Question

我正在使用AFNetworking，我正在通过从谷歌指示获取路线来关注在iphone屏幕上绘制路线的教程。我使用的是JSON和AFNetworking。我从您可以在此处找到的教程中复制了代码：Tutorial

如果您还选择复制并测试此代码，请注意：您需要此github页面中的AFNetworking：AFNetworking Download

你还必须自己在.h中将变量_path定义为NSMutableArray，否则你会得到错误，因为它们没有定义但引用它。

以下是代码：

        AFHTTPClient *_httpClient = [AFHTTPClient clientWithBaseURL:[NSURL URLWithString:@"http://maps.googleapis.com/"]];

    [_httpClient registerHTTPOperationClass: [AFJSONRequestOperation class]];

    NSMutableDictionary *parameters = [[NSMutableDictionary alloc] init];

    [parameters setObject:[NSString stringWithFormat:@"%f,%f", location.coordinate.latitude, location.coordinate.longitude] forKey:@"origin"];

    [parameters setObject:[NSString stringWithFormat:@"%f,%f", location2.coordinate.latitude, location2.coordinate.longitude] forKey:@"destination"];

    [parameters setObject:@"true" forKey:@"sensor"];

    NSMutableURLRequest *request = [_httpClient requestWithMethod:@"GET" path: @"maps/api/directions/json" parameters:parameters];

    request.cachePolicy = NSURLRequestReloadIgnoringLocalCacheData;

    AFHTTPRequestOperation *operation = [AFHTTPClient HTTPRequestOperationWithRequest:request success:^(AFHTTPRequestOperation *operation, id response) { 
        NSInteger statusCode = operation.response.statusCode;
        if (statusCode == 200) {
            [self parseResponse:response];

        } else {

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

    [_httpClient enqueueHTTPRequestOperation:operation];

所以继承我的问题

感谢那些帮助过的人。我已经测试了没有错误的代码，但现在发现在尝试制作路线时。它在这里崩溃了：

- (void)parseResponse:(NSDictionary *)response {

    NSArray *routes = [response objectForKey:@"routes"]; // CRASH HERE

    NSDictionary *routePath = [routes lastObject];

    if (routePath) {

        NSString *overviewPolyline = [[routePath objectForKey: @"overview_polyline"] objectForKey:@"points"];

        _path = [self decodePolyLine:overviewPolyline];

        NSInteger numberOfSteps = _path.count;

        CLLocationCoordinate2D coordinates[numberOfSteps];
        for (NSInteger index = 0; index < numberOfSteps; index++) {
            CLLocation *location = [_path objectAtIndex:index];
            CLLocationCoordinate2D coordinate = location.coordinate;

            coordinates[index] = coordinate;
        }

        MKPolyline *polyLine = [MKPolyline polylineWithCoordinates:coordinates count:numberOfSteps];
        [self.mapView addOverlay:polyLine];

        }

    }

使用错误说明：

- [__ NSCFData objectForKey：]：无法识别的选择器发送到实例0x2004bb80

你能帮忙吗？谢谢！

Answer 1

我还要说AFHTTPClient之前没有这个 HTTPOperationWithRequest类方法如图所示，但我不得不复制和从AFHTTPRequestOperation粘贴它。

我从您的github链接克隆了AFNetworking并在AFHTTPClient.h文件中找到了这个：

- (AFHTTPRequestOperation *)HTTPRequestOperationWithRequest:(NSURLRequest *)request 
                                                    success:(void (^)(AFHTTPRequestOperation *operation, id responseObject))success
                                                    failure:(void (^)(AFHTTPRequestOperation *operation, NSError *error))failure;

我想知道你为什么会收到错误而不是“找不到方法”警告。 HTTPRequestOperationWithRequest是实例方法，而不是类方法：

AFHTTPRequestOperation *operation = [_httpClient HTTPRequestOperationWithRequest:request success:^(AFHTTPRequestOperation *operation, id responseObject) {
        // do something
        ;
    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        ;
    }];

顺便说一句，您链接的教程是正确的。

Answer 2

好好玩了一下后我才明白了。如果包含route，则NSDictionary只会是JSONKit。这里与AFNetworking和JSONKit有一些关系。所以，我之前已经有了JSONKit个文件，因为我知道这个。但是AFHTTPClient并没有接受它，所以我不得不说出这句话：

        [_httpClient setDefaultHeader:@"Accept" value:@"application/json"];

GDirections路线在地图上查看崩溃

2 个答案: