rectangle 
               display(rectangle); 
     
               // Check whether the rectangle contains a point 
               System.out.println("The rectangle contains point 150, 150 = " 
                               + rectangle.contains(new Point2D(150, 150))); 
                                 
               System.out.println("The rectangle contains point 50, 50 = " 
                              + rectangle.contains(new Point2D(50, 50))); 
     
               // Check Whether the rectangle  
               // intersects another rectangle 
               System.out.print("The rectangle intersects another rectangle " 
                  +"with width = 100, height = 100, minX = 50, & minY = 50:" 
                                   + rectangle.intersects(50, 50, 100, 100)); 
           } 
             
           catch (Exception e)  
           { 
               System.err.println(e.getMessage()); 
           } 
       } 
     
       // display function 
       public static void display(Rectangle2D rectangle) 
       { 
             
           // display the details of a rectangle 
           System.out.println("Upper left point of the rectangle is = " 
                    + rectangle.getMinX() + ", " + rectangle.getMinY()); 
                    
           System.out.println("Lower right point of the rectangle is = " 
                    + rectangle.getMaxX() + ", " + rectangle.getMaxY()); 
                    
           System.out.println("Width and Height of the rectangle is = " 
                 + rectangle.getWidth() + ", " + rectangle.getHeight()); 
       } 
   }

   輸出：

   Upper left point of the rectangle is = 100.0, 100.0
   Lower right point of the rectangle is = 200.0, 200.0
   Width and Height of the rectangle is = 100.0, 100.0
   The rectangle contains point 150, 150 = true
   The rectangle contains point 50, 50 = false
   The rectangle intersects another rectangle with width = 100, height = 100, minX = 50, & minY = 50:true

2. Java程序創建兩個Rectangle2D對象並顯示其詳細信息，並檢查其是否相交：該程序將使用minX，minY，height和width作為參數創建兩個名為Rectangle_1和Rectangle_2的Rectangle2D對象。使用顯示函數顯示Rectangle2D對象的詳細信息。顯示函數使用getMinX()，getMinY()，getMaxX()，getMaxY()，getHeight()和getWidth()來顯示矩形的左上坐標和矩形的右下角及其寬度和高度。我們將使用相交函數檢查它是否與另一個矩形相交並顯示結果。

   // Java Program to create two objects of 
   // Rectangle2D and display its details and 
   // check whether it intersects each other or not 
   import javafx.geometry.*; 
   import java.util.*; 
     
   class Rectangle_1 { 
         
       // Main Method 
       public static void main(String args[]) 
       { 
           try 
           { 
                 
               // rectangle object 
               Rectangle2D rectangle_1 = new Rectangle2D(100, 100, 
                                                        100, 100); 
                                                          
               Rectangle2D rectangle_2 = new Rectangle2D(100, 100, 
                                                        100, 100); 
     
               // display the rectangle details 
               System.out.println("Rectangle_1 details"); 
               display(rectangle_1); 
                  
                           System.out.println(""); 
                 
               System.out.println("Rectangle_2 details"); 
               display(rectangle_2); 
     
               // display whether these two  
               // rectangle intersects or not 
               System.out.println("These two rectangles intersect = " 
                              + rectangle_1.intersects(rectangle_2)); 
           } 
             
           catch (Exception e) { 
               System.err.println(e.getMessage()); 
           } 
       } 
     
       // display method 
       public static void display(Rectangle2D r) 
       { 
             
           // display the details of a rectangle 
           System.out.println("Upper left point of the rectangle is = " 
                                    + r.getMinX() + ", " + r.getMinY()); 
                                      
           System.out.println("Lower right point of the rectangle is = " 
                                     + r.getMaxX() + ", " + r.getMaxY()); 
                                       
           System.out.println("Width and Height of the rectangle is = " 
                                 + r.getWidth() + ", " + r.getHeight()); 
       } 
   }

   輸出：

   Rectangle_1 details
   Upper left point of the rectangle is = 100.0, 100.0
   Lower right point of the rectangle is = 200.0, 200.0
   Width and Height of the rectangle is = 100.0, 100.0

   Rectangle_2 details
   Upper left point of the rectangle is = 100.0, 100.0
   Lower right point of the rectangle is = 200.0, 200.0
   Width and Height of the rectangle is = 100.0, 100.0
   These two rectangles intersect = true

注意：以上程序可能無法在在線IDE中運行。請使用離線編譯器。

參考： https://docs.oracle.com/javase/8/javafx/api/javafx/geometry/Rectangle2D.html