Question

我正在使用此代码

测试GWT StackLayoutPanel类

public class MenuView extends StackLayoutPanel {

    interface Binder extends UiBinder<StackLayoutPanel, MenuView> {
    }

    private static final Binder binder = GWT.create(Binder.class);

    @UiField Users users;

    @UiField Configurations configurations;

    public MenuView(Unit unit) {
        super(unit);
        initWidget(binder.createAndBindUi(this));
    }

    @Override
    public int getVisibleIndex() {
        return super.getVisibleIndex();
    }

    @Override
    public Widget getVisibleWidget() {
        return super.getVisibleWidget();
    }
}


————————————————————————

public class Users extends Composite {

    /**
     * Callback when user items are selected.
     */
    public interface Listener {
        void onUserSelected(User user);
    }

    /**
     * Sets the listener that will be notified when an item is selected.
     */
    public void setListener(Listener listener) {
        this.listener = listener;
    }

    @SuppressWarnings("unused")
    private Listener listener;

    interface Binder extends UiBinder<Widget, Users> {
    }

    interface Style extends CssResource {
        String item();
    }

    private static final Binder binder = GWT.create(Binder.class);

    @UiField
    ComplexPanel panel;
    @UiField
    Style style;

    public Users() {
        initWidget(binder.createAndBindUi(this));
    }
}

MenuView.ui.xml File
<ui:UiBinder
  <g:StackLayoutPanel styleName='{style.menuview}' unit='EM'>
    <g:stack>
      <g:header size='3'><div class='{style.stackHeader}'><div class='{style.usersIcon}'/> Users</div></g:header>
      <sensport:Users ui:field='users'/>
    </g:stack>
  </g:StackLayoutPanel>
</ui:UiBinder>

user.ui.xml File
<ui:UiBinder>
  <g:FlowPanel styleName='{style.users}' ui:field='panel'/>
</ui:UiBinder>

当我运行测试时，我获得了一个java IllegalStateException。您是否知道此错误？

java.lang.IllegalStateException：Composite.initWidget（）只能被调用一次。在com.google.gwt.user.client.ui.Composite.initWidget（Composite.java:127）在com.google.gwt.user.client.ui.ResizeComposite.initWidget（ResizeComposite.java:30）在be.lilab.sensport.client.MenuView。＆lt; init＆gt;（MenuView.java:26） at be.lilab.sensport.client.Sensport_BinderImpl $ Widgets.build_menuView（Sensport_BinderImpl.java:122） at be.lilab.sensport.client.Sensport_BinderImpl $ Widgets.get_menuView（Sensport_BinderImpl.java:118） at be.lilab.sensport.client.Sensport_BinderImpl $ Widgets.build_f_SplitLayoutPanel2（Sensport_BinderImpl.java:106） at be.lilab.sensport.client.Sensport_BinderImpl $ Widgets.get_f_SplitLayoutPanel2（Sensport_BinderImpl.java:100） at be.lilab.sensport.client.Sensport_BinderImpl $ Widgets.build_f_DockLayoutPanel1（Sensport_BinderImpl.java:73） at be.lilab.sensport.client.Sensport_BinderImpl $ Widgets.get_f_DockLayoutPanel1（Sensport_BinderImpl.java:66） at be.lilab.sensport.client.Sensport_BinderImpl $ Widgets.access $ 0（Sensport_BinderImpl.java:65）在be.lilab.sensport.client.Sensport_BinderImpl.createAndBindUi（Sensport_BinderImpl.java:15）在be.lilab.sensport.client.Sensport_BinderImpl.createAndBindUi（Sensport_BinderImpl.java:1）在be.lilab.sensport.client.Sensport.onModuleLoad（Sensport.java:47） at sun.reflect.NativeMethodAccessorImpl.invoke0（Native Method） at sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:57） at sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43） at java.lang.reflect.Method.invoke（Method.java:606）在com.google.gwt.dev.shell.ModuleSpace.onLoad（ModuleSpace.java:411）在com.google.gwt.dev.shell.OophmSessionHandler.loadModule(OophmSessionHandler.java:200）在com.google.gwt.dev.shell.BrowserChannelServer.processConnection（BrowserChannelServer.java:526）在com.google.gwt.dev.shell.BrowserChannelServer.run（BrowserChannelServer.java:364）在java.lang.Thread.run（Thread.java:745）

Answer 1

您正在扩展StackLayoutpanel，它扩展了ResizeComposite。在StackLayoutPanel的构造函数中，调用initWidget方法。

所以，再次使用：

调用它

public MenuView(Unit unit) {
    super(unit);
    initWidget(binder.createAndBindUi(this));
}

会导致异常。在您的情况下，可能的解决方案是扩展Composite。

    public class MenuView extends Composite {

    interface Binder extends UiBinder<StackLayoutPanel, MenuView> {
    }

    private static final Binder binder = GWT.create(Binder.class);

    @UiField Users users;

    @UiField Configurations configurations;

    @UiField StackLayoutPanel panel;

    public MenuView(Unit unit) {
        super(unit);
        initWidget(binder.createAndBindUi(this));
    }

    @Override
    public int getVisibleIndex() {
        return panel.getVisibleIndex();
    }

    @Override
    public Widget getVisibleWidget() {
        return panel.getVisibleWidget();
    }
}

更新您的MenuViewui.xml：

<ui:UiBinder
  <g:StackLayoutPanel ui:field='panel' styleName='{style.menuview}' unit='EM'>
    <g:stack>
      <g:header size='3'><div class='{style.stackHeader}'><div class='{style.usersIcon}'/> Users</div></g:header>
      <sensport:Users ui:field='users'/>
    </g:stack>
  </g:StackLayoutPanel>
</ui:UiBinder>

使用StackLayoutPanel和StackPanel时出现java IllegalStateException

1 个答案: