现在流行的第三方网络请求库有很多,ASIHTTPRequest、AFNetWorking等,每个人都自己的使用习惯,我推荐一个印度小伙子写的一个超轻量型框架MKNetWorkKit。 由于博客迁移至www.coderyi.com,文章请看http://www.coderyi.com/archives/422
由于博客迁移至www.coderyi.com,文章请看http://www.coderyi.com/archives/422
MKNetWorkKit是由一个印度小伙子写的,是用于网络请求的库,支持ARC,代码的网址这里给出。
作者源码地址(MugunthKumar):https://github.com/MugunthKumar/MKNetworkKit
作者关于类库介绍的地址(MugunthKumar):http://blog.mugunthkumar.com/products/ios-framework-introducing-mknetworkkit/
作者类库介绍中文翻译地址(翻译作者,csdn博主kmyhy,杨宏焱):http://blog.csdn.net/kmyhy/article/details/12276287
这里面大多数时候会引用到它里面的demo,MKNetWorkKit-iOS-Demo,本文主要是根据作者原文以及作者的demo还有自己的使用写的文章。
在整个程序中只有一个全局队列
MKNetWorkKit中主要有两个类,MKNetworkEngine和MKNetworkOperation,MKNetworkOperation就是一个操作,是NSOperation的子类,每个HTTP操作通过MKNetworkEngine入队,队列是一个NSOperationQueue,在程序是一个单例,在MKNetworkEngine的initialize里创建。
GET请求
一般自己会复写MKNetworkEngine,在这里提供一个每一个网络请求的接口,可以传入参数,请求完成和失败的block。
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self.yahooEngine = [[YahooEngine alloc] initWithHostName:@ "download.finance.yahoo.com" ]; |
YahooEngine的GET请求方法的申明
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typedef void (^CurrencyResponseBlock)( double rate); -(MKNetworkOperation*) currencyRateFor:(NSString*) sourceCurrency inCurrency:(NSString*) targetCurrency completionHandler:(CurrencyResponseBlock) completion |
GET请求方法的实现
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-(MKNetworkOperation*) currencyRateFor:(NSString*) sourceCurrency inCurrency:(NSString*) targetCurrency completionHandler:(CurrencyResponseBlock) completionBlock errorHandler:(MKNKErrorBlock) errorBlock { MKNetworkOperation *op = [self operationWithPath:YAHOO_URL(sourceCurrency, targetCurrency) params:nil httpMethod:@ "GET" ]; [op addCompletionHandler:^(MKNetworkOperation *completedOperation) { // the completionBlock will be called twice. // if you are interested only in new values, move that code within the else block NSString *valueString = [[completedOperation responseString] componentsSeparatedByString:@ "," ][1]; DLog(@ "%@" , valueString); if ([completedOperation isCachedResponse]) { DLog(@ "Data from cache %@" , [completedOperation responseString]); } else { DLog(@ "Data from server %@" , [completedOperation responseString]); } completionBlock([valueString doubleValue]); }errorHandler:^(MKNetworkOperation *errorOp, NSError* error) { errorBlock(error); }]; [self enqueueOperation:op]; return op; } |
GET请求方法的调用
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self.currencyOperation = [ApplicationDelegate.yahooEngine currencyRateFor:@ "SGD" inCurrency:@ "USD" completionHandler:^( double rate) { [[[UIAlertView alloc] initWithTitle:@ "Today's Singapore Dollar Rates" message:[NSString stringWithFormat:@ "%.2f" , rate] delegate:nil cancelButtonTitle:NSLocalizedString(@ "Dismiss" , @ "" ) otherButtonTitles:nil] show]; } errorHandler:^(NSError* error) { DLog(@ "%@\t%@\t%@\t%@" , [error localizedDescription], [error localizedFailureReason], [error localizedRecoveryOptions], [error localizedRecoverySuggestion]); }]; |
POST请求,上传一张图片
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-(MKNetworkOperation*) uploadImageFromFile:(NSString*) file completionHandler:(IDBlock) completionBlock errorHandler:(MKNKErrorBlock) errorBlock { MKNetworkOperation *op = [self operationWithPath:@ "upload.php" params:@{@ "Submit" : @ "YES" } httpMethod:@ "POST" ]; [op addFile:file forKey:@ "image" ]; // setFreezable uploads your images after connection is restored! [op setFreezable:YES]; [op addCompletionHandler:^(MKNetworkOperation* completedOperation) { NSString *xmlString = [completedOperation responseString]; DLog(@ "%@" , xmlString); completionBlock(xmlString); } errorHandler:^(MKNetworkOperation *errorOp, NSError* error) { errorBlock(error); }]; [self enqueueOperation:op]; return op; } |
上传的时候可以增加一个进度条,所以在调用这个方法的时候可以有以下代码。
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NSString *uploadPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingFormat:@ "/SampleImage.jpg" ]; self.uploadOperation = [ApplicationDelegate.testsEngine uploadImageFromFile:uploadPath completionHandler:^(id twitPicURL) { UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@ "Uploaded to" message:(NSString*) twitPicURL delegate:nil cancelButtonTitle:NSLocalizedString(@ "Dismiss" , @ "" ) otherButtonTitles:nil]; [alert show]; self.uploadProgessBar.progress = 0.0; } errorHandler:^(NSError* error) { [UIAlertView showWithError:error]; }]; [self.uploadOperation onUploadProgressChanged:^( double progress) { DLog(@ "%.2f" , progress*100.0); self.uploadProgessBar.progress = progress; }]; |
正确显示网络状态指示
正确显示网络状态指示的判断条件就是操作operation数大于0的时候。
自动改变队列大小
在wifi以及3G网络是会调用setMaxConcurrentOperationCount:方法切换最大操作数的大小。
自动缓存
MKNetWorkKit能够缓存你所有的GET请求,当请求相同时会调用本地缓存内容。
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[self.yahooEngine useCache]; |
清空缓存使用如下方法
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[ApplicationDelegate.yahooEngine emptyCache]; |
冻结网络操作
网络断开时的网络请求会被冻结,通过NSKeyedArchiver序列化在本地,当有网时会再次请求。MKNetworkOperation的setFreezable:方法就是冻结操作。
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[op setFreezable:YES]; |
类似的请求只请求一个操作
就是同一个URL只请求一次。
图片缓存
MKNetworkEngine的imageAtURL:completionHandler:errorHandler:方法能够缓存图片。
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[ApplicationDelegate.apiEngine imageAtURL:[NSURL URLWithString:(_strategyModel.titlepic)] completionHandler:^(UIImage* fetchedImage, NSURL* url, BOOL isInCache){ [iv setImage:fetchedImage]; }errorHandler:nil]; |
当然MKNetworkEngine的operationWithURLString: params: httpMethod:方法也可以请求图片,并且缓存,它其实就是根据一个URL地址来创建一个网络线程,然后把它加入到队列就可以了。
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MKNetworkOperation *op1 =[ApplicationDelegate.apiEngine operationWithURLString:_strategyModel.titlepic params:nil httpMethod:nil]; [op1 addCompletionHandler:^(MKNetworkOperation *completedOperation) { // [op1 responseImage]; [iv setImage:[completedOperation responseImage]]; } errorHandler:^(MKNetworkOperation *errorOp, NSError* error) { }]; [ApplicationDelegate.apiEngine enqueueOperation:op1]; |
其实MKNetworkOperation有各种response数据,这里是responseImage,还有responseString、responseJSON、responseXML。
不过请求一个图片还可以使用MK提供的category,UIImageView+MKNetworkKitAdditions里面的方法,如下,不过我试了之后好像没有缓存,不过这个可以用于tableview上每个cell上显示的图片,比上面的要方便许多。
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[self.thumbnailImage setImageFromURL:[NSURL URLWithString:self.loadingImageURLString] placeHolderImage:nil]; |
缓存operation
其实每一个get请求都有缓存,要想知道你返回的数据是否缓存,可以用以下方法。
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[op addCompletionHandler:^(MKNetworkOperation *completedOperation) { // the completionBlock will be called twice. // if you are interested only in new values, move that code within the else block if ([completedOperation isCachedResponse]) { DLog(@ "Data from cache %@" , [completedOperation responseString]); } else { DLog(@ "Data from server %@" , [completedOperation responseString]); } completionBlock([valueString doubleValue]); }errorHandler:^(MKNetworkOperation *errorOp, NSError* error) { errorBlock(error); }]; |
下载文件
下载文件的时候也可以增加进度条,方法类似上面上传文件的使用,下载文件痛哟在操作上增加一个一个输出流,下载文件的实现可以如下。
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-(MKNetworkOperation*) downloadFatAssFileFrom:(NSString*) remoteURL toFile:(NSString*) filePath { MKNetworkOperation *op = [self operationWithURLString:remoteURL]; [op addDownloadStream:[NSOutputStream outputStreamToFileAtPath:filePath append:YES]]; [self enqueueOperation:op]; return op; } |