加载屏幕在黑莓手机上不起作用？

Question

我想在黑莓上实现加载屏幕。我尝试以下代码 使用以下代码支持论坛链接

PleaseWaitPopupScreen.showScreenAndWait(new Runnable() {

        public void run() {
                           //**Segment 1** here i write the code for  network call
                                    }
                           }, "please wait");
                     // **Segment 2**:Here processing the data get from network call

问题是第 2 段在完成第 1 段之前起作用。我也尝试使用以下代码，但

HorizontalFieldManager popHF = new HorizontalFieldManager();
    popHF.add(new LabelField("Pls wait..."));
    final PopupScreen waitScreen = new PopupScreen(popHF);
    new Thread()
    {
        public void run() 
        {

            synchronized (UiApplication.getEventLock()) 
            {
                UiApplication.getUiApplication().pushScreen(waitScreen);
            }
           // **Segment 1**Here Some Network Call 

          synchronized (UiApplication.getEventLock()) 
            {
                UiApplication.getUiApplication().popScreen(waitScreen);

            }
         }
     }.start();
     // **Segment 2**:Here processing the data get from network call

出现了同样的问题。任何帮助将不胜感激。

谢谢

Answer 1

实际上，这取决于您在段 2 中执行的操作。如果没有 UI 操作，则只需将段 2 移动到进行 http 调用的线程内即可。例如：

final PopupScreen waitScreen = new PopupScreen(popHF);
new Thread()
{
    public void run() 
    {
        synchronized (UiApplication.getEventLock()) 
        {
            UiApplication.getUiApplication().pushScreen(waitScreen);
        }
        // **Segment 1**Here Some Network Call

        // **Segment 2**:Here processing the data get from network call

        synchronized (UiApplication.getEventLock()) 
        {
            UiApplication.getUiApplication().popScreen(waitScreen);
        }
     }
 }.start();

但是如果段 2 中有 UI 操作，则在弹出等待屏幕后立即在 UI 线程上调用它：

final PopupScreen waitScreen = new PopupScreen(popHF);
new Thread()
{
    public void run() 
    {
        synchronized (UiApplication.getEventLock()) 
        {
            UiApplication.getUiApplication().pushScreen(waitScreen);
        }
        // **Segment 1**Here Some Network Call

        synchronized (UiApplication.getEventLock()) 
        {
            UiApplication.getUiApplication().popScreen(waitScreen);
            // **Segment 2**:Here processing the data get from network call
        }
     }
 }.start();