iphone - map View 崩溃时的 GDirections 路线

Question

我正在使用 AFNetworking，并且正在学习有关通过从 google 路线获取路线在 iphone 屏幕上绘制路线的教程。我正在使用 JSON 和 AFNetworking。我从教程中复制了代码，您可以在这里找到:Tutorial

如果您还选择复制和测试此代码，请注意:您需要来自此 github 页面的 AFNetworking:AFNetworking Download

您还必须自己在 .h 中将变量 _path 定义为 NSMutableArray，否则您会收到错误，因为他们没有定义它但引用了它。

代码如下:

        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];

所以这是我的问题

感谢那些提供帮助的人。我已经测试了没有错误的代码，但现在在尝试制作路线时发现了这一点。它在这里崩溃:

- (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];

        }

    }

附错误说明:

-[__NSCFData objectForKey:]: unrecognized selector sent to instance 0x2004bb80

你们能帮忙吗？谢谢!

Answer 1

Let me also say that the AFHTTPClient previously did not have this HTTPOperationWithRequest class method as shown, but I had to copy and paste it in from AFHTTPRequestOperation.

我从您的 github 链接中克隆了 AFNetworking，并在 AFHTTPClient.h 文件中找到了它:

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

我想知道为什么您收到错误而不是“找不到方法”警告。 HTTPRequestOperationWithRequest 是实例方法，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，你链接的教程是正确的。