android 通话过程中发送数字指令DTMF

场景：

接管系统的拨号盘及电话应用，需要拨打如中国移动等运营商时能发送数字按键指令。（mtk的手机方案）

参考文档：

发送dtmf键盘事件(模拟通话界面键盘事件)

需要权限：

系统权限及系统签名
在AndroidManifest.xml里增加

android:sharedUserId="android.uid.phone" 或 android:sharedUserId="android.uid.system"

遇到的问题：

由于我们定制了拨号界面，里面有很多交互逻辑以及第三方依赖，不可能将这个页面单独设置为android:process="com.android.phone"进程，但发送dtmf又必须在这个进程中。

解决方案：

单独将发送dtmf的功能独立到com.android.phone进程的service中

package ***.service;

import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.IBinder;
import android.util.Log;
import java.lang.reflect.Method;

public class DtmfSendService extends Service {

private String ACTION_SEND_DTMF = "net.bonvo.client.bonvobox.send_dtmf";
private String TAG = "DtmfSendService";
private SendDtmfReceiver mReceiver;
@Override
public void onCreate() {
    super.onCreate();
    registerReceiver();
}

@Override
public IBinder onBind(Intent intent) {
    return null;
}

@Override
public void onDestroy() {
    super.onDestroy();
    if (mReceiver != null) {
        unregisterReceiver(mReceiver);
    }
}

private void registerReceiver() {
    mReceiver = new SendDtmfReceiver();
    IntentFilter filter = new IntentFilter();
    filter.addAction(ACTION_SEND_DTMF);
    registerReceiver(mReceiver, filter);
}

public void sendDtmf(char keycode) {
    //https://blog.csdn.net/jinliang_890905/article/details/43458877
    //https://www.cnblogs.com/IT-Goddess/p/5725705.html
    //https://stackoverflow.com/questions/4745899/how-to-access-com-android-internal-telephony-callmanager
    //源码：http://androidxref.com/9.0.0_r3/xref/frameworks/opt/telephony/src/java/com/android/internal/telephony/CallManager.java#1216
    try {
        ClassLoader classLoader = ClassLoader.getSystemClassLoader();
        final Class<?> classCallManager = classLoader.loadClass("com.android.internal.telephony.CallManager");
        Log.i(TAG, "Class loaded " + classCallManager.toString());

        Method methodGetInstance = classCallManager.getDeclaredMethod("getInstance");
        Log.i(TAG, "Method loaded " + methodGetInstance.getName());

        Object objectCallManager = methodGetInstance.invoke(null);
        Log.i(TAG, "Object loaded " + objectCallManager.getClass().getName());

        Method methodSendDtmf = classCallManager.getDeclaredMethod("sendDtmf", char.class);
        methodSendDtmf.setAccessible(true);
        Log.i(TAG, "Method loaded " + methodSendDtmf.getName());

        Log.i(TAG, "SendDtmf = " + methodSendDtmf.invoke(objectCallManager, keycode));

    } catch (Exception e) {
        e.printStackTrace();
    }
}

class SendDtmfReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent.getAction() != null && intent.getAction().contentEquals(ACTION_SEND_DTMF)) {
            char code = intent.getCharExtra("dtmfCode",'-');
            if (code != '-') {
                Log.e(TAG,"发送dtmf=" + code);
                sendDtmf(code);
            }
        }
    }
}
}

清单文件中申明service

<service android:name="***.service.DtmfSendService"
        android:process="com.android.phone" />

使用方法：

1、在通话界面先启动startService
2、需要发送指令时发送
    Intent dtmfIntent = new Intent();
    dtmfIntent.setAction(CustomAction.SEND_DTMF);
    dtmfIntent.putExtra("dtmfCode",key);
    sendBroadcast(dtmfIntent);