详细介绍：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">
<application
  android:allowBackup="true"
  android:icon="@mipmap/ic_launcher"
  android:label="@string/app_name">
<!-- 发送广播的Activity -->
  <activity
    android: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";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button sendButton = findViewById(R.id.send_button);
sendButton.setOnClickListener(new View.OnClickListener() {
@Override
public 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">
<application
  android:allowBackup="true"
  android:icon="@mipmap/ic_launcher"
  android:label="@string/app_name">
<!-- 接收广播的Activity -->
  <activity
    android: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";
@Override
public 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Toast
Toast.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;
@Override
protected 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">
  <TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Sender App"
    android:textSize="24sp"
    android:layout_marginBottom="32dp" />
  <Button
    android: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">
  <TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Receiver App"
    android:textSize="24sp"
    android:layout_marginBottom="32dp" />
  <TextView
    android: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：

1. 导出：接收广播的组件必须设置 android:exported="true"
2. 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
3. 权限：根据需要添加适当的权限声明
4. 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。