向广播接收器发送隐式意图

Question

我正在尝试创建 2 个应用程序。第一个应用程序通过使用 sendBroadcast 的隐式意图发送 imei。下面是第一个应用程序的代码。

package com.example.activity_1;

import android.Manifest;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Build;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.telephony.SubscriptionManager;
import android.telephony.TelephonyManager;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    TextView tv_imei;

    Button bt_getimei;
    String imei;

    public static ArrayList<String> numbers;
    private SubscriptionManager subscriptionManager;
    static final Integer PHONESTATS = 0x1;
    private final String TAG = MainActivity.class.getSimpleName();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        tv_imei = (TextView) findViewById(R.id.tv_imei);

        bt_getimei = (Button) findViewById(R.id.bt_getimei);


        numbers = new ArrayList<String>();
        subscriptionManager = SubscriptionManager.from(MainActivity.this);

        bt_getimei.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                askForPermission(Manifest.permission.READ_PHONE_STATE, PHONESTATS);

                tv_imei.setText(imei);

                Intent sendImei = new Intent();
                sendImei.addFlags(sendImei.FLAG_INCLUDE_STOPPED_PACKAGES);
                sendImei.setAction("com.example.activity_1");
                sendImei.putExtra(Intent.EXTRA_TEXT, imei);
                sendImei.setType("text/plain");
                sendBroadcast(sendImei);

            }
        });

    }
private void askForPermission(String permission, Integer requestCode) {
    if (ContextCompat.checkSelfPermission(MainActivity.this, permission) != PackageManager.PERMISSION_GRANTED) {

        // Should show an explanation
        if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, permission)) {

            ActivityCompat.requestPermissions(MainActivity.this, new String[]{permission}, requestCode);

        } else {

            ActivityCompat.requestPermissions(MainActivity.this, new String[]{permission}, requestCode);
        }
    } else {
        imei = getImeiNumber();


        Toast.makeText(this, permission + " is already granted.", Toast.LENGTH_SHORT).show();
    }
}


@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    switch (requestCode) {
        case 1: {

            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                imei = getImeiNumber();


            } else {

                Toast.makeText(MainActivity.this, "You have Denied the Permission", Toast.LENGTH_SHORT).show();
            }
            return;
        }
    }
}


private String getImeiNumber() {
    final TelephonyManager telephonyManager = (TelephonyManager) this.getSystemService(Context.TELEPHONY_SERVICE);

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        //getDeviceId() is Deprecated so for android O we can use getImei() method
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_PHONE_STATE) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return telephonyManager.getImei();
        }
        return telephonyManager.getImei();
    } else {
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_PHONE_STATE) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return telephonyManager.getImei();
        }
        return telephonyManager.getImei();
    }

}

}

我创建了另一个应用程序，其中包含一个用于接收 imei 的广播接收器。下面是application2的代码

    package com.example.activity_2;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;

import static android.content.Intent.EXTRA_TEXT;


public class MainActivity extends AppCompatActivity {


    TextView tv_imei;


    public class Receiver extends BroadcastReceiver {

        @Override
        public void onReceive(Context context, Intent intent) {

            StringBuilder imei= new StringBuilder();
            if (intent.getAction()==("com.example.activity_1")) {
                System.out.println("*****GOT THE INTENT********");
                StringBuilder append = imei.append("IMEI: " + intent.getExtras() + "\n");
                String log = imei.toString();
                Log.d("Received", log);
            }


        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        tv_imei = (TextView) findViewById(R.id.tv_imei);


        // Get intent, action and MIME type
        IntentFilter IMEI = new IntentFilter();
        IMEI.addAction("com.example.activity_1");
        IMEI.setPriority(100);
        BroadcastReceiver br = new Receiver();
        registerReceiver(br,IMEI);



    }
}

我不知道为什么第二个应用程序没有收到任何东西，因为我对 java 和一般编程一点也不熟悉。

提前谢谢你

Answer 1

简单来说，（详情请参考link）

隐式意图是动作的目标。因此，使用该操作声明的所有广播接收器都将被调用。鉴于，

显式意图是针对特定组件的意图。所以只有那个特定的组件会收到意图。在您的情况下，它是 Receiver，您需要对代码进行一些更改才能使其正常工作。

在清单文件中声明以下内容。

 <receiver android:name=".MainActivity$Receiver">
    <intent-filter>
        <action android:name="com.example.activity_1"></action>
    </intent-filter>
</receiver>

在您的点击监听器中发送广播时。 您还需要定义该特定组件 (Receiver) 以明确意图。否则，意图将是隐含的，并且鉴于您正在使用 API 28，它将无法正常工作。

// pass Receiver class parameter to your Intent object to make the intent explicit.
Intent sendImei = new Intent(view.getContext(), Receiver.class); // change is required here
sendImei.addFlags(sendImei.FLAG_INCLUDE_STOPPED_PACKAGES);
sendImei.setAction("com.example.activity_1");
sendImei.putExtra(Intent.EXTRA_TEXT, imei);
sendImei.setType("text/plain");
sendBroadcast(sendImei);