高版本Android跨应用广播通信实例
在高版本的Android上，应用间发送广播需要特别注意权限和导出设置。以下是完整的发送和接收广播的代码示例：
1. 发送广播的应用
AndroidManifest.xml 配置
<manifest xmlns:android="http://schemas.android.com/apk/res/android"package="com.example.sender"><applicationandroid:allowBackup="true"android:icon="@mipmap/ic_launcher"android:label="@string/app_name"><!-- 发送广播的Activity --><activityandroid:name=".MainActivity"android:exported="true"><intent-filter><action android:name="android.intent.action.MAIN" /><category android:name="android.intent.category.LAUNCHER" /></intent-filter></activity></application>
</manifest>
MainActivity.java
package com.example.sender;import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;public class MainActivity extends AppCompatActivity {private static final String CUSTOM_ACTION = "com.example.CUSTOM_BROADCAST";@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);Button sendButton = findViewById(R.id.send_button);sendButton.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {sendCustomBroadcast();}});}private void sendCustomBroadcast() {Intent intent = new Intent(CUSTOM_ACTION);// 添加接收应用的包名，提高安全性（必要，注意是接收应用的包名，不是发送应用的包名）intent.setPackage("com.example.receiver");// 传递数据intent.putExtra("message", "Hello from sender app!");intent.putExtra("timestamp", System.currentTimeMillis());try {// 发送广播sendBroadcast(intent);Toast.makeText(this, "Broadcast sent successfully", Toast.LENGTH_SHORT).show();} catch (Exception e) {Toast.makeText(this, "Failed to send broadcast: " + e.getMessage(), Toast.LENGTH_SHORT).show();}}
}
2. 接收广播的应用
AndroidManifest.xml 配置
<manifest xmlns:android="http://schemas.android.com/apk/res/android"package="com.example.receiver"><applicationandroid:allowBackup="true"android:icon="@mipmap/ic_launcher"android:label="@string/app_name"><!-- 接收广播的Activity --><activityandroid:name=".MainActivity"android:exported="true"><intent-filter><action android:name="android.intent.action.MAIN" /><category android:name="android.intent.category.LAUNCHER" /></intent-filter></activity><!-- 注册BroadcastReceiver exported必须设置为 true --><receiver android:name=".CustomBroadcastReceiver"android:exported="true"android:enabled="true"><intent-filter><action android:name="com.example.CUSTOM_BROADCAST" /></intent-filter></receiver></application>
</manifest>
CustomBroadcastReceiver.java
package com.example.receiver;import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
import android.widget.Toast;public class CustomBroadcastReceiver extends BroadcastReceiver {private static final String TAG = "CustomBroadcastReceiver";@Overridepublic void onReceive(Context context, Intent intent) {if (intent != null && "com.example.CUSTOM_BROADCAST".equals(intent.getAction())) {// 获取传递的数据String message = intent.getStringExtra("message");long timestamp = intent.getLongExtra("timestamp", 0);Log.d(TAG, "Received broadcast: " + message + ", timestamp: " + timestamp);// 显示通知或ToastToast.makeText(context, "Received: " + message, Toast.LENGTH_LONG).show();// 可以启动Activity或Service来处理数据Intent activityIntent = new Intent(context, MainActivity.class);activityIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);activityIntent.putExtra("received_message", message);context.startActivity(activityIntent);}}
}
MainActivity.java (接收应用的主Activity)
package com.example.receiver;import android.os.Bundle;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;public class MainActivity extends AppCompatActivity {private TextView messageTextView;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);messageTextView = findViewById(R.id.message_text);// 检查是否有从广播传递过来的消息String receivedMessage = getIntent().getStringExtra("received_message");if (receivedMessage != null) {messageTextView.setText("Received message: " + receivedMessage);}}
}
3. 布局文件
发送应用的 activity_main.xml
<?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"android:padding="16dp"><TextViewandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:text="Sender App"android:textSize="24sp"android:layout_marginBottom="32dp" /><Buttonandroid:id="@+id/send_button"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="Send Broadcast" /></LinearLayout>
接收应用的 activity_main.xml
<?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"android:padding="16dp"><TextViewandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:text="Receiver App"android:textSize="24sp"android:layout_marginBottom="32dp" /><TextViewandroid:id="@+id/message_text"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="Waiting for broadcast..."android:textSize="16sp" /></LinearLayout>
4. 安全注意事项
使用权限保护（可选）
如果需要更高级别的安全保护，可以添加自定义权限：
在接收应用的 AndroidManifest.xml 中添加：
<permission android:name="com.example.receiver.CUSTOM_PERMISSION"android:protectionLevel="signature" /><uses-permission android:name="com.example.receiver.CUSTOM_PERMISSION" />
在发送应用中：
<uses-permission android:name="com.example.receiver.CUSTOM_PERMISSION" />
在发送广播时：
intent.putExtra("message", "Hello from sender app!");
sendBroadcast(intent, "com.example.receiver.CUSTOM_PERMISSION");
关键要点：
- 导出：接收广播的组件必须设置
android:exported="true" - 安全性：使用特定的包名和自定义Action来避免广播被其他应用拦截
- 权限：根据需要添加适当的权限声明
- Intent Filter：确保发送和接收的Action字符串完全匹配
这样配置后，两个应用就可以在Android高版本上正常发送和接收广播了。