ios - AFNetworking NSData - 不兼容的 block 指针类型发送

Question

我正在尝试重做一些代码以使用 AFNetworking。我有下面这个方法:

-(NSArray *)GetTableDataOfPhase:(NSString *)phase
{
    NSString *phaseRequestString = [NSString stringWithFormat:@"%@?jobNo=%@",kIP,phase];
    NSURL *JSONURL = [NSURL URLWithString:phaseRequestString];
    NSURLResponse* response = nil;
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:JSONURL];
            NSData* data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:nil];
        if(data == nil)
            return nil;
        NSError *myError;
        NSArray *tableArray = [[NSArray alloc]initWithArray:[NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&myError]];



    return tableArray;
}

现在我正试图改变它，所以它仍然返回一个数组，我试过这样做:

-(NSArray *)GetTableDataOfPhase:(NSString *)phase
{
    NSString *phaseRequestString = [NSString stringWithFormat:@"%@?jobNo=%@",kIP,phase];
    NSURL *JSONURL = [NSURL URLWithString:phaseRequestString];
    NSURLResponse* response = nil;
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:JSONURL];

    AFHTTPRequestOperation *operation = [[[AFHTTPRequestOperation alloc] initWithRequest:request] autorelease];

    [operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {

        NSData* data = [NSURLConnection sendSynchronousRequest:responseObject returningResponse:&response error:nil];
        if(data == nil)
            return nil;
        NSError *myError;
        NSArray *tableArray = [[NSArray alloc]initWithArray:[NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&myError]];

    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {


    }];

    [operation start];


    return tableArray;
}

但是我得到了这个错误:

/Users/jamessuske/Documents/My Programs/SSiPad(Device Only)ios7/SchedulingiPadApplication/Classes/LHJSonData.m:168:46: Incompatible block pointer types sending 'void *(^)(AFHTTPRequestOperation *, id)' to parameter of type 'void (^)(AFHTTPRequestOperation *, id)'

和这个警告:

/Users/jamessuske/Documents/My Programs/SSiPad(Device Only)ios7/SchedulingiPadApplication/Classes/LHJSonData.m:170:97: Sending 'NSURLResponse *const *' to parameter of type 'NSURLResponse **' discards qualifiers

我是这样调用它的:

- (void)GetRequest
{
    //refresh table view
    [dataSource.editedCellHolder removeAllObjects];
    [dataSource.cellHolder removeAllObjects];
    [dataSource.cellHolderDisplay removeAllObjects];


    NSArray *tableData = [dataSource.areaData GetTableDataOfPhase:[NSString stringWithFormat:@"%@%@",areaPickerSelectionString,unitPickerSelectionString]];

    if(tableData == nil)
        [self CustomAlert:@"Data was not recieved from the server, please check internet/VPN settings, Or contact Software Vendor for assistance."];
    [dataSource PopulateTableData:tableData];
    [indicatorView stopAnimating];
    [indicatorView removeFromSuperview];
    [loadingView removeFromSuperview];
    loadingView = nil;
    indicatorView =nil;
    [NSTimer scheduledTimerWithTimeInterval:0.2f target:self selector:@selector(DisplayTable) userInfo:nil repeats:NO];

}

Answer 1

一些事情:

1. 使用 AFNetworking，您应该完全失去 NSURLConnection 请求。

2. 同样，默认的 responseSerializer 会为您进行 JSON 解析，因此您可能会丢失 NSJSONSerialization 解析。 AFNetworking 会为您完成这一切。

3. 同样，不要手动构建 URL 参数，而是再次让 AFNetworking 为您完成。默认情况下，AFNetworking 使用一个 requestSerializer 来为您构建请求。

4. 您的旧方法同步运行，这通常不是一个好主意。相反，您应该使用异步模式(例如 completionHandler block )。

所以，将所有这些放在一起，它可能看起来像:

- (void)getTableDataOfPhase:(NSString *)phase completionHandler:(void (^)(NSArray *resultsObject, NSError *error))completionHandler
{
    AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
    NSDictionary *parameters = @{@"jobNo" : phase};

    [manager GET:kIP parameters:parameters success:^(AFHTTPRequestOperation *operation, id responseObject) {
        completionHandler(responseObject, nil);
    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        completionHandler(nil, error);
    }];
}

你可以这样调用它:

[self getTableDataOfPhase:@"..." completionHandler:^(NSArray *resultsObject, NSError *error) {
    if (resultsObject) {
        // use NSArray here
    } else {
        NSLog(@"error = %@", error);
    }
}];

// but don't try to use the `resultsObject` array here!