外部应用无法调用“BroadCastReceiver”的onReceive方法。

要让外部应用调用BroadcastReceiver的onReceive方法，可以使用动态注册的方式注册BroadcastReceiver。以下是一个示例代码：

1. 在应用的AndroidManifest.xml文件中声明BroadcastReceiver的类名和接收的广播类型：

<receiver android:name=".MyBroadcastReceiver">
    <intent-filter>
        <action android:name="com.example.MY_BROADCAST" />
    </intent-filter>
</receiver>

2. 在应用的MainActivity.java文件中动态注册BroadcastReceiver：

public class MainActivity extends AppCompatActivity {
    private MyBroadcastReceiver receiver;
    private IntentFilter filter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        // 创建BroadcastReceiver实例
        receiver = new MyBroadcastReceiver();
        
        // 创建IntentFilter并添加广播类型
        filter = new IntentFilter();
        filter.addAction("com.example.MY_BROADCAST");
        
        // 动态注册BroadcastReceiver
        registerReceiver(receiver, filter);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        // 在Activity销毁时取消注册BroadcastReceiver
        unregisterReceiver(receiver);
    }
}

3. 创建BroadcastReceiver类并实现onReceive方法：

public class MyBroadcastReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        // 处理接收到的广播
        String message = intent.getStringExtra("message");
        Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
    }
}

通过以上步骤，你可以实现在外部应用中调用BroadcastReceiver的onReceive方法。