SWT創建一個被解僱的小部件（滾動通過複合）

Question

我希望我可以創建一個我之前處理過的複合物。目標是顯示和隱藏循環複合以改變屏幕（滾動通過複合）。提前致謝。

public class prog { 
    static public void main(String[] args) { 
     final Display display = new Display(); 
     final Shell shell  = new Shell (display, SWT.CLOSE | SWT.TITLE | SWT.MIN); 
     shell.setText("EXAMPLE"); 
     shell.setLayout(new GridLayout(1,false)); 

     //I want comp1 initially be shown and then being hidden and that is shown comp2 with its components 

     final Composite comp1 = new Composite(shell, SWT.NONE); 
     comp1.setLayout(new GridLayout(1,false)); 
     comp1.setLayoutData(new GridData(GridData.FILL, GridData.FILL, true, true)); 

     final Composite comp2 = new Composite(shell, SWT.BORDER); 
     comp2.setLayoutData(new GridData(GridData.FILL, GridData.FILL, true, true)); 

     GridData data = (GridData)comp2.getLayoutData(); // Assumes layout was set earlier 
     data.exclude = true; // Don't include control in the layout 

     comp2.setVisible(false); 

     comp2.layout(true); 

     Label t = new Label(comp2, SWT.NONE); 
     t.setText("must be shown"); 

     Button btn_create = new Button(comp1, SWT.PUSH); 
     btn_create.setText("change composite"); 
     btn_create.setLayoutData(new GridData(GridData.FILL, GridData.FILL, true, true,1,1)); 

     btn_create.addSelectionListener(new SelectionAdapter() {  //evento quando il bottone viene premuto 
      public void widgetSelected(SelectionEvent e) { 
       GridData data3 = (GridData)comp1.getLayoutData(); // Assumes layout was set earlier 

       data3.exclude =  true; // Don't include control in the layout 

       comp1.setVisible(false); 

       comp1.layout(true); 

       GridData data2 = (GridData)comp2.getLayoutData(); // Assumes layout was set earlier 

       data2.exclude = false; // Don't include control in the layout 

       comp2.setVisible(true); 

       comp2.layout(true); 
       System.out.println(comp2.getVisible()); 



      }}); 

     //swt_create.create(display, shell, create);  
     shell.setSize(500, 100); 

     shell.addControlListener(new ControlAdapter() {  // fa in modo che la dimensione della finestra si sempre 
      public void controlResized(ControlEvent e) { // uguale 
       shell.setSize(500,400); 
      } 
     }); 
     shell.open(); 
     shell.pack();   

     while (!shell.isDisposed()) { 
       if (!display.readAndDispatch()) { // questo etodo serve a leggere gli eventi che compiamo durante 
         display.sleep();   // l'esecuzione, quando si clicca sulla x si passa avanti e il ciclo viene 
       }         // chiuso 
      } 

     display.dispose(); 
}} 

Answer 1

一旦一個控件已經被處置，它就消失了，不能被重用。

您可以通過在控件上調用setVisible(false)來暫時隱藏控件，使其不可見。

當您使控件可見/不可見時，您需要更新父Composite的佈局。根據您用於Composite的佈局，您可能還需要調整佈局。

例如，如果你正在使用GridLayout父複合您可以使用GridData的exclude選擇離開了控制：

GridData data = (GridData)control.getLayoutData(); // Assumes layout was set earlier 

data.exclude = true; // Don't include control in the layout 

control.setVisible(false); 

.... 

parentComposite.layout(true); 

要顯示控制反向設置：

GridData data = (GridData)control.getLayoutData(); // Assumes layout was set earlier 

data.exclude = false; // Include control in the layout 

control.setVisible(true); 

.... 

parentComposite.layout(true);