Android Intent and four components

<span id="Label3"></p><p><br>Intent Intent<br><br><br>I. Explicit intent<br>Directly specify the class to Implement:<br>Intent intent=new Intent (mainactivity.this,xxx.class);<br>This.startactivity (intent);<br><br>Ii. Implicit Intent<br>1:xml Configuration: Adds an attribute <intent-filter></intent-filter&gt to the configuration of the class to which the intent is directed, such as:<br><activity<br>Android:name= "com.example.activity.twoActivity"<br>Android:label= "the other"<br><intent-filter><br><action android:name= "com.xxx.xxxx"/><br><data android:mimetype= "text/string"/><br><category android:name= "android.intent.category.DEFAULT"/><br></intent-filter><br>Android:launchmode= "singleinstance"/><br><br>2: use in form activity:<br>Intent Intent =new Intent ();<br>Intent.setaction ("com.xxxx.xxxx");<br>Intent.settype ("text/string");<br>Intent.addcategory (Intent.CATEGORY.DEFAULT);<br>This.startactivity (intent)<br><br>Note: in implicit intent, multiple actions/classes can be used at the same time, and will be automatically selected for the user at Startup.<br><br><br>Four components: Activity, contentprovider, broadcastreceive, Service<br><br> <br>first, Activity Form<br><br>1. Life cycle<br>1.onCreate () is called when the form is created<br>2.onStart () called when the form interface is visible<br>3.onResume () Called when the user gets focus<br>4.onPause () is called when it loses focus<br>5.onStop () is called when the form interface is not visible<br>6.onDestory () is called when the form is destroyed<br>7.onRestart Restart Form<br>Open form:<br>Minimized: 4-5<br>Recover form Size: 7-2-3<br>Close Form: 4-5-6<br><br>2. Screen switching<br><activity android:configchanges= "orentagion|keyboardhidden|screensize"--window change does not reset<br>android:screenorentation= "landscape"---set the window orientation, default Auto-sensing. Landscape: Landscape.<br><br>3. Activation mode of activity<br><activity launchmode= ""<br>Standard: default mode<br>Singletop: If the activity is at the top, the system will not be Recreated. instead, the Onnewintent method of the current activity is Called.<br>Singletask: keep the task stack with only one activity, if the activity you want to start already exists, it will reuse existing activity and clear all the windows on the Activity.<br>Singinstance: There is only one activity in the entire System. it runs on a self-contained task stack, and only one instance of the task stack exists<br><br>Ii. ContentProvider content providers<br><br>third, Broadcastreceiver Broadcast Recipients<br><br>1, the orderly broadcast ———— all can accept, can not be modified can not be intercepted.<br>1. Send the broadcast<br>public void Sendbroadcast (view View) {<br>Intent Intent =new Intent ();<br>Intent.setaction ("com.xxx.xxxx");<br>This.sendbroadcast (intent);<br>}<br><br>2. Receiving broadcasts<br>Configuration file:<br><activity><br></activity><br><receiver android:name= "com.xxxx.xxxxx" >--broadcast Name<br><intent-filter><br><action android:name= "xxxxxx"/>--detection Object name<br></intent-filter><br></receiver><br><br>Broadcast. Java files:<br>Inherit Broadcastreceiver<br><br>Data and modifications can be obtained (not referring to broadcast Content)<br>For Example: Call<br>This.getresultdata (); Get the Caller's outgoing call<br>This.setresultdata ("xxx"); Modify the Caller's outgoing call<br><br>2, Disorderly Broadcasting —————— a first-level downward transmission, can be modified to intercept broadcast Content.<br>1. Orderly broadcast<br>Intent Intent =new Intent ();<br>Intent.setaction ("com.xxx.xxxx");<br>This.sendorderedbroadcast (intent,recriverpermission,resultreceiver,scheduler,initialcode,initialdata, initialextras);<br>Such as: this.sendorderedbroadcast (intent,null,null,null, "400", "broadcast content", null);<br><br>2. Receive ordered broadcasts<br>Configuration file:<br><activity><br></activity><br><receiver android:name= "com.xxxx.xxxxx3" >--broadcast Name<br><intent-filter android:priority= "" ">----representative level, The first to receive a large number<br><action android:name= "xxxxxx"/>--detection Object name<br></intent-filter><br></receiver><br><receiver android:name= "com.xxxx.xxxxx2" >--broadcast Name<br><intent-filter android:priority= ">"<br><action android:name= "xxxxxx"/>--detection Object name<br></intent-filter><br></receiver><br><br>Broadcast. Java files:<br>Inherit Broadcastreceiver<br>This.getresultdata (); Get broadcast Content<br>This.setresultdata ("xxx"); Modify broadcast Content<br>This.abortbroadcast (); Intercept Stop broadcast<br><br><br>Iv. Service Services<br>------a component (class) running in the background<br><br>1. Priority levels for processes and processes<br>The process ———— an Application.<br>Priority: High-to-low<br>1.Foreground process that the foreground process user is using<br>2.visible process visible processes can be seen by processes (E.G. floating Windows)<br>3.service Process Service process with background service<br>4.background process background process minimized but not closed<br>5.Empty process does not have any activity (the return key has been returned to the DESKTOP)<br><br>2. Service life cycle<br>OnCreate () is called when it is created<br>Called when Onstartcommand () is enabled<br>Ondestory () is called when it is destroyed<br><br>3. Use<br>1. Create<br>New Java Inheritance Service<br>Configuration file:<br><service android:name= "com.xxx.xxx" ></service><br>2. use<br>Enabled: (if The service does not exist, create a service and then turn it On)<br>Intent intent=new Intent (mainactivity.this,xxxx.cladss);<br>This.startservice (intent);<br>Shut down:<br>Intent intent=new Intent (mainactivity.this,xxxx.class);<br>This.stopservice (intent);</p><p><p>Android Intent and four components</p></p></span>