最近再做視頻播放的項(xiàng)目，有個(gè)需求就是監(jiān)聽系統(tǒng)來電，遇到一些小坑叫乌，找不到合適的資料，于是總結(jié)一下徽缚。

<p>代碼如下：

CoreTelephony/CTCallCenter框架定義了一個(gè)在app運(yùn)行時(shí)憨奸，監(jiān)聽來電的block，用來app處理在來電時(shí)的各種情況凿试。

在回調(diào)中排宰，定義了四周類型：
</p><pre><code>這是一個(gè)代碼區(qū)塊。
</code>p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 11.0px Menlo; min-height: 13.0px}p.p2 {margin: 0.0px 0.0px 0.0px 0.0px; font: 11.0px Menlo; color: #d12f1b}p.p3 {margin: 0.0px 0.0px 0.0px 0.0px; font: 11.0px Menlo; color: #78492a}p.p4 {margin: 0.0px 0.0px 0.0px 0.0px; font: 11.0px Menlo}span.s1 {font-variant-ligatures: no-common-ligatures}span.s2 {font-variant-ligatures: no-common-ligatures; color: #78492a}span.s3 {font-variant-ligatures: no-common-ligatures; color: #703daa}span.s4 {font-variant-ligatures: no-common-ligatures; color: #bb2ca2}span.s5 {font-variant-ligatures: no-common-ligatures; color: #000000}span.s6 {font-variant-ligatures: no-common-ligatures; color: #272ad8}

import <Foundation/Foundation.h>

import <CoreTelephony/CoreTelephonyDefines.h>

NS_ASSUME_NONNULL_BEGIN

CORETELEPHONY_EXTERN NSString * const CTCallStateDialing __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_4_0);
CORETELEPHONY_EXTERN NSString * const CTCallStateIncoming __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_4_0);
CORETELEPHONY_EXTERN NSString * const CTCallStateConnected __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_4_0);
CORETELEPHONY_EXTERN NSString * const CTCallStateDisconnected __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_4_0);

CORETELEPHONY_CLASS_AVAILABLE(4_0)</pre>

這個(gè)block红省，在來電時(shí)额各，會被調(diào)用多次，第一次觸發(fā)CTCallStateIncoming吧恃，當(dāng)無人接聽或者掛斷虾啦，會再次調(diào)用block，觸發(fā)CTCallStateDisconnected，有人接聽觸發(fā)CTCallStateConnected傲醉，所以蝇闭，這個(gè)block至少會觸發(fā)兩次，最多觸發(fā)四次硬毕。

注：CTCallCente必須用全局
</p><pre><code>
//
// ViewController.m
// cll
//
// Created by ChangQing Yang on 16/6/1.
// Copyright ? 2016年 ChangQing Yang. All rights reserved.
//

import "ViewController.h"

//導(dǎo)入系統(tǒng)的頭文件

import <CoreTelephony/CTCallCenter.h>

import <CoreTelephony/CTCall.h>

@interface ViewController ()

@property(nonatomic,strong)CTCallCenter *callCenter; //必須在這里聲明呻引，要不不會回調(diào)block

@end

@implementation ViewController

• (void)viewDidLoad {

  [super viewDidLoad];

  _callCenter = [[CTCallCenter alloc] init];

  _callCenter.callEventHandler=^(CTCall* call){

    if([call.callState isEqualToString:CTCallStateDisconnected])
        
    {
        NSLog(@"Call has been disconnected");
    }
    
    else if([call.callState isEqualToString:CTCallStateConnected])
        
    {
        NSLog(@"Callhasjustbeen connected");
    }
    
    else if([call.callState isEqualToString:CTCallStateIncoming])
        
    {
        NSLog(@"Call is incoming");
    }
    
    else if([call.callState isEqualToString:CTCallStateDialing])
        
    {
        NSLog(@"Call is Dialing");
    }
    
    else
    {
        NSLog(@"Nothing is done");
    }
  

  };

} </pre>

小結(jié)：
根據(jù)需求來做相應(yīng)block里面回調(diào)的處理，注意考慮在block里面操作的時(shí)候要定義__bolck吐咳。
如發(fā)現(xiàn)錯誤或不足逻悠，歡迎指正，如有需要韭脊，聯(lián)系qq 1392550437.
謝謝童谒。