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1/13www.vogella.com/articles/AndroidIntent/article.html
by Lars Vogel
Tutorial
306
Android Intents - Tutorial
Lars Vogel
Version 2.7
Copyright © 2009, 2010, 2011, 2012 Lars Vogel
17.07.2012
Revision History
Revision 0.1 20.07.2010 Lars
Vogel
Created
Revision 0.2 - 2.7 19.07.2010 - 17.07.2012 Lars
Vogel
bug fixes and enhancements
Using Intents in Android
This tutorials describes what Intents are and how to use them in Android. It is based on Eclipse 3.7, Java 1.6
and Android 4.0.4 (Ice Cream Sandwich).
Table of Contents
1. Android Intents
1.1. Overview1.2. Explicit Intents1.3. Implicit Intents1.4. Data Transfer
2. Using Intents to call Activities
2.1. Calling Activities2.2. Calling Sub-Activities for result data
3. Defining Intent Filters
3.1. Overview3.2. Restrictions as of Android 3.1
4. Intents as event triggers5. Share Intent and ShareActionProvider6. Finding out if an Intent is available7. Prerequisites for this tutorial8. Tutorial: Explicit intents and data transfer betweenactivities9. Tutorial: Implicit Intents10. Tutorial: Registering an IntentFilter11. Tutorial: Picking an Image via Intent12. Thank you13. Questions and Discussion14. Links and Literature
14.1. Source Code14.2. Android Resources14.3. vogella Resources
1. Android Intents
1.1. Overview
Intents are asynchronous messages which allow Android components to request functionality from other
components of the Android system. For example an Activity can send an Intents to the Android
system which starts another Activity.
Therefore Intents allow to combine loosely coupled components to perform certain tasks.
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Intents can be used to signal to the Android system that a certain event has occurred. Other components
in Android can register to this event and will get notified.
Intents are instances of the android.content.Intent class.
Intents are send to the Android system. Depending on how the Intent was constructed the Android
system will run an receiver determination and determine what to do.
An Intent can also contain data. This data can be used by the receiving component. For example your
application can calls via an Intent a browser component. As data it may send the URL to the browser
component.
Android supports explicit and implicit Intents.
1.2. Explicit Intents
Explicit Intents explicitly names the component which should be called by the Android system, by using the
Java class as identifier.
The following shows an explicit Intent. If that Intent is correctly send to the Android system, it will start
the associated class.
Intent i = new Intent(this, ActivityTwo.class);i.putExtra("Value1", "This value one for ActivityTwo ");i.putExtra("Value2", "This value two ActivityTwo");
Explicit Intents are typically used within on application as the classes in an application are controlled by
the application developer.
1.3. Implicit Intents
Implicit Intents do not directly specify the Android components which should be called. They specify the
action which should be performed and optionally an URI which should be used for this action.
For example the following tells the Android system to view a webpage. Typically the web browser is
registered to this Intent but other component could also register themself to this event.
Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("http://www.vogella.com"));
If these Intents are send to the Android system it searches for all components which are registered for the
specific action and the data type.
If only one component is found, Android starts this component directly. If several components are identifier by
the Android system, the user will get an selection dialog and can decide which component should be used for
the Intent.
1.4. Data Transfer
An implicit Intent contains the Action and optional the URI. The receiving component can get this
information via the getAction() and getData() methods.
Explicit and implicit Intents can also contain additional data. This data call be filled by the component
which creates the Intent. It can and can get extracted by the component which receives the Intent.
The component which creates the Intent can add data to it via the overloaded putExtra() method.
Extras are key/value pairs; the key is always a String. As value you can use the primitive data types (int,
float,..), String, Bundle, Parceable and Serializable.
For example you can trigger all components which have been registered to send some data via the new
Intent(Intent.ACTION_SEND) This Intent determines possible receivers via the type. What is send
it defined via the putExtra method. You can use any String as key, the following uses the keys which are
predefined for the ACTION_SEND intent.
Intent intent = new Intent(Intent.ACTION_SEND);intent.setType("text/plain");intent.putExtra(android.content.Intent.EXTRA_TEXT, "News for you!");startActivity(intent);
The component which receives the Intent can use the getIntent().getExtras() method call to get
the extra data.
Bundle extras = getIntent().getExtras();if (extras == null) { return;
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}// Get data via the keyString value1 = extras.getString(Intent.EXTRA_TEXT);if (value1 != null) { // Do something with the data}
2. Using Intents to call Activities
2.1. Calling Activities
If you send an Intent to the Android system, Android requires that you tell it to which type of component
your Intent should be send.
To start an Activity use the method startActivity(Intent). This method is defined on the
Context object and available in every Activity object.
If you call an Activity with the startActivity(Intent) method the caller requires no result from the
called Activity.
2.2. Calling Sub-Activities for result data
If you need some information from the called Activity use the startActivityForResult() method.
public void onClick(View view) { Intent i = new Intent(this, ActivityTwo.class); i.putExtra("Value1", "This value one for ActivityTwo "); i.putExtra("Value2", "This value two ActivityTwo"); // Set the request code to any code you like, you can identify the // callback via this code startActivityForResult(i, REQUEST_CODE);}
If you use the startActivityForResult() method then the started Activity is called a Sub-
Activity.
If the Sub-Activity is finished it can send data back to its caller via Intent. This is done in the finish()
method.
@Overridepublic void finish() { // Prepare data intent Intent data = new Intent(); data.putExtra("returnKey1", "Swinging on a star. "); data.putExtra("returnKey2", "You could be better then you are. "); // Activity finished ok, return the data setResult(RESULT_OK, data); super.finish();}
Once the Sub-Activity finished, the onActivityResult() method in the calling Activity will be
called.
@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) { if (resultCode == RESULT_OK && requestCode == REQUEST_CODE) { if (data.hasExtra("returnKey1")) { Toast.makeText(this, data.getExtras().getString("returnKey1"), Toast.LENGTH_SHORT).show(); } }}
3. Defining Intent Filters
3.1. Overview
If an Intent is send to the Android system, it will determine suitable applications for this Intent. If several
components have been registered for this type of Intent, Android offers the user the choice to open one of
them.
This determination is based on IntentFiltes. An IntentFilter specifies the types of Intent that
an activity, service, or broadcast receiver can respond to. An IntentFilter declares the capabilities of a
component. It specifies what an Activity or Service can do and what types of broadcasts a Receiver can
handle. It allows the corresponding component to receive Intents of the declared type.
IntentFilters are typically defined via the AndroidManifest.xml file. For BroadcastReceiver it is
also possible to define them in coding. An IntentFilters is defined by its category, action and data
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filters. It can also contain additional metadata.
The following will register an Activity for the Intent which is triggered when someone wants to open a
webpage.
<activity android:name=".BrowserActivitiy" android:label="@string/app_name"> <intent-filter> <action android:name="android.intent.action.VIEW" /> <category android:name="android.intent.category.DEFAULT" /> <data android:scheme="http"/> </intent-filter></activity>
The following example will register an Activity for the ACTION_SEND intent for the text/plain mime type.
<activity android:name=".ActivityTest" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.SEND" /> <category android:name="android.intent.category.DEFAULT" />
<data android:mimeType="text/plain" /> </intent-filter>
</activity>
If a component does not define Intent filters, it can only be called by explicit Intents.
3.2. Restrictions as of Android 3.1
As of Android 3.1 the Android system will by default exclude all BroadcastReceiver from receiving
Intents if the corresponding application has never been started by the user or if the user explicitly stopped
the application via the Android menu (in Manage Application).
This is an additional security features as the user can be sure that only the applications he started will receive
broadcast Intents.
4. Intents as event triggers
Intents can also be used to send broadcast messages into the Android system.
BroadcastReceivers can register to event and will get notified if such an event is triggered.
Your application can register to system events, e.g. a new email has arrived, system boot is complete or a
phone call is received and react accordingly.
As said earlier, since Android version 3.1 the Android system will per default exclude all
BroadcastReceiver from receiving Intents if the corresponding application has never been started by
the user or if the user explicitly stopped the application via the Android menu (in Manage Application).
5. Share Intent and ShareActionProvider
As of Android 4.0 you can also add an Action Provider to your ActionBar which allows to share. For this you
have to define a special menu entry and assign an Intent which contain the sharing data to it in your
Activity.
<?xml version="1.0" encoding="utf-8"?><menu xmlns:android="http://schemas.android.com/apk/res/android" >
<item android:id="@+id/menu_share" android:title="Share" android:showAsAction="ifRoom" android:actionProviderClass="android.widget.ShareActionProvider" /> <item android:id="@+id/item1" android:showAsAction="ifRoom" android:title="More entries..."> </item>
</menu>
@Overridepublic boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.mymenu, menu); // provider is a field in your Activity provider = (ShareActionProvider) menu.findItem(R.id.menu_share) .getActionProvider(); setShareIntent();
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return true;}
public void setShareIntent() { Intent intent = new Intent(Intent.ACTION_SEND); intent.setType("text/plain"); intent.putExtra(Intent.EXTRA_TEXT, "Message"); provider.setShareIntent(intent);}
Unfortunately this does not seem to work in the Android emulator, see Bug report for details .
6. Finding out if an Intent is available
Sometimes you want to find if an application has registered for a certain Intent. For example you want to
check if a certain receiver is available and if you enable some functionality in your app.
This can be done via the PackageManager class. The following code checks if an someone has registered
himself for a certain Intent. Construct your Intent as you desired to trigger it and pass it to the following
method.
public static boolean isIntentAvailable(Context ctx, Intent intent) { final PackageManager mgr = ctx.getPackageManager(); List<ResolveInfo> list = mgr.queryIntentActivities(intent, PackageManager.MATCH_DEFAULT_ONLY); return list.size() > 0;}
Based on the result you can adjust your application for example you could disable or hide certan menu items.
7. Prerequisites for this tutorial
The following assumes that you have already basic knowledge in Android development. Please check the
Android development tutorial to learn the basics.
8. Tutorial: Explicit intents and data transfer
between activities
The following tutorial demonstrates how to use explicit Intents and how to transfer data between two
Activities.
The first Activity will call the second one via an explicit intent. Once the user select the "Back" button on
his phone the first Activity will receive some hard-coded data from the Sub-Activity.
Create a new Android application "de.vogella.android.intent.explicit" with the Activity called ActivityOne.
Change the layout main.xml to the following.
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" >
<TextView android:id="@+id/TextView01" android:layout_width="wrap_content" android:layout_height="wrap_content" android:minHeight="60dip" android:text="First Activity. Press button to call second activity" android:textSize="20sp" > </TextView>
<Button android:id="@+id/Button01" android:layout_width="wrap_content" android:layout_height="wrap_content" android:onClick="onClick" android:text="Calling an intent" > </Button>
</LinearLayout>
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Create the layout "second.xml".
<?xml version="1.0" encoding="utf-8"?><GridLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:alignmentMode="alignBounds" android:columnCount="2" android:columnOrderPreserved="false" android:useDefaultMargins="true" >
<TextView android:layout_gravity="center_horizontal" android:text="Input 1" android:textSize="32dip" />
<EditText android:id="@+id/input1" android:layout_gravity="fill_horizontal" android:text="Default" />
<TextView android:layout_gravity="center_horizontal" android:text="Input 2" android:textSize="32dip" />
<EditText android:id="@+id/input2" android:layout_gravity="fill_horizontal" android:text="Default" />
<Button android:layout_column="1" android:layout_gravity="right" android:width="80dp" android:onClick="onClick" android:text="Finish" />
</GridLayout>
Declare a new Activity called ActivityTwo via the AndroidManifest.xml file.
<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android" package="de.vogella.android.intent.explicit" android:versionCode="1" android:versionName="1.0" >
<uses-sdk android:minSdkVersion="15" />
<application android:icon="@drawable/icon" android:label="@string/app_name" > <activity android:name=".ActivityOne" 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="ActivityTwo" android:label="ActivityTwo" > </activity> </application>
</manifest>
Create the following coding for your two Activities.
package de.vogella.android.intent.explicit;
import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.widget.Toast;
public class ActivityOne extends Activity { private static final int REQUEST_CODE = 10;
/** Called when the activity is first created. */
@Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); }
public void onClick(View view) { Intent i = new Intent(this, ActivityTwo.class);
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i.putExtra("Value1", "This value one for ActivityTwo "); i.putExtra("Value2", "This value two ActivityTwo"); // Set the request code to any code you like, you can identify the // callback via this code startActivityForResult(i, REQUEST_CODE); }
@Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { if (resultCode == RESULT_OK && requestCode == REQUEST_CODE) { if (data.hasExtra("returnKey1")) { Toast.makeText(this, data.getExtras().getString("returnKey1"), Toast.LENGTH_SHORT).show(); } } }}
package de.vogella.android.intent.explicit;
import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.widget.EditText;
public class ActivityTwo extends Activity {
/** Called when the activity is first created. */
@Override public void onCreate(Bundle bundle) { super.onCreate(bundle); setContentView(R.layout.second); Bundle extras = getIntent().getExtras(); if (extras == null) { return; } String value1 = extras.getString("Value1"); String value2 = extras.getString("Value2"); if (value1 != null && value2 != null) { EditText text1 = (EditText) findViewById(R.id.input1); EditText text2 = (EditText) findViewById(R.id.input2); text1.setText(value1); text2.setText(value2); } }
public void onClick(View view) { finish(); }
@Override public void finish() { Intent data = new Intent(); // Return some hard-coded values data.putExtra("returnKey1", "Swinging on a star. "); data.putExtra("returnKey2", "You could be better then you are. "); setResult(RESULT_OK, data); super.finish(); }}
Run your application. The first will send data to the second Activity which will be shown on the user
interface. If you select back on your phone, the first Activity will display a Toast with the data from the
second Activity.
9. Tutorial: Implicit Intents
The following tutorial demonstrates the usage of implicit intents of the Android System.
Create a new Android application "de.vogella.android.intent.implicit" with a Activity called "
CallIntentsActivity ".
In this example we will use a Spinner to select the Intent which should get triggered. For the content of
the Spinner we will define static values.
Create the following "intents.xml" file in the "res/values" folder.
<resources> <string-array name="intents"> <item>Open Browser</item> <item>Call Someone</item> <item>Dial</item> <item>Show Map</item> <item>Search on Map</item> <item>Take picture</item> <item>Show contacts</item>
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<item>Edit first contact</item> </string-array> </resources>
Change the main.xml layout file to the following.
<?xml version="1.0" encoding="utf-8"?><GridLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:alignmentMode="alignBounds" android:columnCount="1" >
<Spinner android:id="@+id/spinner" android:layout_gravity="fill_horizontal" android:drawSelectorOnTop="true" > </Spinner> <Button android:id="@+id/trigger" android:onClick="onClick" android:text="Trigger Intent"> </Button>
</GridLayout>
To be able to use certain intents you need to register then for your application. Maintain the following
AndroidManifest.xml.
<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android" package="de.vogella.android.intent.implicit" android:versionCode="1" android:versionName="1.0" >
<uses-sdk android:minSdkVersion="15" />
<uses-permission android:name="android.permission.CALL_PRIVILEGED" > </uses-permission> <uses-permission android:name="android.permission.CALL_PHONE" > </uses-permission> <uses-permission android:name="android.permission.CAMERA" > </uses-permission> <uses-permission android:name="android.permission.READ_CONTACTS" > </uses-permission> <uses-permission android:name="android.permission.INTERNET"/>
<application android:icon="@drawable/icon" android:label="@string/app_name" > <activity android:name=".CallIntentsActivity" 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>
Change your activity to the following. We will start the new intent with the method startActivityForResult() which
allow us to specify a desired result code. Once the intent is finished the method onActivityResult() is called
and you can perform actions based on the result of the activity.
package de.vogella.android.intent.implicit;
import android.app.Activity;import android.content.Intent;import android.net.Uri;import android.os.Bundle;import android.view.View;import android.widget.ArrayAdapter;import android.widget.Spinner;import android.widget.Toast;
public class CallIntentsActivity extends Activity { private Spinner spinner;
/** Called when the activity is first created. */
@Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); spinner = (Spinner) findViewById(R.id.spinner); ArrayAdapter adapter = ArrayAdapter.createFromResource(this,
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R.array.intents, android.R.layout.simple_spinner_item); adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); spinner.setAdapter(adapter); }
public void onClick(View view) { int position = spinner.getSelectedItemPosition(); Intent intent = null; switch (position) { case 0: intent = new Intent(Intent.ACTION_VIEW, Uri.parse("http://www.vogella.com")); break; case 1: intent = new Intent(Intent.ACTION_CALL, Uri.parse("tel:(+49)12345789")); break; case 2: intent = new Intent(Intent.ACTION_DIAL, Uri.parse("tel:(+49)12345789")); startActivity(intent); break; case 3: intent = new Intent(Intent.ACTION_VIEW, Uri.parse("geo:50.123,7.1434?z=19")); break; case 4: intent = new Intent(Intent.ACTION_VIEW, Uri.parse("geo:0,0?q=query")); break; case 5: intent = new Intent("android.media.action.IMAGE_CAPTURE"); break; case 6: intent = new Intent(Intent.ACTION_VIEW, Uri.parse("content://contacts/people/")); break; case 7: intent = new Intent(Intent.ACTION_EDIT, Uri.parse("content://contacts/people/1")); break;
} if (intent != null) { startActivity(intent); } }
@Override public void onActivityResult(int requestCode, int resultCode, Intent data) { if (resultCode == Activity.RESULT_OK && requestCode == 0) { String result = data.toURI(); Toast.makeText(this, result, Toast.LENGTH_LONG); } }
}
If you start your application you should see an list of buttons and if you press the button, different activities
should be performed. Note that you didn't specify any receiving application only the thing that should be done.
10. Tutorial: Registering an IntentFilter
The following example will register a Activity for the Intent which is triggered to view a http webpage.
Our application downloads the HTML source of this page and display this in a TextView.
Create the Android project "de.vogella.android.intent.browserfilter" with the Activity called
BrowserActivity.
Register your Activity to the Intent via the Intent.Action_VIEW action and the scheme "http" via
the following AndroidManifest.xml. The manifest also declares the permission to access the Internet.
<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android" package="de.vogella.android.intent.browserfilter" android:versionCode="1" android:versionName="1.0" >
<uses-sdk android:minSdkVersion="15" />
<uses-permission android:name="android.permission.INTERNET" > </uses-permission>
<application android:icon="@drawable/icon" android:label="@string/app_name" > <activity android:name=".BrowserActivity" android:label="@string/app_name" >
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<intent-filter> <action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.DEFAULT" />
<data android:scheme="http" /> </intent-filter> </activity> </application>
</manifest>
Change the main.xml layout file to the following.
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" ><TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/textView"/></LinearLayout>
Install your application. If you now trigger an Intent to open an URL your should be able to select your own
component. You can for example trigger this Intent via the example from the implicit tutorials.
package de.vogella.android.intent.browserfilter;
import java.io.BufferedReader;import java.io.InputStreamReader;import java.net.URL;
import android.app.Activity;import android.content.Intent;import android.net.Uri;import android.os.Bundle;import android.os.StrictMode;import android.widget.TextView;
public class BrowserActivity extends Activity { /** Called when the activity is first created. */
@Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState);
// To keep this example simple, we allow network access // in the user interface thread StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder() .permitAll().build(); StrictMode.setThreadPolicy(policy);
setContentView(R.layout.main); Intent intent = getIntent(); TextView text = (TextView) findViewById(R.id.textView); // To get the action of the intent use String action = intent.getAction(); if (action != Intent.ACTION_VIEW) { throw new RuntimeException("Should not happen"); } // To get the data use Uri data = intent.getData(); URL url; try { url = new URL(data.getScheme(), data.getHost(), data.getPath()); BufferedReader rd = new BufferedReader(new InputStreamReader(url.openStream())); String line = ""; while ((line = rd.readLine()) != null) { text.append(line); }
} catch (Exception e) { e.printStackTrace(); }
}}
If you select you component the HTML code should be loaded into your text view.
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11. Tutorial: Picking an Image via Intent
The following example will show how to pick an Image from the phone app on Android via an Intent.
Create the Android project "de.vogella.android.imagepick" with the Activity called ImagePickActivity.
Change the main.xml layout file to the following.
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" >
<Button android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:onClick="pickImage" android:text="Button" > </Button>
<ImageView android:id="@+id/result" android:layout_width="match_parent" android:layout_height="match_parent" android:src="@drawable/icon" > </ImageView>
</LinearLayout>
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Change your Activity according to the following coding.
package de.vogella.android.imagepick;
import java.io.FileNotFoundException;import java.io.IOException;import java.io.InputStream;
import android.app.Activity;import android.content.Intent;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.os.Bundle;import android.view.View;import android.widget.ImageView;
public class ImagePickActivity extends Activity { private static final int REQUEST_CODE = 1; private Bitmap bitmap; private ImageView imageView;
/** Called when the activity is first created. */
@Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); imageView = (ImageView) findViewById(R.id.result); }
public void pickImage(View View) { Intent intent = new Intent(); intent.setType("image/*"); intent.setAction(Intent.ACTION_GET_CONTENT); intent.addCategory(Intent.CATEGORY_OPENABLE); startActivityForResult(intent, REQUEST_CODE); }
@Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { InputStream stream = null; if (requestCode == REQUEST_CODE && resultCode == Activity.RESULT_OK) try { // We need to recyle unused bitmaps if (bitmap != null) { bitmap.recycle(); } stream = getContentResolver().openInputStream(data.getData()); bitmap = BitmapFactory.decodeStream(stream);
imageView.setImageBitmap(bitmap); } catch (FileNotFoundException e) { e.printStackTrace(); } finally { if (stream != null) try { stream.close(); } catch (IOException e) { e.printStackTrace(); } } super.onActivityResult(requestCode, resultCode, data); }}
If you run this application you can select an Image from your Image Library and assign it to your ImageView.
12. Thank you
Please help me to support this article:
13. Questions and Discussion
Before posting questions, please see the vogella FAQ. If you have questions or find an error in this article
please use the www.vogella.com Google Group. I have created a short list how to create good
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questions which might also help you.
14. Links and Literature
14.1. Source Code
Source Code of Examples
14.2. Android Resources
Android Location API and Google Maps
Android and Networking
Android Homepage
Android Issues / Bugs
Android Google Groups
14.3. vogella Resources
vogella Training Android and Eclipse Training from the vogella team
Android Tutorial Introduction to Android Programming
GWT Tutorial Program in Java and compile to JavaScript and HTML
Eclipse RCP Tutorial Create native applications in Java
JUnit Tutorial Test your application
Git Tutorial Put everything you have under distributed version control system