获取照片的属性信息

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{    //获取图片的NSURL 来源于AssetsLibrary.framework  #import <AssetsLibrary/AssetsLibrary.h>    NSURL *url = [info objectForKey:UIImagePickerControllerReferenceURL];        //ALAssetsLibrary 获取图片和视频    ALAssetsLibrary *library = [[ALAssetsLibrary alloc]init];        //根据url获取指定的图片  如果获取到了资源执行resultBlock，否则执行failureBlock    //ALAsset实例 代表一个图片或者视频    [library assetForURL:url resultBlock:^(ALAsset *asset){        //defaultRepresentation 获取资源文件的默认属性        //metadata 获取数据的数据，就是在默认属性中的数据，称之为元数据        NSDictionary *imageData = [[NSMutableDictionary alloc]initWithDictionary:asset.defaultRepresentation.metadata];        //kCGImagePropertyGPSDictionary 关于GPS的字典数据  来源于ImageIO.framework  #import <ImageIO/ImageIO.h>        NSDictionary *gpsData = [imageData objectForKey:(NSString *)kCGImagePropertyGPSDictionary];        //打印纬度        NSLog(@"%@",[gpsData objectForKey:@"Altitude"]);    }failureBlock:^(NSError *error){        NSLog(@"error:%@",error);    }];}