I'm working in a UWP app, at some point, the user has the chance to save an image (done) by now I only let the user know that the save operation was done by a "messageDialog", this is my code:
var savePicker = new Windows.Storage.Pickers.FileSavePicker();
savePicker.SuggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.DocumentsLibrary;
savePicker.FileTypeChoices.Add("QR Code", new List<string>() { ".png", ".jpg", ".jpeg", ".jpe", ".bmp" });
savePicker.SuggestedFileName = "QR_01";
Windows.Storage.StorageFile file = await savePicker.PickSaveFileAsync();
if (file != null)
{
Windows.Storage.CachedFileManager.DeferUpdates(file);
await Windows.Storage.FileIO.WriteBytesAsync(file, _bytes3);
Windows.Storage.Provider.FileUpdateStatus status = await Windows.Storage.CachedFileManager.CompleteUpdatesAsync(file);
if (status == Windows.Storage.Provider.FileUpdateStatus.Complete)
{
var messageDialog = new Windows.UI.Popups.MessageDialog("File saved on: " + file.Path);
await messageDialog.ShowAsync();
}
else
{
//this.textBlock.Text = "File " + file.Name + " couldn't be saved."; not defined by now
}
done = true;
}
else
{
this.textBlock.Text = "operation canceled";
done = false;
}
This works good so far but I want to be sure that the file is already there after the "WriteBytesAsync" method. So, this is the thing, the users can save the image in any directory they have acces to so I can't check (or read) the folder they choose afer that because I don't have acces permission afer save the file. I have tryed something like this to get folder access:
string savePath = System.IO.Path.GetDirectoryName(file.Path);
Windows.Storage.StorageFolder saveFolder = await Windows.Storage.StorageFolder.GetFolderFromPathAsync(savePath);
In order to use the "GetFileAsync" to check the file or the "FutureAccessList" for a future access but since I have file access permisions to any directory it fails, and because of that I can't use any of the solution in here: UWP Check If File Exists
My Questions are:
1.- Is there a way to check if the file was saved or successfully written afer the user click the "Save" button?
2.- Does the "WriteBytesAsync" method is enough to ensure taht the file was saved?? according to the info FileIO.WriteBytesAsync(IStorageFile, Byte[]) Method, it don't throw any exception.
but I want to be sure that the file is already there after the "WriteBytesAsync" method.
For you requirement, you could use GetFileFromPathAsync method to get the file, if the file is not null, means that the file is exist. And please note if you want to above method, you need add broadFileSystemAccess capability, and open it in your system setting. For more please refer this.
Windows.Storage.CachedFileManager.DeferUpdates(file);
await Windows.Storage.FileIO.WriteBytesAsync(file, new byte[3]);
var temp = await StorageFile.GetFileFromPathAsync(file.Path);
if(temp != null)
{
}
else
{
}
Does the "WriteBytesAsync" method is enough to ensure taht the file was saved??
Yep, WriteBytesAsync method need to pass StorageFile parameter. if the file parameter is not null means it has created in the folder. Or it will throw null exception.
Related
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?
I am currently working on a Windows 10 UWP App.
The App needs to Check if a certain PDF File exists called "01-introduction", and if so open it.
I already have the code for if the file does not exist.
The Code Below is what i currently have:
try
{
var test = await DownloadsFolder.CreateFileAsync("01-Introduction.pdf", CreationCollisionOption.FailIfExists);
}
catch
{
}
This code Does not work correctly because to check if the file exists here, I attempt to create the file. However if the file does not already exist an empty file will be created. I do not want to create anything if the file does not exist, just open the PDF if it does.
If possible, i would like to look inside a folder which is in the downloads folder called "My Manuals".
Any help would be greatly appreciated.
public async Task<bool> IsFilePresent(string fileName)
{
var item = await ApplicationData.Current.LocalFolder.TryGetItemAsync(fileName);
return item != null;
}
But not support Win8/WP8.1
https://blogs.msdn.microsoft.com/shashankyerramilli/2014/02/17/check-if-a-file-exists-in-windows-phone-8-and-winrt-without-exception/
There are two methods
1) You can use StorageFolder.GetFileAsync() as this is also supported by Windows 8.1 and WP 8.1 devices.
try
{
StorageFile file = await DownloadsFolder.GetFileAsync("01-Introduction.pdf");
}
catch
{
Debug.WriteLine("File does not exits");
}
2) Or you can use FileInfo.Exists only supported for windows 10 UWP.
FileInfo fInfo = new FileInfo("01-Introduction.pdf");
if (!fInfo.Exists)
{
Debug.WriteLine("File does not exits");
}
System.IO.File.Exists is UWP way too. I test now in Windows IOT. it just works.
This helped me in my case:
ApplicationData.Current.LocalFolder.GetFileAsync(path).AsTask().ContinueWith(item => {
if (item.IsFaulted)
return; // file not found
else { /* process file here */ }
});
This worked for me running my UWP C# app on Windows 10...
StorageFolder app_StorageFolder = await StorageFolder.GetFolderFromPathAsync( #App.STORAGE_FOLDER_PATH );
var item = await app_StorageFolder.TryGetItemAsync(relative_file_pathname);
return item != null;
public override bool Exists(string filePath)
{
try
{
string path = Path.GetDirectoryName(filePath);
var fileName = Path.GetFileName(filePath);
StorageFolder accessFolder = StorageFolder.GetFolderFromPathAsync(path).AsTask().GetAwaiter().GetResult();
StorageFile file = accessFolder.GetFileAsync(fileName).AsTask().GetAwaiter().GetResult();
return file != null;
}
catch
{
return false;
}
}
You can use System.IO.File.
Example:
// If file located in local folder. You can do the same for other locations.
string rootPath = ApplicationData.Current.LocalFolder.Path;
string filePath = Path.Combine(rootPath, "fileName.pdf");
if (System.IO.File.Exists(filePath))
{
// File exists
}
else
{
// File doesn't exist
}
I'm doing a Win10 IoT Core UWP app and I have to check the file length instead of "Exists" because CreateFileAsync() already creates an empty file stub immediately. But I need that call before to determine the whole path the file will be located at.
So it's:
var destinationFile = await ApplicationData.Current.LocalFolder.CreateFileAsync("MyFile.wow", ...);
if (new FileInfo(destinationFile.Path).Length > 0)
return destinationFile.Path;
In this way System.IO.File.Exists(filePath) I cannot test DocumentLibrary
because KnownFolders.DocumentsLibrary.Path return empty string
Next solution is very slow await DownloadsFolder.GetFileAsync("01-Introduction.pdf")
IMHO the best way is collect all files from folder and check the file name exist.
List<StorageFile> storageFileList = new List<StorageFile>();
storageFileList.AddRange(await KnownFolders.DocumentsLibrary.GetFilesAsync(CommonFileQuery.OrderByName));
bool fileExist = storageFileList.Any(x => x.Name == "01-Introduction.pdf");
CreateFileSync exposes an overload that let's you choose what to do if an existing file with the same name has been found in the directory, as such:
StorageFile localDbFile = await DownloadsFolder.CreateFileAsync(LocalDbName, CreationCollisionOption.OpenIfExists);
CreationCollisionOption is the object that you need to set up. In my example i'm opening the file instead of creating a new one.
Based on another answer here, I like
public static async Task<bool> DoesFileExist(string filePath) {
var directoryPath = System.IO.Path.GetDirectoryName(filePath);
var fileName = System.IO.Path.GetFileName(filePath);
var folder = await StorageFolder.GetFolderFromPathAsync(directoryPath);
var file = await folder.TryGetItemAsync(fileName);
return file != null;
}
You can use the FileInfo class in this case. It has a method called FileInfo.Exists() which returns a bool result
https://msdn.microsoft.com/en-us/library/system.io.fileinfo.exists(v=vs.110).aspx
EDIT:
If you want to check for the files existence, you will need to create a StorageFile object and call one of the GetFile.... methods. Such as:
StorageFile file = new StorageFile();
file.GetFileFromPathAsync("Insert path")
if(file == null)
{
/// File doesn't exist
}
I had a quick look to find the download folder path but no joy, but the GetFile method should give you the answer your looking for
On Window 10, for me, this is the most "elegant" way:
private static bool IsFileExistent(StorageFile file)
{
return File.Exists(Path.Combine(file.Path));
}
Or, as an extension if you prefer and will use it widely:
static class Extensions
{
public static bool Exists(this StorageFile file)
{
return File.Exists(Path.Combine(file.Path));
}
}
I am new to Telerik controls, in my code I am trying to Upload excel file using RadAsync upload.
Code is working fine, but when user is trying to upload a file which is already opened in the background- I am getting javascript exception.
Is there is any way by which I can alert user in case file is already opened?
You can use OnClientFileUploadFailed event of Telerik RadAsync Upload.
Something like
function OnClientFileUploadFailed(sender, args) {
var upload = $find("<%= RadUpload.ClientID %>");
var errormsg = args.get_message();
var displaymsg = new String();
sender.deleteFileInputAt(0);
if (errormsg.search("[IO.IO_SharingViolation_File]") != -1) {
displaymsg = "File: is currently in use. Please close the file and try again.";
}
else {
displaymsg = "The file you selected is currently in use. Please close the file and try again.";
}
alert(displaymsg);
args.set_handled(true);
}
I'm programming an app that interact with dropbox by use DropNet API. I want to check if the folder is exist or not on dropbox in order to I will create one and upload file on it after that. Everything seen fine but if my folder is exist it throw exception. Like this:
if (isAccessToken)
{
byte[] bytes = File.ReadAllBytes(fileName);
try
{
string dropboxFolder = "/Public/DropboxManagement/Logs" + folder;
// I want to check if the dropboxFolder is exist here
_client.CreateFolder(dropboxFolder);
var upload = _client.UploadFile(dropboxFolder, fileName, bytes);
}
catch (DropNet.Exceptions.DropboxException ex) {
MessageBox.Show(ex.Response.Content);
}
}
I'm not familiar with dropnet, but looking at the source code, it appears you should be able to do this by using the GetMetaData() method off of your _client object. This method returns a MetaData object.
Example:
//gets contents at requested path
var metaData = _client.GetMetaData("/Public/DropboxManagement/Logs");
//without knowing how this API works, Path may be a full path and therefore need to check for "/Public/DropboxManagement/Logs" + folder
if (metaData.Contents.Any(c => c.Is_Dir && c.Path == folder)
{
//folder exists
}
string profile = "\\" + txtProfileLoad.Text + ".txt";
profile = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments) + profile;
The variable profile is receiving the correct file path, but when I run it the File.Exists comes up false every time.
if (System.IO.File.Exists(profile) == true)
{
System.IO.StreamReader profileReader;
profileReader = new System.IO.StreamReader(profile);
do
{
profileLevel = profileLevel + profileReader.ReadLine() + "\r\n";
} while (profileReader.Peek() != -1);
loadName(profileLevel);
wordBeingUsed.finalWord = loadedName;
Close();
}
else
{
MessageBox.Show("Invalid file name. Please try again.");
}
There aren't any permissions stopping it from seeing the file.
Any help with this would be appreciated. It's been driving me crazy.
Is this a pre-existing file that you are trying to read? Or is this a new file that you are hoping to create? What is the value inside txtProfileLoad.Text, issue most likely is within this property.
Run a sanity check:
var profile = "mytestfile.txt";
var myFile = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments), profile);
File.WriteAllText(myFile, "Testing file write");
if (File.Exists(myFile))
{
// Access works.
}
else
{
//Didn't work
}
If above code works, then it is most likely that the name you create from txtProfileLoad.Text is different from actual file on the drive. On the other hand, if this is a file that doesn't exist yet; then of course it would return false when you check Exists.
You can use a string variable and pass the file name to it:
string tempFile = txtProfileLoad.Text;
string profile = #"C:\temp\tempfile.txt";
Also check out if you could use the file open method instead of File.Exist.
As per MSDN:
true if the caller has the required permissions and path contains the name of an existing file; otherwise, false. This method also
returns false if path is Nothing, an invalid path, or a zero-length
string. If the caller does not have sufficient permissions to read the
specified file, no exception is thrown and the method returns false
regardless of the existence of path.
Have you tried running as an administrator? Try do "right click" on the Visual Studio icon and select "Run as Administrator", and see if you still encounter the same behaviour.