带有NSURLConnection的CATiledLayer的多个图像

Question

我正在尝试从服务器提取图像并使用CATiledLayer显示它们。 然而，图像似乎已损坏（它们有一些随机的空白点），我的猜测是因为多个连接可能已将其数据保存到同一个变量。所以我尝试使用NSMutableDictionary来跟踪特定NSURLConnection将NSMutableData保存到哪个NSMutableData实例。无论如何，事情只会变得更糟，因为现在只出现了空白的瓷砖。

h。档案：

#import <UIKit/UIKit.h>

@interface KlotsideVaade : UIView <NSURLConnectionDelegate> {
    NSMutableData *andmedServerist;
    NSMutableDictionary*andmedServeristDictionary;
    UIImage*minuPilt;

    NSString *imageName;
    BOOL      annotates;

    int Ymin;
    int Ymax;
    int Xmin;
    int Xmax;
}

@property(nonatomic) NSMutableData *andmedServerist;
@property(nonatomic) NSMutableDictionary*andmedServeristDictionary;
@property(nonatomic) UIImage*minuPilt;
@property (assign) BOOL annotates;

- (void)looYhendus;
- (id)initWithImage;
- (UIImage *)tileForScale;

@end

m。文件：

#import "KlotsideVaade.h"
#import <QuartzCore/CATiledLayer.h>

@implementation KlotsideVaade
@synthesize andmedServerist;
@synthesize andmedServeristDictionary;
@synthesize minuPilt;
@synthesize annotates;

+ (Class)layerClass {
    return [CATiledLayer class];
}

- (id)initWithImage
{
    if ((self = [super initWithFrame:CGRectMake(0, 0, 4096, 2992)])) {
        CATiledLayer *tiledLayer = (CATiledLayer *)[self layer];
        tiledLayer.levelsOfDetail = 4;
}
    return self;
}



- (void)drawRect:(CGRect)rect {
    CGContextRef context = UIGraphicsGetCurrentContext();

    CGFloat scale = CGContextGetCTM(context).a;

    CGSize tileSize = CGSizeMake(512, 374);

    tileSize.width /= scale;
    tileSize.height /= scale;

    int firstCol = floorf(CGRectGetMinX(rect) / tileSize.width);
    int lastCol = floorf((CGRectGetMaxX(rect)-1) / tileSize.width);
    int firstRow = floorf(CGRectGetMinY(rect) / tileSize.height);
    int lastRow = floorf((CGRectGetMaxY(rect)-1) / tileSize.height);

    for (int row = firstRow; row <= lastRow; row++) {
        for (int col = firstCol; col <= lastCol; col++) {
            Ymin=585000+col*10000/(4*scale);
            Ymax=585000+(col+1)*10000/(4*scale);
            Xmin=6500000-(row+1)*15000/(4*scale);
            Xmax=6500000-row*15000/(4*scale);

            UIImage *tile = [self tileForScale];
            CGRect tileRect = CGRectMake(tileSize.width * col, tileSize.height * row, tileSize.width, tileSize.height);

            tileRect = CGRectIntersection(self.bounds, tileRect);

            [tile drawInRect:tileRect];

            if (self.annotates) {
                [[UIColor whiteColor] set];
                CGContextSetLineWidth(context, 6.0 / scale);
                CGContextStrokeRect(context, tileRect);
            }
        }
    }
}

- (UIImage *)tileForScale;
{
    [self looYhendus];
    UIImage *image=minuPilt;
    return image;
}

- (void)looYhendus 
{  
    NSString *aadress = [NSString stringWithFormat:@"http://xgis.maaamet.ee/wms-pub/alus?version=1.1.1&service=WMS&request=GetMap&layers=MA-ALUSKAART&styles=default&srs=EPSG:3301&BBOX=%d,%d,%d,%d&width=%d&height=%d&format=image/png",Ymin,Xmin,Ymax,Xmax,512,374];
    NSURL *url = [[NSURL alloc] initWithString:aadress];
NSMutableURLRequest *theRequest = [NSMutableURLRequest requestWithURL:url];
        NSURLConnection *theConnection = [[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
    if( theConnection )
    {
        andmedServerist = [NSMutableData data];
        [andmedServeristDictionary setObject:andmedServerist forKey:[theConnection description]];
    }

    CFRunLoopRun();
}

-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
    andmedServerist=[andmedServeristDictionary objectForKey:[connection description]];
    [andmedServerist setLength: 0];
}

-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    andmedServerist=[andmedServeristDictionary objectForKey:[connection description]];
    [andmedServerist appendData:data];

}

-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"No connection" delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles:nil];

CFRunLoopStop(CFRunLoopGetCurrent());
}


-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    andmedServerist=[andmedServeristDictionary objectForKey:[connection description]];
    minuPilt = [UIImage imageWithData: andmedServerist];

    CFRunLoopStop(CFRunLoopGetCurrent());
}

@end