如何使用sendAsynchronousRequest中的值？

Question

我使用Http POST請求和NSURLRequest解析一些JSON數據。但是當我得到sendAsynchronousRequest下的值時，我不能使用那些請求的外側。請參閱示例波紋管：

[NSURLConnection sendAsynchronousRequest:rq queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) 
    { 
     NSError *parseError = nil; 
     dictionary = [NSJSONSerialization JSONObjectWithData:data options:0 error:&parseError]; 
     NSLog(@"Server Response (we want to see a 200 return code) %@",response); 
     NSLog(@"dictionary %@",dictionary); 
    }]; 

我的查詢是如何使用字典值，我需要它？謝謝

Answer 1

你可以在很多方面做到這一點。一種方法是聲明一個屬性並在塊內使用它。

當你在進行異步呼叫時，最好有自己的自定義塊來響應這些呼叫。

首先聲明一個完成塊：

typedef void (^ ResponseBlock)(BOOL success, id response); 

，並宣佈使用該塊作爲PARAM方法：

- (void)processMyAsynRequestWithCompletion:(ResponseBlock)completion; 

，包括在這個方法您的異步調用：

- (void)processMyAsynRequestWithCompletion:(ResponseBlock)completion{ 

[NSURLConnection sendAsynchronousRequest:rq queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) 
{ 
    NSError *parseError = nil; 
    dictionary = [NSJSONSerialization JSONObjectWithData:data options:0 error:&parseError]; 
    NSLog(@"Server Response (we want to see a 200 return code) %@",response); 
    NSLog(@"dictionary %@",dictionary); 
    completion(YES,response); //Once the async call is finished, send the response through the completion block 
}]; 

} 

你可以在任何你想要的地方調用這個方法。

[classInWhichMethodDeclared processMyAsynRequestWithCompletion:^(BOOL success, id response) { 
     //you will receive the async call response here once it is finished. 
     NSDictionary *dic = (NSDictionary *)response; 
     //you can also use the property declared here 
      _dic = (NSDictionary *)response; //Here dic must be declared strong 
}];