MKNetWorkKit使用

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。

self.yahooEngine = [[YahooEngine alloc] initWithHostName:@"download.finance.yahoo.com"];

 

YahooEngine的GET请求方法的申明

typedef void (^CurrencyResponseBlock)(double rate);

-(MKNetworkOperation*) currencyRateFor:(NSString*) sourceCurrency 

                   inCurrency:(NSString*) targetCurrency 

                 completionHandler:(CurrencyResponseBlock) completion

 

GET请求方法的实现

-(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

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(@"%@ %@ %@ %@", [error localizedDescription], [error localizedFailureReason], 

                                                                               [error localizedRecoveryOptions], [error localizedRecoverySuggestion]);

                                                                      }];

 

 

 

 

POST请求，上传一张图片

-(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。

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。

[self.yahooEngine useCache];

 

清空缓存使用如下方法

[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。

[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。

[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。

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。

 

[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。

[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。

-(MKNetworkOperation*) downloadFatAssFileFrom:(NSString*) remoteURL toFile:(NSString*) filePath {

   

  MKNetworkOperation *op = [self operationWithURLString:remoteURL];

   

  [op addDownloadStream:[NSOutputStream outputStreamToFileAtPath:filePath

                                                          append:YES]];

   

  [self enqueueOperation:op];

  return op;

}