Java AWT GridLayout用法及代碼示例

GridLayout 類表示在矩形網格中具有指定行數和列數的布局管理器。 GridLayout 容器被分成 equal-sized 矩形，每個矩形中放置一個組件。每個矩形單元格具有相同的大小，因此它們包含一個填充整個單元格的組件。當用戶改變或調整容器的大小時，每個矩形的大小也會相應改變。

類的構造函數：

1. GridLayout():它創建一個網格布局，默認情況下每個組件一列，在一行中。
2. GridLayout(int rw，int cl)：它創建具有指定行數和列數的網格布局。
3. GridLayout(int rw，int cl，int hgap，int vgap)：它創建具有指定行數和列數以及水平和垂直間隙的網格布局。

常用方法：

• addLayoutComponent(字符串str，組件cmp)：將具有指定名稱的指定組件添加到布局中。
• setColumns(int cl):將此布局中的列數設置為指定值。
• setHgap(int hgap)：將組件之間的水平間隙設置為指定值。
• setRows(int rw):將此布局中的行數設置為指定值。
• setVgap(int vgap)：將組件之間的垂直間隙設置為指定值。
• 布局容器(容器pr)：使用此布局布置指定容器。
• toString():返回此網格布局值的字符串表示形式。

以下示例程序旨在說明 GridLayout 類：

• 程序1:在下麵的程序中，我們將參數傳遞給GridLayout。我們創造 4J標簽名為“的組件一“，”二“，”三“，”四”並創建 2J按鈕名為“的組件按鈕保存“ 和 ”按鈕退出”並創建 4文本字段名為“的組件名稱“，”代碼“，”設計“，”查拉裏”並將它們全部添加到J框架通過方法add()。我們將使用以下方法設置框架的可見性和大小setVisible()和setSize()方法。布局是通過使用設置的setLayout()方法。

  
  // Java program to illustrate the GridLayout 
  import javax.swing.*; 
  import java.awt.*; 
    
  // class GridLayout extends JFrame 
  public class GridLayoutDemo extends JFrame { 
    
  GridLayoutDemo() { 
    
      // Creating Object P1 of JPanel class 
      JPanel p1 = new JPanel(); 
    
      // set the layout 
      p1.setLayout(new GridLayout(4, 2)); 
    
      // Creating Object of "FlowLayout" class 
      FlowLayout layout = new FlowLayout(); 
    
      // Creating Object P2 of JPanel class 
      JPanel p2 = new JPanel(); 
    
      // set the layout 
      p2.setLayout(layout); 
    
      // Declaration of objects of JLabel class. 
      JLabel one, two, three, four; 
    
      // Declaration of objects of JTextField class. 
      JTextField tname, tsalary, tcode, tdesig; 
    
      // Declaration of objects of JButton class. 
      JButton buttonSave, buttonExit; 
    
      // Initialization of object  
      // "one" of JLabel class. 
      one = new JLabel("NAME"); 
    
      // Initialization of object  
      // "tname" of JTextField class. 
      tname = new JTextField(20); 
    
      // Initialization of object 
      // "two" of JLabel class. 
      two = new JLabel("CODE"); 
    
      // Initialization of object  
      // "tcode" of JTextField class. 
      tcode = new JTextField(20); 
    
      // Initialization of object 
      // "three" of JLabel class. 
      three = new JLabel("DESIGNATION"); 
    
      // Initialization of object  
      // "tdesig" of JTextField class. 
      tdesig = new JTextField(20); 
    
      // Initialization of object 
      // "four" of JLabel class. 
      four = new JLabel("SALARY"); 
    
      // Initialization of object  
      // "tsalary" of JTextField class. 
      tsalary = new JTextField(20); 
    
      // Initialization of object 
      // "buttonsave" of JButton class. 
      buttonSave = new JButton("SAVE"); 
    
      // Initialization of object 
      // "buttonexit" of JButton class. 
      buttonExit = new JButton("EXIT"); 
    
      // Adding Jlabel "one" on JFrame. 
      p1.add(one); 
    
      // Adding JTextField "tname" on JFrame. 
      p1.add(tname); 
    
      // Adding Jlabel "two" on JFrame. 
      p1.add(two); 
    
      // Adding JTextField "tcode" on JFrame. 
      p1.add(tcode); 
    
      // Adding Jlabel "three" on JFrame. 
      p1.add(three); 
    
      // Adding JTextField "tdesig" on JFrame. 
      p1.add(tdesig); 
    
      // Adding Jlabel "four" on JFrame. 
      p1.add(four); 
    
      // Adding JTextField "tsalary" on JFrame. 
      p1.add(tsalary); 
    
      // Adding JButton "buttonsave" on JFrame. 
      p2.add(buttonSave); 
    
      // Adding JButton "buttonexit" on JFrame. 
      p2.add(buttonExit); 
    
      // add the p1 object which  
      // refer to the Jpanel 
      add(p1, "North"); 
    
      // add the p2 object which 
      // refer to the Jpanel 
      add(p2, "South"); 
    
      // Function to set visible 
      // status of JFrame. 
      setVisible(true); 
    
      // this Keyword refers to current 
      // object. Function to set size of JFrame. 
      this.setSize(400, 180); 
  } 
    
      // Main Method 
      public static void main(String args[]) 
      { 
    
          // calling the constructor 
          new GridLayoutDemo(); 
      } 
  } 

  輸出：
• 程序2:在下麵的程序中，我們將參數傳遞給GridLayout。我們創造了5個J按鈕名為“的組件按鈕1“，”按鈕2“，”按鈕3“，”按鈕4“，”按鈕5”，然後將它們添加到J框架通過方法add()。我們將使用以下方法設置框架的可見性和大小setvisible()和setsize()方法。布局是通過使用設置的setLayout()方法。

  
  // Java program to illustrate the GridLayout 
  import java.awt.*; 
  import javax.swing.*; 
    
  // create a class griddemo 
  public class Griddemo { 
    
  // Main Method 
  public static void main(String[] args) 
  { 
    
      // Creating Object of JFrame class  
      // with new name frame 
      JFrame frame = new JFrame("GridLayout Demo"); 
    
      // Initialization of object  
      // "btn1" of JButton class. 
      JButton btn1 = new JButton("Button 1"); 
    
      // Initialization of object  
      // "btn2" of JButton class. 
      JButton btn2 = new JButton("Button 2"); 
    
      // Initialization of object  
      // "btn3" of JButton class. 
      JButton btn3 = new JButton("Button 3"); 
    
      // Initialization of object 
      // "btn4" of JButton class. 
      JButton btn4 = new JButton("Button 4"); 
    
      // Initialization of object  
      // "btn5" of JButton class. 
      JButton btn5 = new JButton("Button 5"); 
    
      // Creating Object Panel of JPanel class 
      // create grid layout with 3 rows,  
      // 2 columns with horizontal and  
      // vertical gap set to 10 
      JPanel panel = new JPanel(new GridLayout(3, 2, 10, 10)); 
    
      // Adding JButton "btn1" on JPanel. 
      panel.add(btn1); 
    
      // Adding JButton "btn2" on JPanel. 
      panel.add(btn2); 
    
      // Adding JButton "btn3" on JPanel. 
      panel.add(btn3); 
    
      // Adding JButton "btn4" on JPanel. 
      panel.add(btn4); 
    
      // Adding JButton "btn5" on JPanel. 
      panel.add(btn5); 
    
      // Function to close the operation of JFrame. 
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
    
      // Function to set size of JFrame. 
      frame.setSize(300, 150); 
    
      // Function to get the content of JFrame. 
      frame.getContentPane().add(panel); 
    
      // Function to set visible status of JFrame. 
      frame.setVisible(true); 
  } 
  } 

  輸出：

注意：上述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/7/docs/api/java/awt/GridLayout.html