CODEWITHSUNDEEP
androidandroid-asynctask
Subburaj
Subburaj

Reputation: 5192

Process dialog in Android

As i am new to this "Async task" concept in android,i searched a lot of posts and i implemented.In my application when opening the application i am fetching lot of images from url,so its delaying a lot to open.So i have an idea to have an activity when opening the application.I have tried for the following:

My activity code:

       Gallery glly;
     public void onCreate(Bundle savedInstanceState) 
        { 

            this.requestWindowFeature(Window.FEATURE_NO_TITLE);
            super.onCreate(savedInstanceState);
            setContentView(R.layout.galleryview);   

            new RestoreDBTask().execute();
        }
      class RestoreDBTask extends AsyncTask <Void, Void, Nodelist>
        {
            private ProgressDialog dialog;
            Context ctx;

            public RestoreDBTask( Context ctx) {

                this.ctx = ctx;

            }

            @Override
            protected void onPreExecute()
            {
                dialog = ProgressDialog.show(
                    ctx,"Please Wait","Loading...", true);
            }

            @Override
            protected Nodelist doInBackground(Void... params)
            {
                 final String URLHeading = "http://m.indiatoday.in/xml/stories/sections_listing.xml";

                 Heading parser = new Heading();       
                 String xmldata = parser.getXmlFromUrl(URLHeading);       
                 Document domelement = parser.getDomElement(xmldata);       
                 NodeList node = domelement.getElementsByTagName("item");  



                     context.getInstance().setAppVariable("flag", "Home");
                 adapter=new GalleryviewAdapter(NewspapperActivity.this);
//                  GalleryviewAdapter adapter= new GalleryviewAdapter();
                 adapter.getelement("http://m.bvdjujd.in/xml/stories/jusdjhs.xml",1);   


    return node;

    }
     @Override
            protected void onPostExecute(String result)
            {
Element e0 = (Element) node.item(0);
                    txt1.setText(parser.getValue(e0, "sectionname"));

                    Element e1 = (Element) node.item(1);
                    txt2.setText(parser.getValue(e1, "sectionname"));

                    Element e2 = (Element) node.item(2);
                    txt3.setText(parser.getValue(e2, "sectionname"));

                    Element e3 = (Element) node.item(3);
                    txt4.setText(parser.getValue(e3, "sectionname"));

                    Element e4 = (Element) node.item(4);

                    txt5.setText(parser.getValue(e4, "sectionname"));

  glly.setAdapter(adapter);
           DisplayMetrics metrics1 = new DisplayMetrics(); 
           getWindowManager().getDefaultDisplay().getMetrics(metrics1); 
           MarginLayoutParams mlp1 = (MarginLayoutParams) glly.getLayoutParams(); 
           mlp1.setMargins(-(metrics1.widthPixels/2+40),mlp1.topMargin,mlp1.rightMargin, mlp1.bottomMargin );


                dialog.dismiss();
            }


    }

My logcat:

03-12 10:24:08.430: I/Process(487): Sending signal. PID: 487 SIG: 9
03-12 10:24:22.140: D/dalvikvm(511): GC freed 2643 objects / 197184 bytes in 168ms
03-12 10:24:24.800: I/MemoryCache(511): MemoryCache will use up to 6.0MB
03-12 10:24:24.810: W/dalvikvm(511): threadid=15: thread exiting with uncaught exception (group=0x4001b188)
03-12 10:24:24.845: E/AndroidRuntime(511): Uncaught handler: thread AsyncTask #1 exiting due to uncaught exception
03-12 10:24:24.932: E/AndroidRuntime(511): java.lang.RuntimeException: An error occured while executing doInBackground()
03-12 10:24:24.932: E/AndroidRuntime(511):  at android.os.AsyncTask$3.done(AsyncTask.java:200)
03-12 10:24:24.932: E/AndroidRuntime(511):  at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
03-12 10:24:24.932: E/AndroidRuntime(511):  at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
03-12 10:24:24.932: E/AndroidRuntime(511):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
03-12 10:24:24.932: E/AndroidRuntime(511):  at java.util.concurrent.FutureTask.run(FutureTask.java:137)
03-12 10:24:24.932: E/AndroidRuntime(511):  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1068)
03-12 10:24:24.932: E/AndroidRuntime(511):  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:561)
03-12 10:24:24.932: E/AndroidRuntime(511):  at java.lang.Thread.run(Thread.java:1096)
03-12 10:24:24.932: E/AndroidRuntime(511): Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
03-12 10:24:24.932: E/AndroidRuntime(511):  at android.os.Handler.<init>(Handler.java:121)
03-12 10:24:24.932: E/AndroidRuntime(511):  at com.newspapper.ImageLoader.<init>(ImageLoader.java:29)
03-12 10:24:24.932: E/AndroidRuntime(511):  at com.newspapper.GalleryviewAdapter.<init>(GalleryviewAdapter.java:52)
03-12 10:24:24.932: E/AndroidRuntime(511):  at com.newspapper.NewspapperActivity$RestoreDBTask.doInBackground(NewspapperActivity.java:569)
03-12 10:24:24.932: E/AndroidRuntime(511):  at com.newspapper.NewspapperActivity$RestoreDBTask.doInBackground(NewspapperActivity.java:1)
03-12 10:24:24.932: E/AndroidRuntime(511):  at android.os.AsyncTask$2.call(AsyncTask.java:185)
03-12 10:24:24.932: E/AndroidRuntime(511):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
03-12 10:24:24.932: E/AndroidRuntime(511):  ... 4 more
03-12 10:24:25.000: I/dalvikvm(511): threadid=7: reacting to signal 3
03-12 10:24:25.214: I/dalvikvm(511): Wrote stack trace to '/data/anr/traces.txt'

Please help me to solve this.ALso help me that whether i am doing the right way..Thanks in advance..

Upvotes: 0

Views: 589

Answers (1)

ρяσѕρєя K
ρяσѕρєя K

Reputation: 132982

you are getting

The method findViewById(int) is undefined for the type RestoreDBTask

because you are trying to access UI elements from RestoreDBTask class . you can solved this issue using Activity context instead of RestoreDBTask as :

TextView txt1 = (TextView)Your_Activity_Name.this.findViewById(R.id.Text01);
TextView txt2 = (TextView)Your_Activity_Name.this.findViewById(R.id.Text02);
TextView txt3 = (TextView)Your_Activity_Name.this.findViewById(R.id.Text03);
//....

but when u try to running current app you will get following error :

alledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.

fto avoid this error you will need following Streps :

1. First get data from webservice inside doInBackground.

2. Return NodeList node from doInBackground method

3. finally get NodeList in onPostExecute and do your xml parsing then access or update UI elements

Example :-

 class RestoreDBTask extends AsyncTask <Void, Void, NodeList>
    {
    ///.. your code here.....
        @Override
        protected NodeList doInBackground(Void... params)
        {

           //....your code here..
           return node; 
         }
 @Override
        protected void onPostExecute(NodeList result)
        {
            // get data from result
             ....
            // access UI elements here add value to it
            TextView txt1 = (TextView)Your_Activity_Name.
                                           this.findViewById(R.id.Text01);
            TextView txt2 = (TextView)Your_Activity_Name.
                                           this.findViewById(R.id.Text02);
            ......
            dialog.dismiss();
        }
 }

Upvotes: 2

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