android单双页模式 android的广播接收器BroadcastReceiver android(本地广播 标准广播 有序广播)
2017/3/8 记载
另外值得注意的是这种敏感性操作android是需要权限的，需要在AndroidManifest.xml中注册生命 静态注册： <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.ldp.com.broadcastreceiverproject"> <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/><!--网络权限--> <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/><!--监听系统开机--> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:supportsRtl="true" android:theme="@style/AppTheme"> <activity android:name=".MainActivity"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <!--静态注册才会出现receiver标签来注册权限，而动态注册是不需要的。只需要在上面标注一下--> <receiver android:name=".BBootCompleteReceiver" android:enabled="true" android:exported="true"> <intent-filter> <action android:name="android.intent.action.BOOT_COMPLETED"/> </intent-filter> </receiver> </application> </manifest> 注意: 广播中的 onReceive()方法不要写过多的逻辑或者耗时的语句，在广播接收器汇总是不允许开启线程的。
新建一个广播类MyBroadcastReceiver
package com.example.ldp.com.broadcastreceiverproject; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.util.Log; import android.widget.Toast; public class MyBroadcastReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { // TODO: This method is called when the BroadcastReceiver is receiving Toast.makeText(context,"AAAAA GetMyBroadcastReceiver",Toast.LENGTH_SHORT).show(); Log.d(MainActivity.ACTIVITY_SERVICE,"成功接收"); } } 这个时候的注册信息就会自动加载到AndroidMainfest.xml中 <receiver android:name=".MyBroadcastReceiver" android:enabled="true" android:exported="true"> <intent-filter> <action android:name="com.example.ldp.com..MY_BROADCAST"/> <!--这个是随便写的相当于口令--> </intent-filter> 修改activity_main.xml 用按钮点击发送广播 <?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"> <Button android:id="@+id/button" android:text="Send Broadcast" android:layout_width="match_parent" android:layout_height="wrap_content" /> </LinearLayout> 修改MainActivity package com.example.ldp.com.broadcastreceiverproject; import android.content.Intent; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.util.Log; import android.view.View; import android.widget.Button; public class MainActivity extends AppCompatActivity{ @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Button button = (Button)findViewById(R.id.button); button.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent intent = new Intent("com.example.ldp.com..MY_BROADCAST"); sendBroadcast(intent);//发送标准广播 Log.d(MainActivity.ACTIVITY_SERVICE,"成功发送"); } }); } } 运行点击一下按钮是不是会接收到广播呢？那情况又来了，看看下面 新建MyBroadcastReceiverProject2新建AnotherBroadcastReceiver广播类
package com.example.ldp.com.broadcastreceiverproject2; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.widget.Toast; public class AnotherBroadcastReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { // TODO: This method is called when the BroadcastReceiver is receiving // an Intent broadcast. Toast.makeText(context,"sdsdsdsdsd",Toast.LENGTH_SHORT).show(); } } 修改AndroidMainfest.xml文件，其实就跟上面一样的(口令) <receiver android:name=".AnotherBroadcastReceiver" android:enabled="true" android:exported="true"> <intent-filter> <action android:name="com.example.ldp.com..MY_BROADCAST"/> </intent-filter> </receiver> 再运行安装，回到上一个项目，点击按钮，是不是会出现两次提示消息呢，很明显这是两个程序两个apk文件才对 说明我们的标准广播是可以扩进程(前提是要有网络，个人认为)来接收广播的。这儿例子就证明了应用程序发出的广播是可以被其他应用程序接收到的。
修改MainActivity
protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Button button = (Button)findViewById(R.id.button); button.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent intent = new Intent("com.example.ldp.com..MY_BROADCAST"); /*sendBroadcast(intent);//发送标准广播*/ sendOrderedBroadcast(intent,null);//发送有序广播，第二个参数是和权限有关的 Log.d(MainActivity.ACTIVITY_SERVICE,"成功发送"); } }); } 这个时候运行一下程序，发现两个程序仍然可以收到这条广播，这是咋回事儿啊？不是改成有序了嘛？ 不过这个时候的广播器是有先后顺序，我们再AndroidMainfest.xml中修改它的优先级priority <receiver android:name=".MyBroadcastReceiver" android:enabled="true" android:exported="true"> <intent-filter android:priority="100"> <!--设置为100保证在其他之前收到这个广播--> <action android:name="com.example.ldp.com..MY_BROADCAST"/> </intent-filter> </receiver> 而且广播是可以 截断的，这样后面的应用都接收不到了，更保证了广播的 安全性(这个还是要靠本地广播，后面内容)。 修改MyBroadcastReceiver package com.example.ldp.com.broadcastreceiverproject; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.util.Log; import android.widget.Toast; public class MyBroadcastReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { // TODO: This method is called when the BroadcastReceiver is receiving Toast.makeText(context,"AAAAA GetMyBroadcastReceiver",Toast.LENGTH_SHORT).show(); Log.d(MainActivity.ACTIVITY_SERVICE,"成功接收"); abortBroadcast();//截断广播 } }
