Develop Reference

Xamarin.Essentials Share drawable

I'm trying to share a local image loacted in my Resources/Drawables folder in Android.
I'm using Xamarin and the Xamarin.Essentials plugin.
So there is this function:
await Share.RequestAsync(new ShareFileRequest
{
Title = Title,
File = new ShareFile(file)
});
So for the File I need the Path to the File from the Drawable Folder.
I have tried so much variations.
For example:
var file = Android.Net.Uri.Parse("android.resource://" + Android.App.Application.Context.PackageName + "/" + Resource.Drawable.image).Path;
But I always get an error, that the file is not found.
What I'm doing wrong?
Thanks in advance

Because Resources don't have file paths, as #Jason said I saved the image in another accesible file.
So I don't know if this is the best solution, but it works for me:
Drawable drawable = ResourcesCompat.GetDrawable(Resources, Resource.Drawable.image, null);
Bitmap bitmap = ((BitmapDrawable)drawable).Bitmap;
byte[] imgByteArray;
using (var stream = new MemoryStream())
{
bitmap.Compress(Bitmap.CompressFormat.Png, 0, stream);
imgByteArray = stream.ToArray();
}
var file = System.IO.Path.Combine(FileSystem.CacheDirectory, "share.png");
File.WriteAllBytes(file, imgByteArray);
await Share.RequestAsync(new ShareFileRequest
{
Title = "Share",
File = new ShareFile(file)
});

FileOpenPicker - how to specify Custom Start Path

can you tell me how to specify custom start path in file open picker class??
'openPicker.SuggestedStartLocation' does not shown custom path option.
thank you for reading!
FileOpenPicker openPicker = new FileOpenPicker();
openPicker.ViewMode = PickerViewMode.Thumbnail;
openPicker.SuggestedStartLocation = PickerLocationId.Desktop;
openPicker.FileTypeFilter.Add(".xml");
StorageFile file = await openPicker.PickSingleFileAsync();
if(file!=null)
{
var stream = await file.OpenAsync(Windows.Storage.FileAccessMode.Read);
}
else
{
//
}

I am afraid you cannot specify a custom start path for that. You can only use the path which are mentioned over there. You can read about it over here

Save File Thumbnail as image in windows runtime

I want to get Thumbnail of files stored in Videos folder and save them as image in my local folder .
here is my code to get files .
var v = await KnownFolders.VideosLibrary.GetFilesAsync();
foreach (var file in v)
{
var thumb = await file.GetScaledImageAsThumbnailAsync(Windows.Storage.FileProperties.ThumbnailMode.SingleItem);
BitmapImage Img = new BitmapImage();
Img.SetSource(thumb);
await ApplicationData.Current.LocalFolder.CreateFolderAsync("VideoThumb");
var imageFile = await ApplicationData.Current.LocalFolder.CreateFileAsync(
"VideoThumb\\" + file.Name, CreationCollisionOption.FailIfExists);
var fs = await imageFile.OpenAsync(FileAccessMode.ReadWrite);
//I don't know how to save thumbnail on this file !
}
my project is a Windows Phone 8.1 Runtime C# app .

There are couple of things you need to handle:
you don't need BitmapImage, as thumbnail provides a stream which you can write directly to file,
you are not handling the case when create file method fails (file exists),
create folder method will throw exception as the folder is created (or already exists) with the first file in foreach. Rather than that, create/open folder outside foreach,
also creating image with file.Name is not a good idea, hence those are videos and their extension will likely be mp4/mpg/other not jpg/png/other,
remember to add capabilities in packageappx.manifest file.
I think the below code should do the job:
private async Task SaveViedoThumbnails()
{
IBuffer buf;
StorageFolder videoFolder = await ApplicationData.Current.LocalFolder.CreateFolderAsync("VideoThumb", CreationCollisionOption.OpenIfExists);
Windows.Storage.Streams.Buffer inputBuffer = new Windows.Storage.Streams.Buffer(1024);
var v = await KnownFolders.VideosLibrary.GetFilesAsync();
foreach (var file in v)
{
var thumb = await file.GetScaledImageAsThumbnailAsync(Windows.Storage.FileProperties.ThumbnailMode.SingleItem);
var imageFile = await videoFolder.CreateFileAsync(file.DisplayName + ".jpg", CreationCollisionOption.ReplaceExisting);
using (var destFileStream = await imageFile.OpenAsync(FileAccessMode.ReadWrite))
while ((buf = (await thumb.ReadAsync(inputBuffer, inputBuffer.Capacity, Windows.Storage.Streams.InputStreamOptions.None))).Length > 0)
await destFileStream.WriteAsync(buf);
}
}

Bind images to listbox with datatemplate from app package folder

Hi I need bind images to listbox but when I try it I get FILE NOT FOUND but file is stored in application package in folder layoutGraphics. I try put files to default folder but I get same result anyone know what is bad?
var file = await Windows.Storage.ApplicationData.Current.LocalFolder.GetFileAsync("ms-appx:///layoutGraphics/offline.png");
var fileStream = await file.OpenAsync(Windows.Storage.FileAccessMode.Read);
var img = new BitmapImage();
img.SetSource(fileStream);
ImgSource = img;
// property
private BitmapImage _imgSource;
public BitmapImage ImgSource
{
get { return _imgSource; }
set
{
_imgSource = value;
OnPropertyChanged("MyDatasMessagesUserList");
}
}
Or anyone know better solution how I can bind imagess from app folder to my listbox with datatemplate?

Windows.Storage.ApplicationData.Current.LocalFolder is retriving file from the application storage not the package. For the package folder you need to use Windows.ApplicationModel.Package.Current.InstalledLocation. Also the GetFileAsync take just the name of a file not a full path.
Here is the code to acomplish what you want:
var layoutGraphiceFolder = await Windows.ApplicationModel.Package.Current.InstalledLocation.GetFolderAsync("layoutGraphics")
var file=await layoutGraphiceFolder.GetFileAsync("offline.png");
Another way to do it with the full path is:
var file=await StorageFile.GetFileFromApplicationUriAsync(new Uri("ms-appx:///layoutGraphics/offline.png"));

How do I save an image url to a local file in Windows 8 c#

Basically, the app displays images, and I want the user to be able to select an image for download and store it locally.
I have the URL, but I don't know how to use that url in conjunction with the filepicker.

You can use the following method to download the file from a given Uri to a file selected with a file picker:
private async Task<StorageFile> SaveUriToFile(string uri)
{
var picker = new FileSavePicker();
// set appropriate file types
picker.FileTypeChoices.Add(".jpg Image", new List<string> { ".jpg" });
picker.DefaultFileExtension = ".jpg";
var file = await picker.PickSaveFileAsync();
using (var fileStream = await file.OpenStreamForWriteAsync())
{
var client = new HttpClient();
var httpStream = await client.GetStreamAsync(uri);
await httpStream.CopyToAsync(fileStream);
fileStream.Dispose();
}
return file;
}

I think you can always read the file as a stream and save it bit by bit on the local machine. But I need to say that I've done this many times in JAVA, I never needed to check this in C# :)

SaveFileDialog myFilePicker = new SaveFileDialog();
//put options here like filters or whatever
if (myFilePicker.ShowDialog() == DialogResult.OK)
{
WebClient webClient = new WebClient();
webClient.DownloadFile("http://example.com/picture.jpg", myFilePicker.SelectedFile);
}