Lesson 7: Background Tasks

Name : SAFIRA AINI

Student ID : 1202154315

Class : SI-39-03

Lesson 7: Background Tasks

7.1: Membuat AsyncTask

Tugas 1: Menyiapkan Proyek SimpleAsyncTask

1.1 Membuat layout

Code :

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:paddingLeft="@dimen/activity_horizontal_margin"
     android:paddingRight="@dimen/activity_horizontal_margin"
     android:paddingTop="@dimen/activity_vertical_margin"
     android:paddingBottom="@dimen/activity_vertical_margin"
     android:orientation="vertical">
 
     <TextView
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="@string/ready_to_start"
         android:id = "@+id/textView1"
         android:textSize="24sp"/>
 
     <Button
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="@string/start_task"
         android:id="@+id/button"
         android:layout_marginTop="56dp"
         android:onClick="startTask" />
 </LinearLayout>

Tugas 2: Membuat subkelas AsyncTask

2.1 Menjadikan AsyncTask Subkelas

2.2 Mengimplementasikan doInBackground()

Code :

@Override
 protected String doInBackground(Void... voids) {
 
 
     Random r = new Random();
     int n = r.nextInt(11);
 
 
     int s = n * 200;
 
 
     try {
         Thread.sleep(s);
     } catch (InterruptedException e) {
         e.printStackTrace();
     }
 
     // Return a String result
     return "Awake at last after sleeping for " + s + " milliseconds!";
 }

2.3 Mengimplementasikan onPostExecute()

Tugas 3: Mengimplementasikan Langkah Terakhir

3.1 Implementasikan metode yang mulai dengan AsyncTask

3.2 Mengimplementasikan onSaveInstanceState()

Code :

 package android.example.com.simpleasynctask;
 
 import android.os.Bundle;
 import android.support.v7.app.AppCompatActivity;
 import android.view.View;
 import android.widget.TextView;
 
 
 public class MainActivity extends AppCompatActivity {
 
 
     private static final String TEXT_STATE = "currentText";
 
     private TextView mTextView;
 
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
         //  Initialize mTextView
         mTextView = (TextView) findViewById(R.id.textView1);
 
         // Restore TextView if there is a savedInstanceState
         if(savedInstanceState!=null){
            mTextView.setText(savedInstanceState.getString(TEXT_STATE));
         }
     }
 
  public void startTask (View view) {
         // Put a message in the text view
         mTextView.setText(R.string.napping);
 
         // Start the AsyncTask.
         // The AsyncTask has a callback that will update the text view.
         new SimpleAsyncTask(mTextView).execute();
     }
 
     @Override
     protected void onSaveInstanceState(Bundle outState) {
         super.onSaveInstanceState(outState);
         // Save the state of the TextView
         outState.putString(TEXT_STATE, mTextView.getText().toString());
     }
 }