(Android practice) AsycTask achieves asynchronous loading

1Implementation Effect description:

1.1
DisplayLoading

 

1.2 after the question information is loaded, bind the question

 

1.3 loading failed, goLoading failed

 

 

2Asynchronous loading implementation

2.1Interface settings

Interface before loading

 

View Code

<? Xml version = "1.0" encoding = "UTF-8"?>
<LinearLayout xmlns: android = "http://schemas.android.com/apk/res/android"
Android: layout_width = "fill_parent"
Android: layout_height = "fill_parent"
Android: background = "# ffffff"
Android: orientation = "horizontal"
>
<ProgressBar
Android: id = "@ + id/circleProgressBar"
Style = "? Android: attr/progressBarStyleLarge "mce_style = "? Android: attr/progressBarStyleLarge"
Android: layout_width = "wrap_content"
Android: layout_height = "wrap_content"
Android: visibility = "gone"
Android: max = "100"
Android: progress = "20"
/>
<TextView android: text = "loading information ..... "
Android: id = "@ + id/textView1"
Android: layout_width = "wrap_content"
Android: textColor = "#000000"
Android: layout_height = "wrap_content"> </TextView>
</LinearLayout>

Loading failure page

 

<? Xml version = "1.0" encoding = "UTF-8"?>
<LinearLayout xmlns: android = "http://schemas.android.com/apk/res/android"
Android: layout_width = "fill_parent"
Android: layout_height = "fill_parent"
Android: background = "# ffffff"
Android: orientation = "horizontal"
>
<TextView android: text = "network exception, data cannot be loaded" android: id = "@ + id/textView1" android: layout_width = "wrap_content" android: layout_height = "wrap_content"> </TextView>
<Button android: text = "reload" android: id = "@ + id/button1" android: layout_width = "wrap_content" android: layout_height = "wrap_content"> </Button>

</LinearLayout>

2.2Create a custom asynchronous class

 

//AsyncTask    class AsyncLoader_GuessInfo extends AsyncTask<String, Void, Integer>{      @Override      protected Integer doInBackground(String... params) {         int result=0;      try{      gi=GuessDataServiceHelper.GetGuessInfo(params[0]);      result=2;      }         catch(Exception ex){         result=-1;          }              return result;      }     }

 

 

2.3Call asynchronous classes,Different content is displayed based on the feedback.

View Code

/*
* Downloads question information.
**/
Private BegindownHandler mbegindownHandler = new BegindownHandler ();

Class BegindownHandler extends Handler {
@ Override
Public void handleMessage (Message msg ){
AsyncTask <String, Void, Integer> results = new asyncloader_guessinfo(cmd.exe cute (GuessNo );
Try {
If (results. get () = 2)
{
LoadAndBandingData (GuessNo );
}
Else
SetContentView (R. layout. async_error );
}
Catch (Exception ex)
{
SetContentView (R. layout. async_error );

}

}
Public void sleep (long delayMillis ){
This. removeMessages (0 );
SendMessageDelayed (obtainMessage (0), delayMillis );
}
};