Directory.Exists(imgFolder.Path);
alternate method in win8.1 store app,
im tried search online but i do get result for file exists only not to check folder exists
In Windows 8.1 you need to do something like following.
The following method will check if files exists or not:
public async Task<bool> isFilePresent(string fileName)
{
bool fileExists = true;
Stream fileStream = null;
StorageFile file = null;
try
{
file = await ApplicationData.Current.LocalFolder.GetFileAsync(fileName);
fileStream = await file.OpenStreamForReadAsync();
fileStream.Dispose();
}
catch (FileNotFoundException)
{
// If the file dosn't exits it throws an exception, make fileExists false in this case
fileExists = false;
}
finally
{
if (fileStream != null)
{
fileStream.Dispose();
}
}
return fileExists;
}
or:
public async Task<bool> isFilePresent(string fileName)
{
var item = await ApplicationData.Current.LocalFolder.TryGetItemAsync(fileName);
return item != null;
}
From Check If File Exists in Windows Phone 8 and Win RT
Related
When attempting to download and write a file as a local user (ie, not run as admin), the following code is throwing an UnauthorizedAccessException(Access to the path is denied.). Originally, I assumed that this was due to the application attempting to write files directly to the C drive. However, I get the same error when attempting to save files to the local user's documents drive, as gotten by this:
Environment.GetFolderPath(Environment.SpecialFolder.Personal);
This seems to be a windows 10 specific issue, as the application runs fine in previous versions of windows (even writing directly to C:// as a local user, which I had thought would be blocked).
private bool DownloadFile(Stream srcStream, string dstFile)
{
bool success = false;
byte[] buffer = new byte[16384];
int byteCount;
FileStream destStream = null;
try
{
destStream = File.Create(dstFile);
while ((byteCount = srcStream.Read(buffer, 0, 16384)) != 0)
{
destStream.Write(buffer, 0, byteCount);
}
success = true;
}
catch(Exception)
{
return success;
}
finally
{
try { destStream.Close(); }
catch (Exception) { }
}
return success;
}
I have checked, and the local user account has full access to their Documents folder, so I'm stumped as to why this isn't working.
Ok I just did a unit test with your code.
The problem is
destStream = File.Create(dstFile);
This is a folder not a file!
try this:
destStream = File.Create(dstFile + "\Test.txt");
And tadaaaaa. No more exception ;)
You can not write into a folder. only inside file.
and please use using() when needed :)
Unit test:
[TestMethod]
public void TestMethod1()
{
var path = Environment.GetFold`enter code here`erPath(Environment.SpecialFolder.Personal);
// path = "C:\Users\pix\Documents"
using (var memoryStream = new MemoryStream())
{
var result = DownloadFile(memoryStream, path);
Assert.IsFalse(result);
result = DownloadFile(memoryStream, Path.Combine("FILE.txt"));
Assert.IsTrue(result);
}
}
private bool DownloadFile(Stream srcStream, string dstFile)
{
bool success = false;
byte[] buffer = new byte[16384];
int byteCount;
FileStream destStream = null;
try
{
destStream = File.Create(dstFile);
while ((byteCount = srcStream.Read(buffer, 0, 16384)) != 0)
{
destStream.Write(buffer, 0, byteCount);
}
success = true;
}
catch (Exception ex)
{
return success;
}
finally
{
try { destStream.Close(); }
catch (Exception) { }
}
return success;
}
I need to use a prepopulated database in my Xamarin.Forms application, so I searched for possible solutions.
I've found this article and tested with Android - it worked okay.
However, it uses Windows Phone 8 - that is not compatible with Windows 8.1.
So I tried to modify this Windows Phone 8 code:
public static void CopyDatabaseIfNotExists(string dbPath)
{
var storageFile = IsolatedStorageFile.GetUserStoreForApplication();
if (!storageFile.FileExists(dbPath))
{
using (var resourceStream = Application.GetResourceStream(new Uri("people.db3", UriKind.Relative)).Stream)
{
using (var fileStream = storageFile.CreateFile(dbPath))
{
byte[] readBuffer = new byte[4096];
int bytes = -1;
while ((bytes = resourceStream.Read(readBuffer, 0, readBuffer.Length)) > 0)
{
fileStream.Write(readBuffer, 0, bytes);
}
}
}
}
}
Into this code:
public static async void CopyDatabaseIfNotExists(string dbPath)
{
IStorageFolder applicationFolder = ApplicationData.Current.LocalFolder;
StorageFile existingFile = await Windows.Storage.StorageFile.GetFileFromPathAsync("prep.db");
IStorageFile storageFile = await applicationFolder.GetFileAsync(dbPath);
if (storageFile == null)
{
await existingFile.CopyAndReplaceAsync(storageFile);
However, it does not work, I can't provide a proper filepath for my existing db file (it is in the root of the project), it always gives me this error:
Value does not fall within the expected range.
How could I get a proper path to my prepopulated file?
Also, why do I need to use a stream based "copy" when I could simply copy the file itself?
The following code works for Windows Phone 8.1 and UWP:
public async void CopyDatabaseIfNotExists(string dbPath)
{
IStorageFolder applicationFolder = ApplicationData.Current.LocalFolder;
var existingFile = await Windows.ApplicationModel.Package.Current.InstalledLocation.GetFileAsync(myDBFileName);
if (!await CheckForExistingFile(myDBFileName))
await existingFile.CopyAsync(applicationFolder);
}
private async Task<bool> CheckForExistingFile(string filePath)
{
try
{
var file = await ApplicationData.Current.LocalFolder.GetFileAsync(Uri.EscapeDataString(filePath));
//no exception means file exists
return true;
}
catch (FileNotFoundException ex)
{
//find out through exception
return false;
}
}
This question already has answers here:
Wait until file is unlocked in .NET
(16 answers)
Closed 7 years ago.
private void DisplayLastTakenPhoto()
{
string mypath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.MyPictures),"RemotePhoto");
var directory = new DirectoryInfo(mypath);
var myFile = directory.EnumerateFiles()
.Where(f => f.Extension.Equals(".jpg", StringComparison.CurrentCultureIgnoreCase) || f.Extension.Equals("raw", StringComparison.CurrentCultureIgnoreCase))
.OrderByDescending(f => f.LastWriteTime)
.First();
LiveViewPicBox.Load(myFile.FullName);
}
protected virtual bool IsFileLocked(FileInfo file)
{
FileStream stream = null;
try
{
stream = file.Open(FileMode.Open, FileAccess.Read, FileShare.None);
}
catch (IOException)
{
//the file is unavailable because it is:
//still being written to
//or being processed by another thread
//or does not exist (has already been processed)
return true;
}
finally
{
if (stream != null)
stream.Close();
}
//file is not locked
return false;
}
The problem is with the line:
LiveViewPicBox.Load(myFile.FullName);
Sometimes it's working fine sometimes i'm getting exception on this line say the file is in use by another process.
So i want to use the IsFileLocked method or some other method to check untill the file is not locked.
But if i will call this method before the line
LiveViewPicBox.Load(myFile.FullName);
It will check if the file locked only once. I need somehow to use while or somet other way to check if the file is locked over and over again until it's unlocked.
And only when it's unlocked to make the line LiveViewPicBox.Load(myFile.FullName);
public static bool IsFileReady(String sFilename)
{
// If the file can be opened for exclusive access it means that the file
// is no longer locked by another process.
try
{
using (FileStream inputStream = File.Open(sFilename, FileMode.Open, FileAccess.Read, FileShare.None))
{
if (inputStream.Length > 0)
{
return true;
}
else
{
return false;
}
}
}
catch (Exception)
{
return false;
}
}
Place this in a loop and wait for it to return true.
I'm having a problem uploading a file to OneDrive from a universal app that I can't understand or figure out how to debug. I used this guide to go through the process of getting file IDs and such and it worked great until a few hours ago.
Now I can get folder and file ids, so I assume that I am still successfully connecting to OneDrive and my internet connection is still working. But when I step into the BackgroundUploadAsync the thread or whatever that was was executing before never returns. In the code below, the message "Uploading new file to OneDrive..." never disappears.
Strangely, while it is uploading I can refresh my OneDrive folder on ie and I'll never see what I'm trying to upload. But once I stop the debugger, or terminate the app on the phone, I can instantly refresh and the file will be there.
Here is the method for uploading:
public async Task UploadToOneDrive(string folderID, string localFileName)
{
try
{
StorageFile file = await ApplicationData.Current.LocalFolder.GetFileAsync(localFileName);
string fileName = "backup-" + DateTime.Now.ToString("dd-MM") + ".db";
await file.CopyAsync(ApplicationData.Current.LocalFolder, fileName, NameCollisionOption.ReplaceExisting);
file = await ApplicationData.Current.LocalFolder.GetFileAsync(fileName);
await connectClient.BackgroundUploadAsync(folderID,
fileName, file, OverwriteOption.Overwrite);
}
catch (LiveConnectException)
{
MessageDialog m = new MessageDialog("Could not connect to to OneDrive. Cloud sync will be stopped.");
m.ShowAsync();
}
catch (LiveAuthException)
{
MessageDialog m = new MessageDialog("Error authenticating OneDrive service. Please try cloud sync again later.");
m.ShowAsync();
}
catch (Exception ex)
{
MessageDialog m = new MessageDialog("Unknown exception occurred.\n\nError:{0}", ex.Message);
m.ShowAsync();
}
}
And here is the sync process
public async Task sync()
{
var sb = StatusBar.GetForCurrentView();
sb.ProgressIndicator.Text = "Syncing with OneDrive...";
await sb.ProgressIndicator.ShowAsync();
string cloudFolderID = await syncManager.CreateOrGetOneDriveFolderID("GlucoseCalculator", "Documents/");
string cloudFileID = await syncManager.GetFileID(DataManager.sqlFileName, "Documents/GlucoseCalculator/");
try
{
if (cloudFileID != null)
{
if (!(await dbManager.DoesFileExist(DataManager.sqlFileName)))
{
sb.ProgressIndicator.Text = "Downloading file from OneDrive...";
await syncManager.DownloadFromOneDrive(cloudFileID, DataManager.sqlFileName);
goto BREAK;
}
DateTime cloudLastEditDateTime = DateTime.Parse(await syncManager.GetFileProperty(cloudFileID, "updated_time"));
DateTime localLastEditDateTime = ApplicationData.Current.LocalFolder.GetFileAsync(DataManager.sqlFileName).GetResults().GetBasicPropertiesAsync().GetResults().DateModified.DateTime;
if (cloudLastEditDateTime > localLastEditDateTime)
{
sb.ProgressIndicator.Text = "Downloading file from OneDrive...";
await syncManager.DownloadFromOneDrive(cloudFileID, DataManager.sqlFileName);
}
else if (cloudLastEditDateTime < localLastEditDateTime)
{
sb.ProgressIndicator.Text = "Uploading file to OneDrive...";
await syncManager.UploadToOneDrive(cloudFolderID, DataManager.sqlFileName);
}
}
else if (cloudFileID == null)
{
sb.ProgressIndicator.Text = "Uploading new file to OneDrive...";
await syncManager.UploadToOneDrive(cloudFolderID, DataManager.sqlFileName);
}
}
catch (Exception)
{
sb.ProgressIndicator.Text = "Cloud synchronization failed.";
sb.ProgressIndicator.HideAsync();
return;
}
sb.ProgressIndicator.Text = "Synchronization complete!";
BREAK:;
await sb.ProgressIndicator.HideAsync();
}
Most likely, you are creating some object that implements IDisposible, but it is not in a using block. Maybe the StorageFile.
What I want
get a xml file from the AppData.Local, and serialize it to a list
What I code
The Error Part:
List<myTask> AllTaskList = await objectStorageHelper.LoadAsync();
myTask is a simple class:
public class myTask
{
public string myTitle { get; set; }
public string myDuetime { get; set; }
}
objectStorageHelper is a HelpClass from CodePlex, the LoadAsync part is below:
public async Task<T> LoadAsync()
{
try
{
StorageFile file = null;
StorageFolder folder = GetFolder(storageType);
file = await folder.GetFileAsync(FileName());
//file = await folder.CreateFileAsync("BetterTask.xml", CreationCollisionOption.OpenIfExists);
IRandomAccessStream readStream = await file.OpenAsync(FileAccessMode.Read);
Stream inStream = Task.Run(() => readStream.AsStreamForRead()).Result;
return (T)serializer.Deserialize(inStream);
}
catch (FileNotFoundException)
{
//file not existing is perfectly valid so simply return the default
return default(T);
//Interesting thread here: How to detect if a file exists (http://social.msdn.microsoft.com/Forums/en-US/winappswithcsharp/thread/1eb71a80-c59c-4146-aeb6-fefd69f4b4bb)
//throw;
}
catch (Exception)
{
//Unable to load contents of file
throw;
}
}
What is the Error
An exception of type 'System.UnauthorizedAccessException' occurred in mscorlib.dll but was not handled in user code
Additional information: Access Denied。 (Exception from HRESULT:0x80070005 (E_ACCESSDENIED))
If there is a handler for this exception, the program may be safely continued.
--
Why does this happen？
I can use this help class to successfully write to a file.
But Why don't I have the permission to read the file?
How to solve it?
change
StorageFolder folder = GetFolder(storageType);
to
StorageFolder folder = ApplicationData.Current.LocalFolder
if this works then the issue is with your folder permissions.
change
Stream inStream = Task.Run(() => readStream.AsStreamForRead()).Result;
return (T)serializer.Deserialize(inStream);
to
using (Stream inStream = Task.Run(() => readStream.AsStreamForRead()).Result)
{
return (T)this.xmlSerializer.Deserialize(inStream);
}
or
inStream.Flush();
inStream.Dispose();
and the same to the SaveAsync()