#Androdi training# interactions with activities or apps

一  to Other's Apps

explicit intent

Intent mIntent = new Intent();mIntent.setClass(this,MainConversationActivity.class);startActivity(mIntent);

implicit intent

call:

Uri number = Uri.parse("tel:[phone]");Intent callIntent = new Intent(Intent.ACTION_DIAL, number);

map:

// Map point based on addressUri location = Uri.parse("geo:0,0?q=1600+Amphitheatre+Parkway,+Mountain+View,+California");// Or map point based on latitude/longitude// Uri location = Uri.parse("geo:37.422219,-122.08364?z=14"); // z param is zoom levelIntent mapIntent = new Intent(Intent.ACTION_VIEW, location);

view a page

Uri webpage = Uri.parse("http://www.android.com");Intent webIntent = new Intent(Intent.ACTION_VIEW, webpage);

tips:

1.you can add more data through putExtra()

2.if you don't include a Uri in the intent, you should usually use setType() to specify the type of data

associated with the intent.

send an email with an attachment

Intent emailIntent = new Intent(Intent.ACTION_SEND);// The intent does not have a URI, so declare the "text/plain" MIME typeemailIntent.setType(HTTP.PLAIN_TEXT_TYPE);emailIntent.putExtra(Intent.EXTRA_EMAIL, new String[] {"[e-mail]"}); // recipientsemailIntent.putExtra(Intent.EXTRA_SUBJECT, "Email subject");emailIntent.putExtra(Intent.EXTRA_TEXT, "Email message text");emailIntent.putExtra(Intent.EXTRA_STREAM, Uri.parse("content://path/to/email/attachment"));// You can also attach multiple items by passing an ArrayList of Uris

create a calendar event

Intent calendarIntent = new Intent(Intent.ACTION_INSERT, Events.CONTENT_URI);Calendar beginTime = Calendar.getInstance().set(2012, 0, 19, 7, 30);Calendar endTime = Calendar.getInstance().set(2012, 0, 19, 10, 30);calendarIntent.putExtra(CalendarContract.EXTRA_EVENT_BEGIN_TIME, beginTime.getTimeInMillis());calendarIntent.putExtra(CalendarContract.EXTRA_EVENT_END_TIME, endTime.getTimeInMillis());calendarIntent.putExtra(Events.TITLE, "Ninja class");calendarIntent.putExtra(Events.EVENT_LOCATION, "Secret dojo");

3.you may need to verify if there is an app to receive the intent

PackageManager packageManager = getPackageManager();List activities = packageManager.queryIntentActivities(intent,        PackageManager.MATCH_DEFAULT_ONLY);boolean isIntentSafe = activities.size() > 0;

if(isIntentSafe){ startActivity(mapIntent);}

4. show the chooser

Intent intent = new Intent(Intent.ACTION_SEND);...// Always use string resources for UI text.// This says something like "Share this photo with"String title = getResources().getString(R.string.chooser_title);// Create intent to show chooserIntent chooser = Intent.createChooser(intent, title);// Verify the intent will resolve to at least one activityif (intent.resolveActivity(getPackageManager()) != null) {    startActivity(chooser);}

二  getting a Result from an Activity

startActivityForResult()

onActivityResult()

static final int PICK_CONTACT_REQUEST = 1;  // The request code. Later, you app can properly identify the result and determine how to handle it....private void pickContact() {    Intent pickContactIntent = new Intent(Intent.ACTION_PICK, Uri.parse("content://contacts"));    pickContactIntent.setType(Phone.CONTENT_TYPE); // Show user only contacts w/ phone numbers    startActivityForResult(pickContactIntent, PICK_CONTACT_REQUEST);}

@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {    // Check which request we're responding to    if (requestCode == PICK_CONTACT_REQUEST) {        // Make sure the request was successful        if (resultCode == RESULT_OK) {            // The user picked a contact.            // The Intent's data Uri identifies which contact was selected.            // Do something with the contact here (bigger example below)        }    }}

@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {    // Check which request it is that we're responding to    if (requestCode == PICK_CONTACT_REQUEST) {        // Make sure the request was successful        if (resultCode == RESULT_OK) {            // Get the URI that points to the selected contact            Uri contactUri = data.getData();            // We only need the NUMBER column, because there will be only one row in the result            String[] projection = {Phone.NUMBER};            // Perform the query on the contact to get the NUMBER column            // We don't need a selection or sort order (there's only one result for the given URI)            // CAUTION: The query() method should be called from a separate thread to avoid blocking            // your app's UI thread. (For simplicity of the sample, this code doesn't do that.)            // Consider using CursorLoader to perform the query.            Cursor cursor = getContentResolver()                    .query(contactUri, projection, null, null, null);            cursor.moveToFirst();            // Retrieve the phone number from the NUMBER column            int column = cursor.getColumnIndex(Phone.NUMBER);            String number = cursor.getString(column);            // Do something with the phone number...        }    }}

三 allwoing other apps to start your activity

<intent-filter>

Action:<action>

ACTION_SEND

ACTION_VIEW

Data:<data>

A description of the data associated with the intent.

you can specify the MIME type

Note: if you don't need to declare specifics about data Uri(such as when your activity handles to other kind of "extra")

 data, instead of a Uri), you should specify only the android:mimeType attribute to declare the type of data, such as text/plain or image/jpeg

Category:<category>

rarely used.

<activity android:name="ShareActivity">    <intent-filter>        <action android:name="android.intent.action.SEND"/>        <category android:name="android.intent.category.DEFAULT"/>        <data android:mimeType="text/plain"/>        <data android:mimeType="image/*"/>    </intent-filter></activity>

<activity android:name="ShareActivity">    <!-- filter for sending text; accepts SENDTO action with sms URI schemes -->    <intent-filter>        <action android:name="android.intent.action.SENDTO"/>        <category android:name="android.intent.category.DEFAULT"/>        <data android:scheme="sms" />        <data android:scheme="smsto" />    </intent-filter>    <!-- filter for sending text or images; accepts SEND action and text or image data -->    <intent-filter>        <action android:name="android.intent.action.SEND"/>        <category android:name="android.intent.category.DEFAULT"/>        <data android:mimeType="image/*"/>        <data android:mimeType="text/plain"/>    </intent-filter></activity>

handle the Intent

@Overrideprotected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.main);    // Get the intent that started this activity    Intent intent = getIntent();    Uri data = intent.getData();    // Figure out what to do based on the intent type    if (intent.getType().indexOf("image/") != -1) {        // Handle intents with image data ...    } else if (intent.getType().equals("text/plain")) {        // Handle intents with text ...    }}

return a result

when your operation is done and the user should returen original activity, call finish() to close (and destroy) your activity.

Intent result = new Intent("com.example.RESULT_ACTION", Uri.parse("content://result_uri"));setResult(Activity.RESULT_OK, result);finish();

the default is RESULT_CANCELED.

setResult(RESULT_COLOR_RED);finish();

the intent is not necessary.