如何从UIImagePicker中保存UIImage在Documents文件夹中，并获取路径以保存在Swift中的Core Data中的路径

Question

I'm building my first Swift application. In it, the user needs to be able to choose an image from the iPhone's photo library. Then I want to save this image to keep permanently for use in other parts of the app.

I know it is possible to convert a UIImage to NSData and save as binary data in Core Data, but I have read that it is a bad idea to store Binary Large Objects, such as images directly in Core Data.

I have seen it suggested that you should save the image file in the Documents folder and then just save a string for the file path in Core Data. But I haven't seen an actual example of the code snippet needed to do this.

Steps to accomplish:

1. get UIImage from image picker. (this part I've got working)
2. save the image data in Documents folder
3. get string value for the file path to Documents folder
4. save this string in Core Data
5. Do steps 2-4 in reverse elsewhere in the app to use the stored image.

Here is the code for the UIImagePicker that I'm starting with:

@IBAction func openImagePicker(sender: AnyObject) {
    if UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.PhotoLibrary){
        imagePicker.delegate = self
        imagePicker.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
        imagePicker.allowsEditing = false
        self.presentViewController(imagePicker, animated: true, completion: nil)
    }
}

func imagePickerController(picker: UIImagePickerController!, didFinishPickingImage image: UIImage!, editingInfo: NSDictionary!)
{
self.dismissViewControllerAnimated(true, completion: nil)
myImageView.image = image
}

So the UIImage displayed in myImageView .image is what I need to do something with.

Answer 1

You can save your image with following code

    let imageData = NSData(data:UIImagePNGRepresentation(wineImage.image))
    let paths = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.UserDomainMask, true)
    var docs: String = paths[0] as! String
    let fullPath = docs.stringByAppendingPathComponent("yourNameImg.png")
    let result = imageData.writeToFile(responseData, atomically: true)

Inside fullPath you'll find the complete path, the image will be stored in app's document dir.