我需要从 UIImagePickerController 选择的照片中获取 GPS 数据并提取要在 UIMapKit 中使用的照片的位置，我在 stackoverflow 和 Google 中尝试了一些示例代码，但没有一个对我有用！我使用的照片包含纬度和经度数据，但它总是返回 nil 并出现这个致命错误：“在展开可选值时意外发现 nil”，我在模拟器上测试应用程序是否会导致任何问题？我考虑了各种各样的问题，我哪里做错了？这是代码
func imagePickerController(picker: UIImagePickerController!, didFinishPickingMediaWithInfo info: NSDictionary!) {
if picker.sourceType == UIImagePickerControllerSourceType.PhotoLibrary {
let url: AnyObject? = info[UIImagePickerControllerReferenceURL] as? NSURL
let library = ALAssetsLibrary()
library.assetForURL(url as NSURL, resultBlock: { (asset: ALAsset!) -> Void in
if asset != nil {
var assetRep: ALAssetRepresentation = asset.defaultRepresentation()
var metaData: NSDictionary = assetRep.metadata()
let location = metaData.objectForKey(ALAssetPropertyLocation) as CLLocation!
let lat = location.coordinate.latitude
let long = location.coordinate.longitude
}
}, failureBlock: { …