ios-等待AFJSONRequestOperation完成

等待AFJSONRequestOperation完成

使用AFNetworking獲取網站的一些JSON信息，如何從asynchronou請求返回得到響應？

- (id) descargarEncuestasParaCliente:(NSString *)id_client{

        NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:[NSString stringWithFormat:@"http://whatever.com/api/&id_cliente=%@", id_client]]];

        __block id RESPONSE;

        AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) {

            RESPONSE = JSON;

        } failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON) {
            NSLog(@"ERROR: %@", error);
        }];

        [operation start];

        return RESPONSE;
    }

最佳回答：

因為是異步執行的關系，顯然你這樣返回肯定不能及時得到結果。
你可以將你的方法使用block改造一下

- (void) descargarEncuestasParaCliente:(NSString *)id_client block:(void(^)(id json))processResult{

        NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:[NSString stringWithFormat:@"http://whatever.com/api/&id_cliente=%@", id_client]]];    
        AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) {
            processResult(JSON);  ///回調處理返回的json結果
        } failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON) {
            NSLog(@"ERROR: %@", error);
        }];

        [operation start];
    }

調用：

[self descargarEncuestasParaCliente:@"1" block:^(id json) {
      NSLog(@"return result is :%@",json);
}