如何禁用MKNetworkKit或MKNetworkEngine中的緩存？

Question

我正在嘗試使用MKNetworkEngine，但標題討論緩存。這對我的應用程序來說是非常糟糕的，因爲它需要下載貨幣兌換率JSON文件，而緩存是不可行的。

有沒有辦法爲整個MKNetworkEngine實例關閉緩存？

Answer 1

首先要做的事情是：你真的肯定你的緩存用例嗎？大多數提供Web服務的股票將其Cache-Pragma/ETags標頭設置爲合理的值。如果他們這樣做，MKNetworkKit將做正確的事情，並且只會響應您的代碼緩存命中，如果這對您的請求有效。

但是，您可以通過兩種方法控制緩存的使用情況。右從MKNetworkEngine.h：

/*! 
* @abstract Enqueues your operation into the shared queue. 
* 
* @discussion 
* The operation you created is enqueued to the shared queue. 
* When forceReload is NO, this method behaves like enqueueOperation: 
* When forceReload is YES, No cached data will be returned even if cached data is available. 
* @seealso 
* enqueueOperation: 
*/ 
-(void) enqueueOperation:(MKNetworkOperation*) operation forceReload:(BOOL) forceReload; 

調用enqeueOperation:forceReload:與forceReload設置爲YES會做的伎倆。像這樣：

-(MKNetworkOperation *)myNetworkOperation onCompletion:(MYComplectionBlock)completionBlock onError:(MKNKErrorBlock)errorBlock { 

    MKNetworkOperation *op = [self operationWithPath:kURLPath params:nil httpMethod:@"GET" ssl:NO]; 
    [op onCompletion:^(MKNetworkOperation *completedOperation) { 
     // handle the response 
     completionBlock(...) 
    } onError:^(NSError *error) { 
     errorBlock(error); 
    }]; 

    [self enqueueOperation:op forceReload:YES]; 
    return op; 
} 

進一步可以明確地清空緩存（注意，這意味着排空所有請求緩存）一起[self emptyCache]只是[self enqueueOperation:op]之前你MKNetworkEngine子類的內部通話。

-(MKNetworkOperation *)myNetworkOperation onCompletion:(MYComplectionBlock)completionBlock onError:(MKNKErrorBlock)errorBlock { 

    MKNetworkOperation *op = [self operationWithPath:kURLPath params:nil httpMethod:@"GET" ssl:NO]; 
    [op onCompletion:^(MKNetworkOperation *completedOperation) { 
     // handle the response 
     completionBlock(...) 
    } onError:^(NSError *error) { 
     errorBlock(error); 
    }]; 

    [self emptyCache]; 
    [self enqueueOperation:op]; 
    return op; 
}