Learn About StartActivity For Result in Android

Amir Ali
10y
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Introduction

This article explains StartActvityForResult in Android.

StartActivityForResult

StartActivityForResult is a method for starting an activity for which you would like a result when it is finished. It is provided by the Activity class.

Step 1

Create an XML file with the following:. This is the activity_main file that consists of one text view and a button in a relative layout.

<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"
android:background="#cf99ff"
tools:context=".MainActivity" >

<TextView
android:id="@+id/txtView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerInParent="true"
android:textSize="30dp"
android:text="Message"
android:textStyle="bold"/>

<Button
android:id="@+id/btn_get"
android:layout_width="150dp"
android:layout_height="80dp"
android:layout_below="@+id/txtView1"
android:layout_marginLeft="65dp"
android:layout_marginTop="42dp"
android:text="GetMessage" />
</RelativeLayout>

Step 2

Create another XML file with the following:. This is my second XML file that consists of an edittext, a textview and a button.

<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"
android:background="#cf99ff"
tools:context=".SecondActivity" >

<EditText
android:id="@+id/editText1"
android:textStyle="bold"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="40dp"
android:layout_alignParentTop="true"
android:ems="10" />

</RelativeLayout>

Step 3

Create a Java class file with the following:

package com.startactivityforresult;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

//This class extends the Activity class that provides some methods for the activity. In this i have set the button onItsClickListener, so on click another activity will be start and startActivityForResult() will the intent with request code.

public class MainActivity extends Activity {
TextView txtview1;
Button btn_get;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
txtview1=(TextView)findViewById(R.id.txtView1);
btn_get=(Button)findViewById(R.id.btn_get);
//button set on its click listener
btn_get.setOnClickListener(new OnClickListener() {
// when you click on the button onClick() will be invoke and startActivityForResult() will be invoke
@Override
public void onClick(View arg0) {
//create the object of intent
Intent i=new Intent(MainActivity.this,Second.class);startActivityForResult(i, 2);// Activity is started with requestCode 2
}
});
}

// This method is called when from the second Activity setResult() will be called by ing requestcode and an intent.

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
super.onActivityResult(requestCode, resultCode, data);
// check if the request code is same as what is ed here it is 2
if(requestCode==2)
{
String message=data.getStringExtra("MESSAGE");
txtview1.setText(message);
}
}

@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;
}
}

Step 4

public class Second extends Activity {
EditText edtText1;
Button btn;
@Override
protected void onCreate(Bundle savedInstanceState) {\
super.onCreate(savedInstanceState);
setContentView(R.layout.second);
edtText1=(EditText)findViewById(R.id.editText1);
btn=(Button)findViewById(R.id.btn);
btn.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
String message=edtText1.getText().toString();
Intent i=new Intent();
i.putExtra("MESSAGE",message);
setResult(2,i);
finish();//finishing activity
}
});
}

@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;
}
}

Step 5

The following is the Android Manifest.XML file. In the Android Manifest.xml file you will declared the second activity.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.startactivityforresult"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="18" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.startactivityforresult.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>
<activity
android:name=".Second"></activity>
</application>
</manifest>