网络与实践中收集的一些可能有用的代码

1. 遍历NavigationController栈中的视图

XXView *rootViewController = nil;
for (UIViewController *VC in self.navigationController.viewControllers) {
     if ([VC isKindOfClass:[XXView class]]) {
         rootViewController = (XXView *)VC; 
    }
 }
 [self.navigationController popToViewController:rootViewController animated:YES];

 2. 背景音乐播放，支持mp3格式
需要先导入框架及代码中#import <AVFoundation/AVFoundation.h>

NSString *musicPath = [[NSBundle mainBundle] pathForResource:@"backgrounmusic" ofType:@"mp3"];
NSURL *url = [[NSURL alloc] initFileURLWithPath:musicPath];

AVAudioPlayer *player = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:nil];
// 创建播放器
self.myBackMusic = player; //赋值给自己定义的类变量
[url release];
[player release];

[myBackMusic prepareToPlay];
[myBackMusic setVolume:1];
myBackMusic.numberOfLoops = -1; //设置音乐播放次数  -1为一直循环
if(mainMusicStatus)
{
    [myBackMusic play]; //播放
}

3. 按钮播放声音、播放短声音

需要导入框架#import <AudioToolbox/AudioToolbox.h>

NSString *thesoundFilePath = [[NSBundle mainBundle] pathForResource:@"Clap Crowd" ofType:@"caf"]; //音乐文件路径
CFURLRef thesoundURL = (CFURLRef)[NSURL fileURLWithPath:thesoundFilePath];
AudioServesCreateSystemSoundID(thesoundURL, &sameViewSoundID);
//变量SoundID与URL对应

AudioServicesPlaySystemSound(sameViewSoundID); //播放SoundID声音

4. 判断网络是否连接

/***
* 此函数用来判断是否网络连接服务器正常
* 需要导入Reachability类
*/

+ (BOOL)isExistenceNetwork
{
    BOOL isExistenceNetwork;
    Reachability *reachability = [Reachability reachabilityWithHostName:@""];  // 测试服务器状态
    
     switch([reachability currentReachabilityStatus]) {
            case NotReachable:
                  isExistenceNetwork = FALSE;
                  break;
             case ReachableViaWWAN:
                   isExistenceNetwork = TRUE;
                   break;
              case ReachableViaWiFi:
                    isExistenceNetwork = TRUE;
                    break;
     }
     return  isExistenceNetwork;
}

5. 实时通知网络状况

/*
* 在应用委托的方法didFinishLaunchingWithOptions中添加
*/

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name:kReachabilityChangedNotification object:nil];
reachability = [[Reachability reachabilityWithHostName:@"www.baidu.com"] retain];
[reachability startNotifier];
........
return YES;

/**
*此函数通过判断联网方式，通知给用户
*/
- (void)reachabilityChanged:(NSNotification *)notification
{
      Reachability *curReachability = [notification object];
      NSParameterAssert([curReachability isKindOfClass:[Reachability class]]);
      NetworkStatus curStatus = [curReachability currentReachabilityStatus];
      if(curStatus == NotReachable) {
          [DOIN_Util logFax:@"连接失败"];
      }
}

6. 延时函数和Timer的使用

//延时函数：
[NSThread sleepForTimeInterval:5.0]； //暂停5s.


//Timer的使用：
NSTimer *connectionTimer;  //timer对象

//实例化timer
self.connectionTimer=[NSTimerscheduledTimerWithTimeInterval:1.5 target:selfselector:@selector(timerFired:) userInfo:nil repeats:NO];
[[NSRunLoop currentRunLoop]addTimer:self.connectionTimer forMode:NSDefaultRunLoopMode];
//用timer作为延时的一种方法   
do{
[[NSRunLoopcurrentRunLoop]runUntilDate:[NSDatedateWithTimeIntervalSinceNow:1.0]];
}while(!done); 

//timer调用函数
-(void)timerFired:(NSTimer *)timer{
done =YES;
}