objective-c - 将地理坐标转换为 custon=m UIView 上的 CGPoint

Question

我正在构建一个应用程序，其中一个功能是在自定义 UIImageView 上推送地理坐标。我数学不好，所以我似乎无法获得正确的值(value)观。这就是我正在做的:

我有一张 2048x2048 的图像，我把它放在 UIScrollView 中，当我得到坐标时，假设是“Sydney -33.856963, 151.215219”，我将它们转换成 UIView坐标(x，y)

- (void)viewDidLoad
{
    [super viewDidLoad];
    scrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(0, 0, self.view.frame.size.width,self.view.frame.size.height)];
    scrollView.delegate = self;
    scrollView.showsVerticalScrollIndicator = YES;
    scrollView.scrollEnabled = YES;
    scrollView.userInteractionEnabled = YES;
    [scrollView setBounces:NO];
    scrollView.minimumZoomScale = 0.5;
    scrollView.maximumZoomScale = 100.0;


    mainImageView = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, IMAGE_SIZE, IMAGE_SIZE)];
    mainImageView.image = [UIImage imageNamed:@"map.jpg"];
    mainImageView.contentMode = UIViewContentModeScaleAspectFit;
    tipScroll.contentSize = CGSizeMake(IMAGE_SIZE, IMAGE_SIZE);


    [scrollView addSubview:mainImageView];
    [self.view addSubview:scrollView];

    NSString* fileContents = @"-33.856963,151.215219";
    NSArray* pointStrings = [fileContents componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];

    for (int i = 0; i<[pointStrings count]; i++) {
        NSArray* latLonArr = [currentPointString componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@","]];
        [self getCoordinates:latLonArr];

    }

 }  
-(void)getCoordinates:(NSArray *)latLonArr{

    double comparatorWidth = IMAGE_SIZE/360.0f;
    double comparatorHeight = IMAGE_SIZE/180.0f;


    double Xl = [[latLonArr objectAtIndex:1] doubleValue]; //151.215219
    double Yl = [[latLonArr objectAtIndex:0] doubleValue]; //-33.856963

    coordX = (Xl+180.0f)*comparatorWidth;
    coordY = (90.0f-Yl)*comparatorHeight;

    UIImage *image=[UIImage imageNamed:[NSString stringWithFormat:@"star.png"]];

    imageView=[[UIImageView alloc] init];

    [imageView setFrame:CGRectMake(coordX,coordY,10,10)];

    [imageView setImage:image];
    [scrollView addSubview:imageView];
}

我离中心坐标 (0,0) 越远，点就越不准确。如果我有西非某个城市的坐标，它就在现场，但悉尼就差很多了。我怎样才能解决这个问题？

Answer 1

我认为问题是地球不是平的。这意味着您不能简单地将地理坐标转换为 View 的二维系统。 http://en.wikipedia.org/wiki/Geographic_coordinate_system

检查此问题和正确答案: Converting longitude/latitude to X/Y coordinate