ios函數 二、三次封裝和block作用__函數

ios函數 二、三次封裝和block作用

ios 中對常使用的模組或者公用模組做二次，三次封裝，對已知api做二次封裝，以更便於自己在項目中使用。

以下為例子：

+ (NSURLSessionDataTask *)requestDictionary:(void (^)(NSDictionary *, NSError *))block
                                    withURL:(NSString *)url
                                  parameter:(NSDictionary *)parameter
{
    //NSLog(@"url====%@",url);
    
    return [[SCAppAPIClient sessionManager] GET:url
                                     parameters:parameter
                                        success:^(NSURLSessionDataTask *task, id responseObject) {
                                            NSString *successString = [[NSJSONSerialization JSONObjectWithData:responseObject
                                                                                                       options:kNilOptions
                                                                                                         error:NULL] objectForKey:@"Value"];
                                            NSDictionary *resultDict;
                                            if ([successString isEqualToString:@"success"]) {
                                                resultDict = [[[NSJSONSerialization JSONObjectWithData:responseObject
                                                                                                             options:kNilOptions
                                                                                                               error:NULL] valueForKeyPath:@"SuccessInfo"] objectAtIndex:0];
                                            }
                                            if ([successString isEqualToString:@"failed"]) {
                                                resultDict = [NSJSONSerialization JSONObjectWithData:responseObject
                                                                                               options:kNilOptions
                                                                                                 error:NULL];
                                            }
                                            if (block) {
                                                block([NSDictionary dictionaryWithDictionary:resultDict], nil);
                                            }
                                        } failure:^(NSURLSessionDataTask *task, NSError *error) {
                                            if (block) {
                                                block([NSDictionary dictionary], error);
                                            }
                                        }];
}

SCAppAPIClient sessionManager

擷取到的是一個單利傳回值，GET 後面一個方法為 api內建方法；

單利為

#import "SCAppAPIClient.h"
#import "Macros.h"


@implementation SCAppAPIClient

+ (instancetype)sessionManager
{
    static SCAppAPIClient *_sessionManager = nil;
    static dispatch_once_t onceToken;
    
    dispatch_once(&onceToken, ^{
        _sessionManager = [[self alloc] initWithBaseURL:[NSURL URLWithString:OFFICIAL_URL]];
        _sessionManager.requestSerializer = [AFJSONRequestSerializer serializer];
        _sessionManager.responseSerializer = [AFHTTPResponseSerializer serializer];
    });
    
    return _sessionManager;
}
@end