不能讓GridBagLayout按需要工作

/** 
* I'd like to achive following layout: 
* +----------+----------+ 
* | Button 1 |   | 
* +----------| Button 2 | 
* | Button 3 |   | 
* +----------+----------+ 
* with following code: 
*/ 

JPanel panel = new JPanel(new GridBagLayout()); 
GridBagConstraints c = new GridBagConstraints(); 
JButton button; 

button = new JButton("Button 1"); 
c.weightx = 0.5; 
c.weighty = 0.5; 
c.fill = GridBagConstraints.BOTH; 
panel.add(button, c); 

button = new JButton("Button 2"); 
c.gridwidth = GridBagConstraints.REMAINDER; 
c.gridheight = 2; 
panel.add(button, c); 

button = new JButton("Button 3"); 
c.gridwidth = 1; 
panel.add(button, c); 

/** 
* but what I achive is: 
* +----------+----------+ 
* | Button 1 | Button 2 | 
* +----------+----------+| 
* | Button 3 | 
* +----------+ 
*/ 

/** 
* However layout: 
* +----------+----------+ 
* |   | Button 2 | 
* + Button 1 +----------+ 
* |   | Button 3 | 
* +----------+----------+ 
* is easily achieved as: 
*/ 

JPanel panel = new JPanel(new GridBagLayout()); 
GridBagConstraints c = new GridBagConstraints(); 
JButton button; 

button = new JButton("Button 1"); 
c.weightx = 0.5; 
c.weighty = 0.5; 
c.fill = GridBagConstraints.BOTH; 
c.gridheight = 2; 
panel.add(button, c); 

button = new JButton("Button 2"); 
c.gridwidth = GridBagConstraints.REMAINDER; 
c.gridheight = 1; 
panel.add(button, c); 

button = new JButton("Button 3"); 
panel.add(button, c);

任何線索？不能讓GridBagLayout按需要工作

關於法國sc

來源

2010-12-05 francesc

您需要在約束上設置gridx和gridy。查看本教程：http://download.oracle.com/javase/tutorial/uiswing/layout/gridbag.html

來源

2010-12-05 12:11:31 Freddie

您尚未爲元素指定gridx和gridy設置。

JPanel panel = new JPanel(new GridBagLayout()); 
GridBagConstraints c = new GridBagConstraints(); 
JButton button; 

button = new JButton("Button 1"); 
c.weightx = 0.5; 
c.weighty = 0.5; 
c.fill = GridBagConstraints.BOTH; 
c.gridx = 0; 
c.gridy = 0; 
panel.add(button, c); 

button = new JButton("Button 2"); 
c.gridwidth = GridBagConstraints.REMAINDER; 
c.gridheight = 2; 
c.gridx = 1; 
c.gridy = 0; 
panel.add(button, c); 

button = new JButton("Button 3"); 
c.gridwidth = 1; 
c.gridx = 0; 
c.gridy = 1; 
panel.add(button, c);

注意：gridx和gridy的默認值爲0，但最好總是設置該值。它更清晰，依靠默認值可能會在複製和粘貼等時造成問題。因此，這種方式更清晰，更安全（儘管略爲冗長）。

來源

2010-12-05 12:12:05 Codemwnci

不工作，結果與我的一樣，你試過了嗎？ – francesc 2010-12-05 12:56:56

的GridBagLayout是knowln是diffficul（見http://www.horstmann.com/articles/Taming_the_GridBagLayout.html）：

的的Java SDK的標準佈局管理器時，GridBagLayout的是最有用的，但它的複雜性也已經知道在中打擊恐懼程序員的心。部分的複雜性在於設置網格包約束的單調乏味。

我會讀這些文章，也請在論壇上（例如http://www.java-forums.org/new-java/28857-gridbaglayout-problems-questions.html）

來源

2010-12-05 12:12:52

你需要指定的gridx和gridy，默認值是0。

button = new JButton("Button 1"); 
    c.weightx = 0.5; 
    c.weighty = 0.5; 
    c.fill = GridBagConstraints.BOTH; 
    panel.add(button, c); 

    button = new JButton("Button 3"); 
    c.gridy = 1; 
    c.gridwidth = 1; 
    panel.add(button, c); 

    button = new JButton("Button 2"); 
    c.gridx = 1; c.gridy = 0; 
    c.gridwidth = GridBagConstraints.REMAINDER; 
    c.weighty = 1;c.gridheight = 2; 
    panel.add(button, c);

來源

2010-12-05 12:14:48 albb

您必須爲最後一個按鈕設置c.gridx。默認情況下，組件相對於彼此放置。如果將按鈕3的gridx設置爲0，則強制將其置於第一列。

JPanel panel = new JPanel(new GridBagLayout()); 
GridBagConstraints c = new GridBagConstraints(); 
JButton button; 

button = new JButton("Button 1"); 
c.weightx = 1; 
c.weighty = 1; 
c.fill = GridBagConstraints.BOTH; 
panel.add(button, c); 

button = new JButton("Button 2"); 
c.gridwidth = GridBagConstraints.REMAINDER; 
c.gridheight = GridBagConstraints.REMAINDER;   
panel.add(button, c); 

button = new JButton("Button 3"); 
c.gridx = 0; 
c.gridwidth = 1; 
c.gridheight = 1; 
panel.add(button, c);

來源

2010-12-05 12:17:00 Sofahamster

好吧，你的代碼工作，但由於按鈕2有c.gridwidth = GridBagConstraints.REMAINDER;按鈕3 shoukd開始一個新行，這是第一列，不需要指定它 – francesc 2010-12-05 17:37:15

爲什麼不改用使用GridLayouts嵌套JPanels，如：

import java.awt.GridLayout; 
import javax.swing.*; 

public class GridLayoutEg { 
    public static void main(String[] args) { 
     JPanel leftPanel = new JPanel(new GridLayout(0, 1)); 
     leftPanel.add(new JButton("Button 1")); 
     leftPanel.add(new JButton("Button 3")); 

     JPanel mainPanel = new JPanel(new GridLayout(1, 0)); 
     mainPanel.add(leftPanel); 
     mainPanel.add(new JButton("Button 2")); 

     JFrame frame = new JFrame("Foo"); 
     frame.getContentPane().add(mainPanel); 
     frame.pack(); 
     frame.setLocationRelativeTo(null); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.setVisible(true); 
    } 
}

還是有更多的，我們需要知道這個故事？

來源

2010-12-05 12:17:15

是的，其他人都是對的。您必須手動設置GridX和GridY。此外，我建議爲每個組件使用一個新的GridBagConstraints實例，因爲在更復雜的形式中，您可以輕鬆地跟蹤您正在使用的實例中設置的值。另外，如果使用具有多個參數的構造函數，則不必關心默認值，因爲每次都必須指定它們。習慣它需要一定的時間，但稍後會回報。

 

    /** 
    * +----------+----------+ 
    * | Button 1 |   | 
    * +----------| Button 2 | 
    * | Button 3 |   | 
    * +----------+----------+ 
    */ 

    JPanel panel = new JPanel(new GridBagLayout()); 

    JButton b1 = new JButton("Button 1"); 
    panel.add(b1, new GridBagConstraints(0, 0, 1, 1, 0.0, 0.0, 
     GridBagConstraints.CENTER, GridBagConstraints.BOTH, new Insets(0, 0, 0, 
      0), 0, 0)); 

    JButton b2 = new JButton("Button 2"); 
    panel.add(b2, new GridBagConstraints(1, 0, 1, 2, 0.0, 0.0, 
     GridBagConstraints.CENTER, GridBagConstraints.BOTH, new Insets(0, 0, 0, 
      0), 0, 0)); 

    JButton b3 = new JButton("Button 3"); 
    panel.add(b3, new GridBagConstraints(0, 1, 1, 1, 0.0, 0.0, 
     GridBagConstraints.CENTER, GridBagConstraints.BOTH, new Insets(0, 0, 0, 
      0), 0, 0));

來源

2010-12-05 12:20:10

不能讓GridBagLayout按需要工作

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