如何处理一个小部件并创建另一个小部件来代替 SWT 中的小部件?

How to dispose a widget and create another widget in place of that in SWT?

我有一个组合,我在启动视图时创建了五个文本框。单击一个按钮,我想用组合框替换第 4 个文本框。问题是我无法从头重新加载页面,因为我想显示文本框的当前值。

这是一个片段。

public class DisposeDemo {
  private static void addControls(Shell shell) {
    shell.setLayout(new GridLayout());
    Text textOne=new Text(shell, SWT.BORDER);
    Text textTwo=new Text(shell, SWT.BORDER);
    Text textThree=new Text(shell, SWT.BORDER);
    Text textFour=new Text(shell, SWT.BORDER);
    Text textFive=new Text(shell, SWT.BORDER);

    Button button = new Button(shell, SWT.PUSH);
    button.setText("Replace text with Combo");

    button.addSelectionListener(new SelectionAdapter() {
      @Override public void widgetSelected(SelectionEvent event) {

         //What code should go here to Replace the textFour with a combo

      }
    });
    shell.pack();
  }

  public static void main(String[] args) {
    Display display = new Display();
    Shell shell = new Shell(display);
    addControls(shell);
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch()) {
        display.sleep();
      }
    }
    display.dispose();
  }
}

与其尝试替换控件(这很棘手),不如在开始时创建所有控件,但使其中一个控件不可见并将其从布局中排除。然后您可以稍后切换可见性。

创建时使用:

Text textFour = new Text(shell, SWT.BORDER);
GridData data = new GridData(SWT.LEFT, SWT.CENTER, false, false);
textFour.setLayoutData(textFour);

Combo comboFour = new Combo(shell, ... style ...);
comboFour.setVisible(false);   // Not visible
data = new GridData(SWT.LEFT, SWT.CENTER, false, false);
data.exclude = true;   // Exclude from layout
comboFour.setLayoutData(data);

要切换为显示组合:

textFour.setVisible(false);
GridData data = (GridData)textFour.getLayoutData();
data.exclude = true;

comboFour.setVisible(true);
data = (GridData)comboFour.getLayoutData();
data.exclude = false;

shell.layout(true);   // Tell shell to redo the layout