在你要監(jiān)聽(tīng)來(lái)電的地方就行

 private void telephony() {
        //獲得相應(yīng)的系統(tǒng)服務(wù)
        TelephonyManager tm = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
       
        if(tm != null) {
            try {
                MyPhoneCallListener myPhoneCallListener = new MyPhoneCallListener();
                myPhoneCallListener.setCallListener(new MyPhoneCallListener.CallListener() {
                    @Override
                    public void onCallRinging() {
                        //回調(diào)，做你想做的，我是關(guān)閉當(dāng)前界面
                        finish();
                    }
                });
                // 注冊(cè)來(lái)電監(jiān)聽(tīng)
                tm.listen(myPhoneCallListener, PhoneStateListener.LISTEN_CALL_STATE);
            } catch(Exception e) {
                // 異常捕捉
            }
        }
    }

PhoneStateListener的onCallStateChanged方法監(jiān)聽(tīng)來(lái)電狀態(tài)
監(jiān)聽(tīng)電話(huà)的類(lèi) MyPhoneCallListener.java

package com.hyphenate.chatuidemo.receiver;

import android.telephony.PhoneStateListener;
import android.telephony.TelephonyManager;
import android.util.Log;


/**
 * Created by Mr.Robot on 2018/1/23.
 * https://github.com/Siomt
 */

public class MyPhoneCallListener extends PhoneStateListener {

    private static final String TAG = "MyPhoneCallListener";
    protected CallListener listener;
         /**
         * 返回電話(huà)狀態(tài)
         *
         * CALL_STATE_IDLE 無(wú)任何狀態(tài)時(shí)
         * CALL_STATE_OFFHOOK 接起電話(huà)時(shí)
         * CALL_STATE_RINGING 電話(huà)進(jìn)來(lái)時(shí)
         */
    @Override
    public void onCallStateChanged(int state, String incomingNumber) {
        switch (state) {
            case TelephonyManager.CALL_STATE_IDLE:// 電話(huà)掛斷
                Log.d(TAG ,"電話(huà)掛斷...");
                break;
            case TelephonyManager.CALL_STATE_OFFHOOK: //電話(huà)通話(huà)的狀態(tài)
                Log.d(TAG ,"正在通話(huà)...");
                listener.onCallRinging();
                break;
            case TelephonyManager.CALL_STATE_RINGING: //電話(huà)響鈴的狀態(tài)
                Log.d(TAG ,"電話(huà)響鈴");
                break;
        }
        super.onCallStateChanged(state, incomingNumber);
    }
    //寫(xiě)個(gè)回調(diào)
    public void setCallListener(CallListener callListener){
        this.listener = callListener;
    }
    //回調(diào)接口
    public interface CallListener{
        void onCallRinging();
    }
}