SWT/Jface 怎么销毁控件，怎么重新生成控件

SWT/Jface 如何销毁控件，如何重新生成控件？

看到网上有人提出这样的问题，他的代码是有些问题的。

不在乎问题有多深，在乎解决方法和点滴的积累。

完整的小例子，大家可以跑跑，点点。

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

public class DynamSample{
    Display display;
    Shell shell;
    Composite c;
    Composite c1;
    Composite c2;
   
    public DynamSample(){
        display = new Display();
        shell = new Shell(display);
        shell.setText("SWT Sample");
        shell.setLayout( new FillLayout(SWT.VERTICAL));
       
        c = new Composite(shell, SWT.NONE);
        c.setLayout( new FillLayout() );
       
        createGui1();
        createGui2();
       
        shell.open();
        while (!shell.isDisposed())
              if (!display.readAndDispatch())
                display.sleep();
   
    }
   
    private void createGui1(){
        c1 = new Composite(c, SWT.NONE);
        c1.setLayout(new GridLayout(1, true));
        Button b1 = new Button( c1, SWT.NONE);
        b1.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
        b1.setText("Button 1");
        b1.addSelectionListener(new SelectionListener(){
            @Override
            public void widgetDefaultSelected(SelectionEvent e) {
            }
            @Override
            public void widgetSelected(SelectionEvent e) {
                c1.dispose(); //先销毁了
                createGui3(); //在重新加载上？？？但不成功

                 //按添加的
                c1.layout();
                c.layout();
                //
            }});
    }
    private void createGui2(){
        Composite c2 = new Composite(c, SWT.NONE);
        c2.setLayout(new GridLayout( 1, true ));
        Button b2 = new Button( c2, SWT.NONE);
        b2.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
        b2.setText("Button 2");
        b2.addSelectionListener(new SelectionListener(){
            @Override
            public void widgetDefaultSelected(SelectionEvent e) {
            }
            @Override
            public void widgetSelected(SelectionEvent e) {
                        // 功能如上
            }
        });
    }
    private void createGui3(){
        c1 = new Composite(c, SWT.NONE);
        c1.setLayout(new GridLayout( 1, true ));
        Button b1 = new Button( c1, SWT.NONE);
        b1.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
        b1.setText("Button 2222222");
        b1.addSelectionListener(new SelectionListener(){
            @Override
            public void widgetDefaultSelected(SelectionEvent e) {
            }
            @Override
            public void widgetSelected(SelectionEvent e) {
                        // 功能如上
            }
        });
    }
    public static void main(String args[]){
            new DynamSample();
    }
   

}