Objective c MapView上的注释：坐标

我有两个NSString地址和键，它们以数字3456789的形式包含坐标经度和纬度…：

NSString *key = [allKeys objectAtIndex:i];
NSObject *obj = [DictionaryMap objectForKey:key];

NSString *address = [NSString stringWithFormat:@"%@", obj];


CLLocationCoordinate2D anyLocation;

anyLocation.latitude = [address doubleValue];

anyLocation.longitude  = [key doubleValue];

MKPointAnnotation *annotationPoint2 = [[MKPointAnnotation alloc] init]; annotationPoint2.coordinate = anyLocation;

annotationPoint2.title = @"Event";
annotationPoint2.subtitle = @"Microsoft's headquarters2";
[mapView addAnnotation:annotationPoint2]; 

…但我不明白为什么它不在写坐标的同一点上绘制。我认为这是行不通的：

[address doubleValue]  

所以我试着用：

location.latitude = NSNumber/NSString

但它给出了一个错误

更新：

考虑到以下情况：

 UILongPressGestureRecognizer *longPressGesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPressGesture:)];
[self.mapView addGestureRecognizer:longPressGesture];

[mapView.userLocation setTitle:@"I am here"];

……然后

-(void)handleLongPressGesture:(UIGestureRecognizer*)sender {
// This is important if you only want to receive one tap and hold event
if (sender.state == UIGestureRecognizerStateEnded)
{
    [self.mapView removeGestureRecognizer:sender];
}
else
{

    // Here we get the CGPoint for the touch and convert it to latitude and longitude coordinates to display on the map
    CGPoint point = [sender locationInView:self.mapView];
    CLLocationCoordinate2D locCoord = [self.mapView convertPoint:point toCoordinateFromView:self.mapView];
    // Then all you have to do is create the annotation and add it to the map

MKPointAnnotation *annotationPoint = [[MKPointAnnotation alloc] init]; annotationPoint.coordinate = locCoord;

    annotationPoint.title = @"Microsoft";
    annotationPoint.subtitle = @"Microsoft's headquarters";
    [mapView addAnnotation:annotationPoint];

NSString *latitude = [[NSString alloc] initWithFormat:@"%f",locCoord.latitude];


    NSString *longitude = [[NSString alloc] initWithFormat:@"%f", locCoord.longitude];

    NSLog(latitude);
    NSLog(longitude);


    [[NSUserDefaults standardUserDefaults]setObject:latitude forKey:@"FolderLatitude"];
     [[NSUserDefaults standardUserDefaults]setObject:longitude forKey:@"FolderLongitude"];
}
}

---

…然后我将坐标保存在一个JSON文件中，然后从文件中读取它们。

打印出您为lat/lon设置的值。听起来这些值没有正确地转换为double。如果字符串不是xxx.xxx格式，那么在调用doubleValue时，它们将无法正确转换为double。

最后我明白了：这是正确的工作方式：

NSString *myString = (string initialization here)

float stringFloat = [myString floatValue];

anyLocation.longitude = stringFloat;

---

NSNumber/NSString在ObjC中没有任何意义。怎么了？你认为会发生什么？你能解释一下你想要完成的总体目标吗？不太清楚。不，我只是说我先用了一个NSNumber不兼容的参数strong，然后是一个NSString相同的错误lat:44.840291，lon:17.841797你是这样打印出来的吗？NSLog@lat：%@，lon:%@，address，keyNSString*纬度=[[NSString alloc]initWithFormat:@%f，locCoord.latitude]。。。。。北纬；哦抱歉：CGPoint=[sender locationInView:self.mapView]；CLLocationCoordinate2D locCoord=[self.mapView convertPoint:point to CoordinateFromView:self.mapView]。。。在HandleLongPressGesture下，您可能需要将最后一个参数更改为该点来自的任何视图