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PCLStorage NuGetPackage not allow creating folder or file on device

I have a problem with creating folder with nuget package PCLStorage, I cannot create folder.
Nothing appear inside my files folder. I,m using my device not emulator there is android version 8.0
public async Task WriteDataAsync(string filename, string data)
{
string folderName = "SignatureSotrage";
IFolder folder = FileSystem.Current.LocalStorage;
folder = await folder.CreateFolderAsync(folderName, CreationCollisionOption.ReplaceExisting);
}
Here is a code where I run this function:
public ICommand AddCustomerCommand => new Command(async () =>
{
Signature = await SignatureFromStream();
// Signature should be != null
var customer = new Customer()
{
FullName = this.FullName,
IsAccepted = this.IsAccepted,
Birthday = this.Birthday
};
if(Signature != null)
{
customer.Image = this.Signature.ToString();
}
else
{
await Application.Current.MainPage.DisplayAlert("Błąd", "Nie wszystkie pola zostały poprawnie wypełnione", "OK");
return;
}
await DependencyService.Get<IFileHelper>().WriteDataAsync("signature.txt", "this is file");
//_context.Customers.Add(customer);
//_context.SaveChanges();
});

did you debug your code & check if the file/folder is actually getting created by your code or else it enters the catch block and goes with the normal flow?
Check for UserPermissions every time for reading & write permission before doing any operations on the storage. You can add the Nugget packet Plugin.Permission it handles everything for you, it adds both the permission in the manifest.
For checking user permissions always try calling CheckForStoragePermissions() before performing any operations on storage.(*DialogService is CustomDialogBox)
if( !await CheckForStoragePermissions() )
{
DialogService.Alert("Invalid Permission", "User declined permission for this action");
return;
}
private async Task<bool> CheckForStoragePermissions()
{
PermissionStatus storagePermissionStatus = await CrossPermissions.Current.CheckPermissionStatusAsync(Permission.Storage);
if (storagePermissionStatus != PermissionStatus.Granted)
{
Dictionary<Permission, PermissionStatus> storagePermissionResult = await CrossPermissions.Current.RequestPermissionsAsync(Permission.Storage);
if (storagePermissionResult.ContainsKey(Permission.Storage))
{
storagePermissionStatus = storagePermissionResult[Permission.Storage];
}
}
return storagePermissionStatus == PermissionStatus.Granted;
}

I test the sample code on GitHub. https://github.com/dsplaisted/PCLStorage
Based on my test the folder path would like:
/data/user/0/PCLStorage.Test.Android/files/
It is a internal storage. You couldn't see the files without root permission. https://learn.microsoft.com/en-us/xamarin/android/platform/files/#working-with-internal-storage
If you want to see the files in internal storage, you could use adb tool. Please refer to the way in the link. How to write the username in a local txt file when login success and check on file for next login?

How can I open a .pdf file in the browser from a Xamarin UWP project?

I have a Xamarin Project where I generate a .pdf file from scratch and save it in my local storage. This works perfectly fine and can find it and open it in the disk where I saved it. However, I need to open the .pdf file immediately after creation programmatically.
I already tried different variations using Process and ProcessStartInfo but these just throw errors like "System.ComponentModel.Win32Exception: 'The system cannot find the file specified'" and "'System.PlatformNotSupportedException'".
This is basically the path I am trying to open using Process.
var p = Process.Start(#"cmd.exe", "/c start " + #"P:\\Receiving inspection\\Inspection Reports\\" + timestamp + ".pdf");
I also tried ProcessStartInfo using some variations but I'm getting the same errors all over and over.
var p = new Process();
p.StartInfo = new ProcessStartInfo(#"'P:\\Receiving inspection\\Inspection Reports\\'" + timestamp + ".pdf");
p.Start();

The better way is that use LaunchFileAsync method to open file with browser. You could create FileLauncher DependencyService to invoke uwp LaunchFileAsync method from xamarin share project.
Interface
public interface IFileLauncher
{
Task<bool> LaunchFileAsync(string uri);
}
Implementation
[assembly: Dependency(typeof(UWPFileLauncher))]
namespace App14.UWP
{
public class UWPFileLauncher : IFileLauncher
{
public async Task<bool> LaunchFileAsync(string uri)
{
var file = await Windows.Storage.StorageFile.GetFileFromPathAsync(uri);
bool success = false;
if (file != null)
{
// Set the option to show the picker
var options = new Windows.System.LauncherOptions();
options.DisplayApplicationPicker = true;
// Launch the retrieved file
success = await Windows.System.Launcher.LaunchFileAsync(file, options);
if (success)
{
// File launched
}
else
{
// File launch failed
}
}
else
{
// Could not
}
return success;
}
}
}
Usage
private async void Button_Clicked(object sender, EventArgs e)
{
await DependencyService.Get<IFileLauncher>().LaunchFileAsync("D:\\Key.pdf");
}
Please note if you want to access D or C disk in uwp, you need add broadFileSystemAccess capability. for more please refer this .
Update
If the UWP files are network based, not local zone based, you could use Xamarin.Essentials to open file with browser. And you must specify the privateNetworkClientServer capability in the manifest. For more please refer this link.

How to open documents and images using launcher in windows phone 8

I am creating windows phone 8 app, I have to open docs and images using code or launcher. The problem is that those documents are not opening those are not created in MS Office, I am getting error like:
"Document has been damaged, cant open" and
"File Format doesn't recognized"
My code is here:
string file = "Test.xls";
var filerun = await ApplicationData.Current.LocalFolder.CreateFileAsync(file);
await Launcher.LaunchFileAsync(await ApplicationData.Current.LocalFolder.GetFileAsync(file));

Try this code
string uriToLaunch = #"http://www.contoso.com/SomeFile.docx";
var uri = new Uri(uriToLaunch);
async void DefaultLaunch()
{
// Set the URI’s content type
var options = new Windows.System.LauncherOptions();
options.ContentType = "application/vnd.ms-word.document.12";
// Launch the URI with the content type
var success = await Windows.System.Launcher.LaunchUriAsync(uri, options);
if (success)
{
// URI launched
}
else
{
// URI launch failed
}
}
Search for the right MIME type of your file.

How to dowload/upload file onto a users onedrive

I am in a Highschool club where we create windows store apps. I am in charge of the code that allows the user to either download files from their online onedrive storage, or upload files. So far I have successfully logged the user in and gained access to onedrive and display the users name with the following code:
private async void LoadProfile()
{
bool connected = false;
string text = "No Error:";
try
{
var authClient = new LiveAuthClient();
LiveLoginResult result = await authClient.LoginAsync(new List<string>() {"wl.signin", "wl.skydrive"});
if (result.Status == LiveConnectSessionStatus.Connected)
{
connected = true;
var connectClient = new LiveConnectClient(result.Session);
var meResult = await connectClient.GetAsync("me");
dynamic meData = meResult.Result;
Textblock_profilename.Text = meData.name;
}
}
catch (LiveAuthException ex)
{
//Set text to corresponding error
text = ex.ToString();
}
catch (LiveConnectException ex)
{
//Set text to corresponding error
text = ex.ToString();
}
if (text[0].ToString() != "N")
{
var dialog = new Windows.UI.Popups.MessageDialog(text);
await dialog.ShowAsync();
}
}
I gained the code from the following MSDN tutorial: http://msdn.microsoft.com/en-us/library/dn631823.aspx
However when I try to follow the next step, downloading and uploading files, I cannot get it to work. Right now I am just trying to press a button, and have the code download a test file:
private async void Button_downloadFile_Click(object sender, RoutedEventArgs e)
{
try
{
LiveDownloadOperation operation = await connectClient.CreateBackgroundDownloadAsync("skydrive/documents/enter_path");
var result = await operation.StartAsync();
//DO SOMETHING WITH RESULT HERE
}
catch
{
// Handle any errors.
}
}
However this code throws the following errors:
This is straight from the MSDN tutorial, and can't figure out how to fix the error. My best guess is I'm missing a "using" statement, but can't figure out what I am missing. Thanks for any and all help!

Make sure you're updated to use the Live SDK 5.6 binary. Be sure to let us know if you have any other problems with OneDrive integration!

Open A PDF file on button click

I want to open a pdf file in winRT app(metro style app) by clicking on a button the file should open in windows8 default reader. I tried this code, where button click method name is DefaultLaunch_click():
async void DefaultLaunch_click()
{
// Path to the file in the app package to launch
string imageFile = #"images\ret.png";
// Get the image file from the package's image directory
var file = await Windows.ApplicationModel.Package.Current.InstalledLocation.GetFileAsync(imageFile);
if (file != null)
{
// Set the recommended app
var options = new Windows.System.LauncherOptions();
options.PreferredApplicationPackageFamilyName = “Contoso.FileApp_8wknc82po1e”;
options.PreferredApplicationDisplayName = “Contoso File App”;
// Launch the retrieved file pass in the recommended app
// in case the user has no apps installed to handle the file
bool success = await Windows.System.Launcher.LaunchFileAsync(file, options);
if (success)
{
// File launched
}
else
{
// File launch failed
}
}
else
{
// Could not find file
}
}
It worked for .png file but i want for .pdf file i replaced 1.png with M.pdf(after including it in images folder) and set the build content of M.pdf to Embedded Resource , run the program but it showed error that
**The system cannot find the file specified. (Exception from HRESULT: 0x80070002)**

This code works for me after I set PDF file build action to content and copy always to output directory.
private async void Button_Click(object sender, RoutedEventArgs e)
{
string imageFile = #"images\somepdffile.pdf";
// Get the image file from the package's image directory
var file = await Windows.ApplicationModel.Package.Current.InstalledLocation.GetFileAsync(imageFile);
if (file != null)
{
bool success = await Windows.System.Launcher.LaunchFileAsync(file, options);
if (success)
{
// File launched
}
else
{
// File launch failed
}
}
else
{
// Could not find file
}
}