小编use*_*916的帖子

在EntryPoint类中,我加载了一个自定义构建westPanel.从这个WestPanel我想替换我的EntryPoint类上存在的DockLayoutPanel的中心.

这是我的EntryPoint类:

public class MainEntryPoint implements EntryPoint {
    private VerticalPanel mainPanel = new VerticalPanel();
    private DockLayoutPanel dockLayoutPanel = new DockLayoutPanel(Unit.EM);
    private NorthMenu northMenu = new NorthMenu();
    private VerticalPanel mainPanel = new VerticalPanel();
    //other panels

    @Override
    public void onModuleLoad() {
        dockLayoutPanel.addNorth(northMenu, 40);
        dockLayoutPanel.add(mainPanel);
        //add other panels
        RootLayoutPanel panel = RootLayoutPanel.get();
        panel.add(dockLayoutPanel);     
    }
}

WestPanel应该用MyOtherPanel替换DockLayout的mainPanel:

public class WestMenu extends Composite {
    private StackLayoutPanel stackLayoutPanel = new StackLayoutPanel(Unit.EM);  
    public WestMenu(){  
        Tree configuration = new Tree();
        configuration.addSelectionHandler( new SelectionHandler(){
            @Override
            public void onSelection(SelectionEvent event) …