子类化的 MKTileOverlay 不在地图上显示

Posted 2023-03-08

【中文标题】子类化的 MKTileOverlay 不在地图上显示

【英文标题】：Subclassed MKTileOverlay not displaying on map

【发布时间】：2014-11-05 17:11:52

【问题描述】：

我正在尝试从我们的 WMS 服务器显示 WMS 磁贴。我用旧的MKOverlay 实现了这一点，但我现在正在尝试将其更新为使用MKTileOverlay，但我无法显示瓷砖。这是我的课：

@interface WMSTileOverlay ()

@property (strong, nonatomic) NSString *API, *mapContext, *IDToken;

@end

@implementation WMSTileOverlay

-(instancetype)initWithAPI:(NSString *)API IDToken:(NSString *)IDToken andMapContext:(NSString *)mapContext 
    self = [super init];

    if (self) 
        self.API = API;
        self.mapContext = mapContext;
        self.IDToken = IDToken;
    

    return self;


-(NSURL *)URLForTilePath:(MKTileOverlayPath)path 
    DLog(@"fired");

    DLog(@"path | x:%ld y: %ld z: %ld scale: %f", (long)path.x, (long)path.y, (long)path.z, path.contentScaleFactor);

    NSString *resolvedURL = [self createWMSURLStringForTileX:path.x tileY:path.y zoomLevel:path.z];
    DLog(@"resolvedURL: %@", resolvedURL);
    return  [NSURL URLWithString:resolvedURL];


-(NSString *)createWMSURLStringForTileX:(NSInteger)tileX tileY:(NSInteger)tileY zoomLevel:(NSInteger)zoomLevel 
    NSString *WMSservice = @"wms";
    NSString *WMSversion = @"1.1.1";
    NSString *WMSrequest = @"GetMap";
    NSString *WMSMode = @"tiled";
    NSString *WMSTile = [NSString stringWithFormat:@"%d+%d+%d", tileX, tileY, zoomLevel];
    NSString *WMSFormat = @"image/png";
    NSString *WMSTransparancy = @"true";
    NSString *WMs-s-rS = @"EPSG:4326";
    NSString *WMSLayer = @"displayimg";

    DLog(@"%@", [NSString stringWithFormat:@"%@?map=%@&idtoken=%@&service=%@&version=%@&request=%@&SRS=%@&layers=%@&mode=%@&tile=%@&format=%@&transparent=%@", self.API, self.mapContext, self.IDToken, WMSservice, WMSversion, WMSrequest, WMs-s-rS, WMSLayer, WMSMode, WMSTile, WMSFormat, WMSTransparancy]);

    return [NSString stringWithFormat:@"%@?map=%@&idtoken=%@&service=%@&version=%@&request=%@&SRS=%@&layers=%@&mode=%@&tile=%@&format=%@&transparent=%@", self.API, self.mapContext, self.IDToken, WMSservice, WMSversion, WMSrequest, WMs-s-rS, WMSLayer, WMSMode, WMSTile, WMSFormat, WMSTransparancy];



-(void)loadTileAtPath:(MKTileOverlayPath)path result:(void (^)(NSData *, NSError *))result 
    DLog(@"fired");

    NSURLRequest *request = [NSURLRequest requestWithURL:[self URLForTilePath:path]];
    [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) 
        if (connectionError) 
            result (nil, connectionError);
        
        else 
            result (data, nil);
        
    ];


@end

我正在生成磁贴请求的 URL：

DEBUG | -[WMSTileOverlay URLForTilePath:] | path | x:60597 y: 92299 z: 18 scale: 1.000000
DEBUG | -[WMSTileOverlay createWMSURLStringForTileX:tileY:zoomLevel:] | https://WMS_SERVER?map=yupv9bvejd15fbmc0i1k62bvmdsbcafn.map&idtoken=852a468e65e5ed4023e7b704ea8c768f53c2df13da44e2f0c68fb5a559a130c8&service=wms&version=1.1.1&request=GetMap&SRS=EPSG:4326&layers=displayimg&mode=tiled&tile=60597+92299+18&format=image/png&transparent=true

我正在取回数据（它与我使用有效的旧 MKOverlay 类进行的 URL 调用相同）并且该类正在传回数据。但是没有绘制瓷砖。我这样创建类：

WMSTileOverlay *wmsTileOverlay = [[WMSTileOverlay alloc] initWithAPI:functionCall.API IDToken:functionCall.IDToken andMapContext:[self.mapper fetchMapContextForState:self.activeBoundarier.state]];
wmsTileOverlay.canReplaceMapContent = FALSE;

[self.mapView insertOverlay:wmsTileOverlay atIndex:0];

并实现了方法mapView:rendererForOverlay::

-(MKOverlayRenderer *)mapView:(MKMapView *)mapView rendererForOverlay:(id<MKOverlay>)overlay 
    DLog(@"fired");

    if ([overlay isKindOfClass:[MKTileOverlay class]]) 
        MKTileOverlay *tileOverlay = (MKTileOverlay *)overlay;

        if ([tileOverlay isKindOfClass:[WMSTileOverlay class]]) 
            WMSTileOverlay *wmsTileOverlay = (WMSTileOverlay *)tileOverlay;
            DLog(@"wmsTileOverlay.URLTemplate: %@", wmsTileOverlay.URLTemplate);

            MKTileOverlayRenderer *renderer = [[MKTileOverlayRenderer alloc] initWithTileOverlay:tileOverlay];

            return renderer;
        
    

    return nil;

我做错了什么？

【参考方案1】：

您是否设置了您的MKMapView 委托并被mapView:rendererForOverlay: 调用？

我和你做的事情几乎一样，而且对我来说效果很好。

#pragma mark - UIViewController

- (void)viewDidLoad

    [super viewDidLoad];

    WMSTileOverlay *overlay = [WMSTileOverlay new];
    overlay.canReplaceMapContent = YES;

    [self.mapView addOverlay:overlay level:MKOverlayLevelAboveLabels];


#pragma mark - MKMapViewDelegate

- (MKOverlayRenderer *)mapView:(MKMapView *)mapView rendererForOverlay:(id <MKOverlay>)overlay

    if ([overlay isKindOfClass:[WMSTileOverlay class]]) 
        return [[MKTileOverlayRenderer alloc] initWithTileOverlay:overlay];
    

    return nil;

还有，

- (NSURL *)URLForTilePath:(MKTileOverlayPath)path

    double left, bottom, right, top;

    // Conversion to bbox mechanism
    // ...

    NSString *urlString = [NSString stringWithFormat:@"%@&bbox=%f,%f,%f,%f", kWMSServerURL, left, bottom, right, top];

    return [NSURL URLWithString:[urlString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];


- (void)loadTileAtPath:(MKTileOverlayPath)path result:(void (^)(NSData *data, NSError *error))result

    if (!result) 
        return;
    

    // Cache
    // ...
    if (cache) 
        // ...      
     else 
        NSURLRequest *request = [NSURLRequest requestWithURL:[self URLForTilePath:path]];
        [NSURLConnection sendAsynchronousRequest:request queue:self.operationQueue completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) 
            // Caching mechanism
            // ...

            result(data, connectionError);
        ];