Question

如何返回完成块中填充的数组？将一些JSON解析为一个对象数组。

-(NSArray *)GetMapVehiclePoints
{
    NSString *methodURL = [NSString stringWithFormat:@"%@GetMapVehiclePoints", BASE_URL];
   __block NSArray *parsedVehicles = [[NSArray alloc]init];

    AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
    [manager GET:methodURL parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) {

        NSArray *vehicles = (NSArray *)responseObject;
        parsedVehicles = [self parseVehicles:vehicles];

    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        NSLog(@"Error: %@", error);
    }];

    return parsedVehicles;
}

每次我返回这个方法时，我得到一个空数组，因为完成块还没有运行。如何在块内返回数组？

Answer 1

getMapVehiclePoints无法/不应该返回一个数组。请改用回调块......

typedef void(^CallbackBlock)(id value);

- (void)getMapVehiclePointsWithCallback:(CallbackBlock)callback {
    NSString *methodURL = [NSString stringWithFormat:@"%@GetMapVehiclePoints", BASE_URL];
    AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
    [manager GET:methodURL parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) {
        if (callback) callback([self parseVehicles:(id)responseObject]);
    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        NSLog(@"Error: %@", error);
        if (callback) callback(@[]);
    }];
}

[self getMapVehiclePointsWithCallback:^(NSArray *vehiclePoints) {
    NSLog(@"%@", vehiclePoints);
}];

Answer 2

我传递的是方法的完成块

- (void)GetMapVehiclePointsWithCompletion:(void (^)(NSArray *points))completion;

在块中返回NSArray

2 个答案: