Implicit intent, intent

Implicit intent, intent
Implicit intent

1. Introduction to implicit intent

 

Explicit intent we mentioned earlier, such:

Intent intent = new Intent ();

Intent. setClass (this, Other. class); // this sentence indicates an explicit intent, because it explicitly sets the activation object to an Other class.

StartActivity (intent );

 

As the name implies, the implicit intention is to find the most matched component without explicitly setting the activation object. For example, five people:

(1) A: 170

(2) B: 160

3) C: 180

(4) D: 190

(5) E: 200

If it is explicit, if we want to specify A, it will say, "I chose. ", but if it is an implicit intention, it will say:" I want to select 170cm people ". Although it does not specify to select A, it will find the person with the most matching conditions.

 

In the intent filter, matching conditions similar to the "height" condition in the preceding example include:

(1) action

(2) category

(3) data: scheme, host, path, type

When the conditions for activating components are set in the program, the program will look for the most matched components, but note: as long as there is a bit of mismatch, it will not match;

For example:

Intent intent = new Intent ();

Intent. setAction ("a"); // This sentence only specifies the Action

StartActivity (intent); // find the most matched component for activation. intent. addCategory ("Android. intent. category. DEFAULT") is called internally ");

 

Reference: http://blog.csdn.net/xiazdong/article/details/7764865

 

Ii. code example

Com. example. implicit2a_Intent.MainActivity

Package com. example. implicit2a_Intent; import com. example. implicit2_intent.R; import android. app. activity; import android. content. dialogInterface; import android. content. intent; import android. OS. bundle; import android. view. view; import android. view. view. onClickListener; import android. widget. button; public class MainActivity extends Activity implements OnClickListener {private Button btn_one; @ Override protected void onCreate (Bundle savedInstanceState) {// TODO Auto-generated method stub super. onCreate (savedInstanceState); setContentView (R. layout. activity_main); btn_one = (Button) findViewById (R. id. button1); btn_one.setOnClickListener (this) ;}@ Override public void onClick (View v) {// TODO Auto-generated method stub Intent intent = new Intent (); /*** find all actions that match "com. fry. activity01 "page * also finds all Category android. intent. category. DEFAULT Page * String android. content. intent. CATEGORY_DEFAULT = * "android. intent. category. DEFAULT "*/intent. setAction ("com. fry. activity01 "); intent. addCategory (Intent. CATEGORY_DEFAULT); startActivity (intent );}}

/Implicit2_Intent/AndroidManifest. xml

 1 <manifest xmlns:android="http://schemas.android.com/apk/res/android" 2     package="com.example.implicit2_intent" 3     android:versionCode="1" 4     android:versionName="1.0" > 5  6     <uses-sdk 7         android:minSdkVersion="8" 8         android:targetSdkVersion="19" /> 9 10     <application11         android:allowBackup="true"12         android:icon="@drawable/ic_launcher"13         android:label="@string/app_name"14         android:theme="@style/AppTheme" >15         <activity16             android:name="com.example.implicit2a_Intent.MainActivity"17             android:label="@string/app_name" >18             <intent-filter>19                 <action android:name="android.intent.action.MAIN" />20 21                 <category android:name="android.intent.category.LAUNCHER" />22             </intent-filter>23         </activity>24         <activity android:name="com.example.implicit2a_Intent.Activity03">25             <intent-filter >26                 <action android:name="com.fry.activity01"></action>27                 <category android:name="android.intent.category.DEFAULT"/>28             </intent-filter>29         </activity>30     </application>31 32 </manifest>

Another Application

Com. example. implicit1Intent. MainActivity

1 package com. example. implicit1Intent; 2 3 4 import com. example. implicitintent. r; 5 6 import android. app. activity; 7 import android. content. dialogInterface; 8 import android. content. intent; 9 import android. OS. bundle; 10 import android. view. view; 11 import android. view. view. onClickListener; 12 import android. widget. button; 13 14 public class MainActivity extends Activity implements OnClickListener {15 private Button btn_one; 16 @ Override17 protected void onCreate (Bundle savedInstanceState) {18 // TODO Auto-generated method stub19 super. onCreate (savedInstanceState); 20 setContentView (R. layout. activity_main); 21 btn_one = (Button) findViewById (R. id. button1); 22 btn_one.setOnClickListener (this); 23} 24 @ Override25 public void onClick (View v) {26 // TODO Auto-generated method stub27 Intent intent = new Intent (); 28/** 29 * Find all actions as "com. fry. activity01 "page 30 * also finds that all Category is android. intent. category. DEFAULT Page 31 * String android. content. intent. CATEGORY_DEFAULT = 32 * "android. intent. category. DEFAULT "33 */34 intent. setAction ("com. fry. activity01 "); 35 intent. addCategory (Intent. CATEGORY_DEFAULT); 36 startActivity (intent); 37} 38 39 40}

/Implicit_Intent/AndroidManifest. xml

 1 <manifest xmlns:android="http://schemas.android.com/apk/res/android" 2     package="com.example.implicitintent" 3     android:versionCode="1" 4     android:versionName="1.0" > 5  6     <uses-sdk 7         android:minSdkVersion="8" 8         android:targetSdkVersion="19" /> 9 10     <application11         android:allowBackup="true"12         android:icon="@drawable/ic_launcher"13         android:label="@string/app_name"14         android:theme="@style/AppTheme" >15         <activity16             android:name="com.example.implicit1Intent.MainActivity"17             android:label="@string/app_name" >18             <intent-filter>19                 <action android:name="android.intent.action.MAIN" />20 21                 <category android:name="android.intent.category.LAUNCHER" />22             </intent-filter>23         </activity>24         <activity android:name="com.example.implicit1Intent.Activity01">25             <intent-filter >26                 <action android:name="com.fry.activity01"></action>27                 <category android:name="android.intent.category.DEFAULT"/>28             </intent-filter>29         </activity>30         <activity android:name="com.example.implicit1Intent.Activity02">31             <intent-filter >32                 <action android:name="com.fry.activity01"></action>33                 <category android:name="android.intent.category.DEFAULT"/>34             </intent-filter>35         </activity>36     </application>37 38 </manifest>