Question

问题是进度微调器只在api调用完成后加载。我想只有在我返回视图之后它才能生成。我不知道如何在进行api调用之前将其添加到Dialog中？

protected View onCreateDialogView() {

    subscriptions = null;
    LayoutInflater inflater = ((SettingsActivity) ctx).getLayoutInflater();
    final View vw = inflater.inflate(R.layout.channel_content_view, null);

    header = ((SettingsActivity) ctx).getLayoutInflater().inflate(R.layout.channels_header,null);
    ((TextView) header.findViewById(R.id.channels_header)).setText("Channels"); 

    LinearLayout linlaHeaderProgress = (LinearLayout) vw.findViewById(R.id.channelsProgress);
    linlaHeaderProgress.setVisibility(View.VISIBLE);

//        Do this in a new Thread

    final ListView lv = (ListView) vw.findViewById(R.id.list);

//        ((TextView) lv.findViewById(R.id.channel_desciption)).setText("CHANNELS");
    Thread thread = new Thread()
    {
        @Override
        public void run() {
//                      get the all the channels from api on web
                    channels = Json.getJson(apiurl + "/rest/channel/"+ linkid +"/"+ username, "GET", null);
        }
    };

    thread.start(); 

    lv.addHeaderView(header);

    return vw;
}

channel_content_view.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/channels_list"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:clickable="true"
    android:orientation="horizontal" >
    <LinearLayout
        android:id="@+id/channelsProgress"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:gravity="center"
        android:orientation="vertical"
        android:visibility="gone" >

        <ProgressBar
            android:id="@+id/pbChannelsProgress"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" >
        </ProgressBar>
    </LinearLayout>
    <ListView
        android:id="@+id/list"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:descendantFocusability="blocksDescendants" >
    </ListView>

</LinearLayout>

Answer 1

不知道这是否会起作用，但您可以尝试先创建对话框然后更改内容！

这很丑陋，可以很容易地用AsyncTask重写，但我认为它会做到这一点：

protected View onCreateDialogView() {

    subscriptions = null;
    LayoutInflater inflater = ((SettingsActivity) ctx).getLayoutInflater();
    final View vw = inflater.inflate(R.layout.channel_content_view, null);    
    LinearLayout linlaHeaderProgress = (LinearLayout) vw.findViewById(R.id.channelsProgress);
    linlaHeaderProgress.setVisibility(View.VISIBLE);
    ((TextView) header.findViewById(R.id.channels_header)).setText("Channels"); 

    //        Do this in a new Thread   
    Thread thread = new Thread()
    {
        @Override
        public void run() {
//                      get the all the channels from api on web
                    channels = Json.getJson(apiurl + "/rest/channel/"+ linkid +"/"+ username, "GET", null);
                    setListLayout(vw,linlaHeaderProgress);
        }
    };
    thread.start(); 



    return vw;
}


protected void setListLayout(View vw,View progressBar){


     runOnUiThread(new Runnable() {
                public void run() {
                    Thread.sleep(500); // to avoid super fast results from the server and always display the loader bar for a while
                    header = ((SettingsActivity) ctx).getLayoutInflater().inflate(R.layout.channels_header,null);    
                    final ListView lv = (ListView) vw.findViewById(R.id.list);
                    lv.addHeaderView(header);
                    progressBar.setVisibility(hidden);
                    lv.setVisibility(visible);

                }
            });

}

Answer 2

我有两条建议：

可能是线程执行太快，以至于在显示进度条之前提前完成。我会将线程置于睡眠模式以查看是否是这种情况。 （这只是为了确认不使用此方法会导致什么，并且会造成额外的延迟）

例如尝试放置：

  Thread thread = new Thread()
      {
          @Override
          public void run() {
          try{
             Thread.sleep(3000);
          }
          catch(Exception e){}
  //                      get the all the channels from api on web
                      channels = Json.getJson(apiurl + "/rest/channel/"+ linkid +"/"+ username, "GET", null);
          }
      };

如果上述方法不起作用，请尝试以下方法对Shwoing进度条进行检查，看看它是否有效：

调用showProgressBar（）方法，从中创建对话框的实例，如果不可能，则启动onCreateDialog方法：

  void showProgressBar(Context ctx){

    progressBar = new ProgressDialog(ctx);  //this is a context object probably ctx object will go here as 
    progressBar.setCancelable(false);
    progressBar.setMessage("Heavy Process....");
    progressBar.setProgressStyle(ProgressDialog.STYLE_SPINNER);

    progressBar.show();
    }

 protected View onCreateDialogView() {

    ///I think ctx is an Activity
    showProgressBar(ctx);  ///if it is not possible to call showProgressBar() from where you are instantiating the Dialog

     subscriptions = null;
     LayoutInflater inflater = ((SettingsActivity) ctx).getLayoutInflater();
     final View vw = inflater.inflate(R.layout.channel_content_view, null);

     header = ((SettingsActivity) ctx).getLayoutInflater().inflate(R.layout.channels_header,null);
     ((TextView) header.findViewById(R.id.channels_header)).setText("Channels"); 

    /*
     Commented below lines of Progress Bar because we are displayin it above.
     */
     //LinearLayout linlaHeaderProgress = (LinearLayout) vw.findViewById(R.id.channelsProgress);
     ///linlaHeaderProgress.setVisibility(View.VISIBLE);

 //                 Do this in a new Thread

     final ListView lv = (ListView) vw.findViewById(R.id.list);

 //        ((TextView) lv.findViewById(R.id.channel_desciption)).setText("CHANNELS");

     Thread thread = new Thread()
     {

    @Override
    public void run() {

 //                      get the all the channels from api on web

            channels = Json.getJson(apiurl + "/rest/channel/"+ linkid +"/"+ username, "GET", null);

    }

     };



     thread.start(); 

     lv.addHeaderView(header);

     return vw;
 }

此外，如果要在对话框中嵌入ProgressBar，则必须创建一个Acivity并使其显示为对话框。为此，只需添加

从Android文档页面（http://developer.android.com/guide/topics/ui/dialogs.html）下面复制：

提示：如果需要自定义对话框，则可以将“活动”显示为对话框，而不是使用“对话框API”。只需创建一个活动并将其主题设置为清单元素中的Theme.Holo.Dialog：

注意onCreateDialogView中的大多数代码都可以轻松移植到Activity onCreate（）方法

Answer 3

这对我的布局实际上是一个非常简单的问题

将我的布局改为：作品

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/channels_list"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:clickable="true"
    android:orientation="horizontal" >
    <LinearLayout
        android:id="@+id/channelsProgress"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:gravity="center"
        android:orientation="vertical"
        android:visibility="gone" >

        <ProgressBar
            android:id="@+id/pbChannelsProgress"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:descendantFocusability="beforeDescendants" >
        </ProgressBar>
    </LinearLayout>
    <ListView
        android:id="@+id/list"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:descendantFocusability="afterDescendants" >
    </ListView>

</LinearLayout>

在自定义DialogPreference中加载listview之前加载进度条

3 个答案: