JPanel GridBagLayout

Question

目前，我已經成功實現了使用jpanel的網格袋布局，並添加了7個顯示面板和一些“填充”面板以獲取所需的布局。

現在唯一的問題是這些面板可以更改大小，當它們變得非常大時，它們會影響它們上方/下方或左側/右側的面板，原因是上方/下方，左側/右側的面板共享同一列/行索引，當面板3（參見圖片）超出其默認大小時，上方/下方的面板將受到影響。

當面板只顯示幾個元素時

更常規的設置

很多（不是很經常）系統

這是更新面板的方法。 網格約束分配有很多重復的代碼，我可能應該使一個函數接受這些參數，以使其更具可讀性。

public void updateView() {

    int gridXPos, gridYPos, gridWidth, gridHeight;
    int maxGridWidth = 30;
    Rack r;
    SuctionGroup sg;
    JLabel label;
    JPanel panel;
    GridBagLayout gbl = new GridBagLayout();
    GridBagConstraints c = new GridBagConstraints();

    _Panel_MainPanel.setLayout(gbl);
    _Panel_MainPanel.removeAll();

    // Store panel info at top
    //===========================================================
    // Positioning
    gridXPos = 0;
    gridYPos = 0;
    gridWidth = maxGridWidth;
    gridHeight = 5;
    // Constraints               
    c.fill = GridBagConstraints.BOTH;
    c.weightx = 1;
    c.weighty = 0; // No space between bottom and below row?        
    c.gridx = gridXPos;
    c.gridy = gridYPos;
    c.gridwidth = gridWidth;
    c.gridheight = gridHeight;
    //c.ipady = 100;
    //c.ipady = 0;                
    // End of Constraints
    //===========================================================  
    panel = panelTop(img, storeName);
    _Panel_MainPanel.add(panel, c);

    // Pressure/temp
    //===========================================================
    // Positioning
    gridXPos = 0;
    gridYPos += gridHeight;
    gridWidth = 15;
    gridHeight = 5;
    // Constraints               
    c.fill = GridBagConstraints.BOTH;
    c.weightx = 0;
    c.weighty = 0; // No space between bottom and below row?        
    c.gridx = gridXPos;
    c.gridy = gridYPos;
    c.gridwidth = gridWidth;
    c.gridheight = gridHeight;
    //c.ipady = 100;
    //c.ipady = 0;                
    // End of Constraints
    //=========================================================== 

    panel = panelPressureTemps();
    _Panel_MainPanel.add(panel, c);

    // SEI blank
    //===========================================================
    // Positioning
    gridXPos += gridWidth;
    //gridYPos = gridHeight;  
    gridWidth = 5;
    gridHeight = 5;
    // Constraints               
    c.fill = GridBagConstraints.BOTH;
    c.weightx = 1;
    c.weighty = 0; // No space between bottom and below row?        
    c.gridx = gridXPos;
    c.gridy = gridYPos;
    c.gridwidth = gridWidth;
    c.gridheight = gridHeight;
    //c.ipady = 100;
    //c.ipady = 0;                
    // End of Constraints
    //=========================================================== 
    label = new JLabel("                                              ");
    //label.setBorder(border);
    panel.add(label);

    // performance
    //===========================================================
    // Positioning
    gridXPos += gridWidth;
    //gridYPos += gridHeight;
    gridWidth = 10;
    gridHeight = 10;
    // Constraints               
    //c.fill = GridBagConstraints.BOTH;
    c.weightx = 1;
    c.weighty = 0; // No space between bottom and below row?        
    c.gridx = gridXPos;
    c.gridy = gridYPos;
    c.gridwidth = gridWidth;
    c.gridheight = gridHeight;
    //c.ipady = 100;
    //c.ipady = 0;                
    // End of Constraints
    //=========================================================== 

    panel = panelPerformance();
    _Panel_MainPanel.add(panel, c);

    //=========================================================== 
    // Filler area

    gridYPos += gridHeight;
    gridHeight = 10;
    c.gridx = 0;
    c.gridy = gridYPos;
    c.gridwidth = 20;   
    c.gridheight = gridHeight;    
    c.ipady = 50;
    JPanel p1 = new JPanel();
    p1.setPreferredSize(new Dimension(panel.getWidth(), 225));
    p1.setBackground(Color.black);
    //p1.setBorder(border);
    panel.add(p1, c);

    //=========================================================== 

    // Condenser
    //===========================================================
    // Positioning
    gridXPos = 0;
    gridYPos += gridHeight;
    gridWidth = 20;
    gridHeight = 5;
    c.ipady = 0;
    // Constraints               
    //c.fill = GridBagConstraints.BOTH;
    c.weightx = 1;
    c.weighty = 0; // No space between bottom and below row?        
    c.gridx = gridXPos;
    c.gridy = gridYPos;
    c.gridwidth = gridWidth;
    c.gridheight = gridHeight;
    //c.ipady = 100;
    //c.ipady = 0;                
    // End of Constraints
    //=========================================================== 
    panel = panelCondenser();
    _Panel_MainPanel.add(panel, c);

    // Fan images - blanks
    //===========================================================
    // Positioning
    gridXPos += gridWidth;
    //gridYPos = gridHeight;  
    gridWidth = 2;
    gridHeight = 5;
    // Constraints               
    //c.fill = GridBagConstraints.BOTH;
    c.weightx = 1;
    c.weighty = 0; // No space between bottom and below row?        
    c.gridx = gridXPos;
    c.gridy = gridYPos;
    c.gridwidth = gridWidth;
    c.gridheight = gridHeight;
    //c.ipady = 100;
    //c.ipady = 0;                
    // End of Constraints
    //=========================================================== 
    label = new JLabel("");
    //label.setBorder(border);
    panel.add(label);

    _Panel_MainPanel.add(label, c);
    // Load and efficiency
    //===========================================================
    // Positioning
    gridXPos += gridWidth;
    //gridYPos = gridHeight;  
    gridWidth = 8;
    gridHeight = 10;
    // Constraints               
    //c.fill = GridBagConstraints.BOTH;
    c.weightx = 1;
    c.weighty = 0; // No space between bottom and below row?        
    c.gridx = gridXPos;
    c.gridy = gridYPos;
    c.gridwidth = gridWidth;
    c.gridheight = gridHeight;
    //c.ipady = 100;
    //c.ipady = 0;                
    // End of Constraints
    //=========================================================== 
    panel = panelLE();
    _Panel_MainPanel.add(panel, c);


    //=========================================================== 
    // Filler area
    gridYPos += gridHeight;
    gridHeight = 10;
    c.gridx = 0;
    c.gridy = gridYPos;
    c.gridwidth = 20;   
    c.gridheight = gridHeight;  
    c.ipady = 150;
    JPanel p = new JPanel();
    p.setPreferredSize(new Dimension(panel.getWidth(), 225));
    p.setBackground(Color.black);
    //p.setBorder(border);
    panel.add(p, c);

    //=========================================================== 

    // Compressor status
    //===========================================================
    // Positioning
    gridXPos = 0;
    gridYPos += gridHeight;
    gridWidth = 15;
    gridHeight = 7;
    // Constraints               
    //c.fill = GridBagConstraints.BOTH;
    c.weightx = 1;
    c.weighty = 1; // No space between bottom and below row?        
    c.gridx = gridXPos;
    c.gridy = gridYPos;
    c.gridwidth = gridWidth;
    c.gridheight = gridHeight;
    c.ipady = 0;
    //c.ipady = 0;                
    // End of Constraints
    //=========================================================== 
    panel = panelCompressor();
    _Panel_MainPanel.add(panel, c);

    //==============================================================
    // make labels white
    setLabels(_Panel_MainPanel, Colours.White.getCol());
    // do it before last panel

    // Bottom Panel
    //===========================================================
    // Constraints        
    c.fill = GridBagConstraints.BOTH;
    //c.weightx = 1;
    c.weighty = 0; // No space between bottom and below row?          
    gridXPos = 0;
    gridYPos += gridHeight;
    gridWidth = maxGridWidth;
    gridHeight = 5; // 5 per row for performance 
    c.gridx = gridXPos;
    c.gridy = gridYPos;

    c.gridwidth = gridWidth;
    c.gridheight = 1;
    //c.ipady = 100;
    //c.ipady = 0;                  
    // We dont setup next position because we are adding suction groups still

    //gridYPos += gridHeight;
    // End of Constraints
    //===========================================================
    panel = panelBottom(this.numRacks);
    _Panel_MainPanel.add(panel, c);

    _Panel_MainPanel.revalidate();
    _Panel_MainPanel.repaint();

}

問題：如何在面板上設置約束，因此它們的大小不會影響相同col / row索引中面板的大小。

Answer 1

目前，我已經成功實現了使用jpanel的網格袋布局，並添加了7個顯示面板和一些“填充”面板以獲取所需的布局。

您永遠不會被迫使用單個布局管理器。 因此，我建議您從使用BorderLayout的主面板開始。 那么您的代碼將類似於：

add(header, BorderLayout.PAGE_START);
add(gridPanel, BorderLayout.CENTER);
add(footer, BorderLayout.PAGE_END);

不能解決您的問題，但是現在您只處理網格面板中的5個面板。

如何在面板上設置約束，以使它們的大小不會影響相同col / row索引中面板的大小。

不要以為可以。 GridBagLayout的重點是使用行/列中每個組件的信息來確定單元格的大小。 我嘗試設置組件的最大大小，但是GridBagLayout似乎不尊重它。

因此，可能的解決方案是創建自己的自定義布局管理器。 應該很困難。 您可以從BorderLayout作為模板開始，因為它允許5個組件在特定位置定位。 就您而言，您似乎在不同的位置也有5個組件。