Download path in Xamarin iOS - xamarin

Question

I am using Xamarin.Forms and written the code to download the file for the iOS
platform. It is downloading the file successfully without any error. But after downloading it, I am not able to find the downloaded file in my apple device.
During debugging I found that it is showing
/var/mobile/Containers/Data/Application/1234567A-B8CD-9EF9-C850-9G73587DC7C/Documents/XF_Downloads/hausmann_abcd.jpg
path. So at which location file get saved? below is the image for the same.
I have written below code for this
public class IosDownloader : IDownloader
{
public event EventHandler<DownloadEventArgs> OnFileDownloaded;
public void DownloadFile(string url, string folder)
{
string pathToNewFolder = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Personal), folder);
Directory.CreateDirectory(pathToNewFolder);
try
{
WebClient webClient = new WebClient();
webClient.DownloadFileCompleted += new AsyncCompletedEventHandler(Completed);
string pathToNewFile = Path.Combine(pathToNewFolder, Path.GetFileName(url));
webClient.DownloadFileAsync(new Uri(url), pathToNewFile);
}
catch (Exception ex)
{
if (OnFileDownloaded != null)
OnFileDownloaded.Invoke(this, new DownloadEventArgs(false));
}
}
private void Completed(object sender, AsyncCompletedEventArgs e)
{
if (e.Error != null)
{
if (OnFileDownloaded != null)
OnFileDownloaded.Invoke(this, new DownloadEventArgs(false));
}
else
{
if (OnFileDownloaded != null)
OnFileDownloaded.Invoke(this, new DownloadEventArgs(true));
}
}
}

Answer 1

When a file is saved on an application it is a temporary url within the app's sandbox. To make this image file be publicly accessible through Apple's Photos, You'll have to use native code to do a request to add a new PHImageAsset to the photos library.
In forms you would need to access the native frameworks and therefore run native code. There are plenty of examples of doing this online if you don't know how to already. But here is an introduction if you want to run native code within a shared code framework. https://learn.microsoft.com/en-us/xamarin/xamarin-forms/app-fundamentals/dependency-service/introduction
Here is a sample of taking that temp file URL and saving it to Photos Framework once you can code w/ native Xamarin.iOS frameworks:
public void AddImageUrlToPhotosLibrary(string urlToSaveToPhotos)
{
PHPhotoLibrary.SharedPhotoLibrary.PerformChanges(() => {
//This is bound to native https://developer.apple.com/documentation/photokit/phassetchangerequest/1624060-creationrequestforasset
//Parameter is an NSURL of path to image.
PHAssetChangeRequest.FromImage(new NSUrl(urlToSaveToPhotos));
}, (completed, error) => {
if (completed)
{
if (error != null)
{
Console.WriteLine($"Failed saving image asset {error.LocalizedDescription}");
} else
{
Console.WriteLine($"Successfully saved image to photos library.");
}
}
});
}

Answer 2

I am not able to find the downloaded file in my apple device.
If you use a simulator, you can directly find the folder in the mac by entering the path in the
your mac --> select Finder --> Then open the Go menu --> Click Go to Folder as I described in this thread:
Where can I find the MyDocuments folder on iPhone Simulator?
If you installed the app in a real device. You can browse the file in
Xcode --> Devices and Simulators --> download container as described in this thread:
Browse the files created on a device by the iOS application I'm developing, after downloading the container, you can right click it and choose Show Package Contents. Then you can see the folders.
You can also access the file by the path in the project.