如何从UIImagePickerController拍摄的照片和视频中获取日期？

Question

如果呈现的源图像类型为.Camera （Swift）的UIImagePickerController ，如何在UIImagePickerControllerDelegate方法中获取图像或视频的拍摄日期（或开始录制，对于视频而言）。

Answer 1

You have to access the info and extract the meta data and extract the date from that:

- (void)imagePickerController:(nonnull UIImagePickerController *)picker didFinishPickingMediaWithInfo:(nonnull NSDictionary<NSString *,id> *)info {
    NSString* meta = [[[info objectForKey:UIImagePickerControllerMediaMetadata] objectForKey:@"{TIFF}"] objectForKey:@"DateTime"];
    NSDateFormatter *form = [[NSDateFormatter alloc] init];
    form.dateFormat = @"yyyy:MM:dd HH:mm:ss";
    NSDate* date = [form dateFromString:meta];

    [picker dismissViewControllerAnimated:true completion:^{}];
}

Answer 2

Use the imagePickerController(_picker, didFinishPickingMediaWithInfo info) method of the UIImagePickerControllerDelegate protocol.

func imagePickerController(_ picker: UIImagePickerController,
  didFinishPickingMediaWithInfo info: [NSObject : AnyObject]) {
      let metaDataDict = info.valueForKey(UIImagePickerControllerMediaMetadata) as? NSDictionary
      // print metaDataDict to see it's keys and values
      println("meta data = \(metaDataDict.description)")
}

You can then determine the key for the date the photo was taken (note that [UIImagePickerControllerMediaMetadata][1] is only for photos).

Answer 3

First you present you UIImagePickerController and when you get the callback imagePickerController(_:didFinishPickingMediaWithInfo:) grab the info dictionary and extract the date info:

func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [NSObject : AnyObject]) {
    if let url = info[UIImagePickerControllerMediaURL] as? NSURL { // Its possible that there will not be a date present
    let assetsLibrary = ALAssetsLibrary()
    assetsLibrary.assetForURL(url, resultBlock: { (asset: ALAsset!) -> Void in
        if let date = asset.valueForProperty(ALAssetPropertyDate) as? NSDate {
            print("\(date)\n")
        }

        }) { (error: NSError!) -> Void in
            // Handle error
        }
    }
}

Be sure to link with AssetsLibrary .

Presenting can be done like so:

let picker = UIImagePickerController()
picker.sourceType = .PhotoLibrary
picker.delegate = self
self.presentViewController(picker, animated: true, completion: nil)