IOS开垦根底知识--碎片48，ios底子知识--48

1：Assertion failure in dequeueReusableCellWithIdentifier:forIndexPath: 

static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier 
                                     forIndexPath:indexPath];

地点是在IOS9之下一向报闪退；后来改成上面化解：

static NSString *CellIdentifier = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

   if (cell==nil) {
      cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
    }

2:CoreTelephony框架不是私有库

个人框架的目录为：
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/System/Library/PrivateFrameworks/

能够看出CoreTelephony框架是在frameworks内并非PrivateFrameworks，所以它是足以放心使用的。英特网之所以有说CoreTelephony是私有库，是因为在iOS6的时候是个人框架，后来苹果又给公开了;

3:如何得到电话状态

a:首先要导入CoreTelephony框架：

@import CoreTelephony;

b:然后声雅培（Abbott卡塔尔个CTCallCenter变量：

@interface ViewController () {  
CTCallCenter *center_;   //为了避免形成retain cycle而声明的一个变量，指向接收通话中心对象
}  
@end

接下来监听电话状态：

- (void) aboutCall{   
    //获取电话接入信息
callCenter.callEventHandler = ^(CTCall *call){
    if ([call.callState isEqualToString:CTCallStateDisconnected]){
        NSLog(@"Call has been disconnected");

    }else if ([call.callState isEqualToString:CTCallStateConnected]){
        NSLog(@"Call has just been 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");
    }
};
}

还足以拿走运转商消息：

- (void)getCarrierInfo{
// 获取运营商信息
CTTelephonyNetworkInfo *info = [[CTTelephonyNetworkInfo alloc] init];
CTCarrier *carrier = info.subscriberCellularProvider;
NSLog(@"carrier:%@", [carrier description]);

// 如果运营商变化将更新运营商输出
info.subscriberCellularProviderDidUpdateNotifier = ^(CTCarrier *carrier) {
    NSLog(@"carrier:%@", [carrier description]);
};

// 输出手机的数据业务信息
NSLog(@"Radio Access Technology:%@", info.currentRadioAccessTechnology);
}

本来如此在真机实行测验，以下为出口新闻：

2015-12-29 16:34:14.525 RWBLEManagerDemo[1489:543655] carrier:CTCarrier (0x134e065c0) {
Carrier name: [中国移动]
Mobile Country Code: [460]
Mobile Network Code:[07]
ISO Country Code:[cn]
Allows VOIP? [YES]
}
2015-12-29 16:34:14.526 RWBLEManagerDemo[1489:543655] Radio Access Technology:CTRadioAccessTechnologyHSDPA

1：Assertion failure in dequeueReusableCellWithIdentifier:forIndexPath: static NSString *CellIdentifier = @" Cell " ;UITableV...