Java Android Program to Demonstrate AsynChronous Tasks in Android

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Here is source code of the Program to Demonstrate AsynChronous Tasks in Android. The program is successfully compiled and run on a Windows system using Eclipse Ide. The program output is also shown below.

MainActivity.java

package com.example.asynchrounous_tasks;
 
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
 
public class MainActivity extends Activity {
    String input = "redrum ... redrum";
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button start = (Button) findViewById(R.id.button1);
        start.setOnClickListener(new View.OnClickListener() {
 
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
 
                MyAsyncTask task = new MyAsyncTask();
                task.execute(input);
            }
        });
    }
 
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
 
}

MyAsyntask.java

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package com.example.asynchrounous_tasks;
 
import android.annotation.SuppressLint;
import android.os.AsyncTask;
import android.widget.Toast;
 
@SuppressLint("ShowToast")
class MyAsyncTask extends AsyncTask<String, Integer, String> {
    @Override
    protected String doInBackground(String... parameter) {
        // Moved to a background thread.
        String result = "";
        int myProgress = 0;
        int inputLength = parameter[0].length();
        // Perform background processing task, update myProgress]
        for (int i = 1; i <= inputLength; i++) {
            myProgress = i;
            result = result + parameter[0].charAt(inputLength - i);
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
            }
            publishProgress(myProgress);
        }
        // Return the value to be passed to onPostExecute
        return result;
    }
 
    @Override
    protected void onProgressUpdate(Integer... progress) {
        // Synchronized to UI thread.
        // Update progress bar, Notification, or other UI elements
        // asyncProgress.setProgress(progress[0]);
        Toast.makeText(null, "in progress update" + progress[0],
                Toast.LENGTH_LONG).show();
    }
 
    @Override
    protected void onPostExecute(String result) {
        // Synchronized to UI thread.
        // Report results via UI update, Dialog, or notifications
    //    asyncTextView.setText(result);
        Toast.makeText(null, result, Toast.LENGTH_LONG).show();
    }
}

Activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >
 
    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="118dp"
        android:text="Demonstrating Asynchronous Tasks"
        android:textAppearance="?android:attr/textAppearanceLarge" />
 
    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:layout_below="@+id/textView1"
        android:layout_marginTop="74dp"
        android:text="Start Task" />
 
</RelativeLayout>

AndroidManifest.xml

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<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.asynchrounous_tasks"
    android:versionCode="1"
    android:versionName="1.0" >
 
    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />
 
    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.asynchrounous_tasks.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
 
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
 
</manifest>

Screenshot_2013-10-05-16-19-51

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If you wish to look at all Tutorials, go to Java Android Tutorials.

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