So im making a windows store app that you select a file with one button, via file picker, then with another button it processes that file but im having trouble getting the selected file to processing method.
Since the Picker sets one of my text blocks to the path of the file to be displayed for the user i've tried using:
StorageFile file = await StorageFile.GetFileFromPathAsync(fullFilePath.Text);
But due to Windows RT limitations I just get access it denied from most locations
Any other suggestions on what to try?
First button click:
private async Task getFile()
{
FileOpenPicker openPicker = new FileOpenPicker();
openPicker.ViewMode = PickerViewMode.List;
openPicker.SuggestedStartLocation = PickerLocationId.DocumentsLibrary;
openPicker.FileTypeFilter.Add(".txt");
StorageFile file = await openPicker.PickSingleFileAsync();
if (file != null)
{
fullFilePath.Text = file.Path;
}
else
{
updateStatus("File Selection cancelled.");
}
}
Second button start this but needs to use the file from above
private async Task processFile()
{
...
string content = await FileIO.ReadTextAsync(file);
...
}
Make the StorageFile a field in your class:
class MyClass
{
StorageFile m_pickedFile;
async Task GetFile()
{
// Setup the picker...
m_pickedFile = await openPicker.PickSingleFileAsync();
// Show the path to the user...
}
async Task ProcessFile()
{
if (m_pickedFile != null)
{
// now use m_pickedFile...
}
}
}
Related
I'm trying to save my text file in UWP, but It always saving to different file. By the way I'm using MVVM architecture.
My Code
FileSavePicker savePicker = new FileSavePicker();
savePicker.SuggestedFileName = "New Text Document";
savePicker.SuggestedStartLocation = PickerLocationId.Desktop;
savePicker.FileTypeChoices.Add("Text Document", new List<string>() { ".txt" });
savePicker.DefaultFileExtension = ".txt";
StorageFile storageFile = await savePicker.PickSaveFileAsync();
if(storageFile != null)
{
CachedFileManager.DeferUpdates(storageFile);
await FileIO.WriteTextAsync(storageFile, Document.Text);
FileUpdateStatus updateStatus = await CachedFileManager.CompleteUpdatesAsync(storageFile);
Document.FileName = savePicker.SuggestedFileName;
Document.IsSaved = true;
}
My code is always saving texts on different file. I'm trying to save my text to same file.
In UWP there is a feature called FutureAccessList. It can be used to save the token of the file, opened with the FilePicker. When you now want to save it again you can retrive the StorageFile by the token and write to it.
Add a FileToken property to your Document class:
public string FileToken { get; set; }
Now when you pick your file you add the file to the FutureAccessList:
...
StorageFile storageFile = await savePicker.PickSaveFileAsync();
if (storageFile != null)
{
CachedFileManager.DeferUpdates(storageFile);
await FileIO.WriteTextAsync(storageFile, Document.Text);
FileUpdateStatus updateStatus = await CachedFileManager.CompleteUpdatesAsync(storageFile);
Document.FileName = savePicker.SuggestedFileName;
Document.IsSaved = true;
//Add the file to the FutureAccessList to get it back later
Document.FileToken = StorageApplicationPermissions.FutureAccessList.Add(storageFile);
}
To retrive the file and save it again:
public async void SaveFile()
{
//Get the file back from the FutureAccessList by its token and write to it
StorageFile file = await StorageApplicationPermissions.FutureAccessList.GetFileAsync(Document.FileToken);
await FileIO.WriteTextAsync(file, Document.Text);
}
Now when you e.g. save your Document class to Json and retrive it after the app restarts you can still use the FileToken to write to the file. There is no need to let the user pick it again using the SaveFilePicker.
When the code above is to complicated or there is no need for this (I don't know what you need this for), you can put a StorageFile propertie directly to your Document class and put the file, that the SaveFilePicker returned in it. But this won't work when restarting the app. The user would always have to pick the file again.
I read some topic about file permission.
Someone said "App can access directories and files which the user manually selected with the FileOpenPicker or FolderPicker"
My codes are like as below:
public async void CsvParse()
{
var picker = new Windows.Storage.Pickers.FileOpenPicker();
picker.FileTypeFilter.Add(".csv");
Windows.Storage.StorageFile file = await picker.PickSingleFileAsync();
if (file != null)
{
string[] lines = File.ReadAllLines(file.Path);//this is where app stops working and gives error message.
}
}
Even when I choose file with FilePicker, it still gives me error. But when I choose file from appx folder, it works fine.
Is there a way to access other locations than app's folder?
try it this way:
public async void CsvParse()
{
var picker = new Windows.Storage.Pickers.FileOpenPicker();
picker.FileTypeFilter.Add(".csv");
Windows.Storage.StorageFile file = await picker.PickSingleFileAsync();
if (file != null)
{
IList<string> lines = await FileIO.ReadLinesAsync(file);//this is where app stops working and gives error message.
}
}
the StorageFile is the way you get access to a file. File.ReadAllLines(file.Path) you are passing a Filename, not the StorageFile but just the filepath is not enough for getting access
I am trying to play a sound with audio graph and it is failing on creating a file output node from a storage file. I have checked and the storage file is not null; The error I am getting is just unknown error and is of no help
Any ideas?
private async void HandlePlayCommand()
{
if (_audioGraph == null)
{
var settings = new AudioGraphSettings(AudioRenderCategory.Media);
var createResults = await AudioGraph.CreateAsync(settings);
if (createResults.Status != AudioGraphCreationStatus.Success) return;
_audioGraph = createResults.Graph;
var deviceResult = await _audioGraph.CreateDeviceOutputNodeAsync();
if(deviceResult.Status != AudioDeviceNodeCreationStatus.Success) return;
var outputNode = deviceResult.DeviceOutputNode;
StorageFile file = await GetStorageFiles();
var fileResult = await _audioGraph.CreateFileInputNodeAsync(file);
if (fileResult.Status != AudioFileNodeCreationStatus.Success) return;
var fileInputNode = fileResult.FileInputNode;
fileInputNode.AddOutgoingConnection(outputNode);
_audioGraph.Start();
}
}
private async Task<StorageFile> GetStorageFiles()
{
string CountriesFile = #"Assets\909_1.aif";
StorageFolder InstallationFolder = Windows.ApplicationModel.Package.Current.InstalledLocation;
StorageFile file = await InstallationFolder.GetFileAsync(CountriesFile);
return file;
}
By testing on my side, I'm afraid the .aif format currently is not supported by AudioGraph.CreateFileInputNodeAsync method. The formats sure to be supported that are .mp3,.wav,.wna,.m4a and so on. So the solution maybe change the audio files to other formats.
More details please reference the audio official sample.
public static async Task Store(ObservableCollection<Product> list)
{
Uri path = new Uri("ms-appx:///ListCollection.json");
var store = await StorageFile.GetFileFromApplicationUriAsync(path);
var stream = File.OpenWrite(store.Path);
var serialize = new DataContractJsonSerializer(typeof(ObservableCollection<Product>));
serialize.WriteObject(stream, list);
}
Ok this is the piece of code that I used to serialize a collection , works very well , no problem with it , but what I want and tried and no success. I created a JSON file in my project. I want to store and stream data to that file. I tried some methods but no success , how do I open a stream to a file that is currently in my project?
EDITED : Commented the code that was working and wrote what I intend to do. Thanks for support.
When I get to this line
var stream = File.OpenWrite(store.Path); it says that is inaccesible.
What I intend to do is serialize some data to a file called ListCollection.json that is emtpy , that file is project file. It might be the stream or it might be the file that gives me that error. No idea.
My guess is that your project file is located in the installation directory of your application and as far as I know you can't just write to that directory.
You would have to put a deployment action in your solution that writes the desired project file to the application data directory. There you should be able to write it.
I looked through some of the documentation and came accross this:
MSDN
The app's install directory is a read-only location.
I found a Link which makes use of a little hack or so it seems.
I am not sure if this will work if the application is deployed etc.
but you can try this to write the file.
I am not sure if you need a stream or not but feel free to comment:
private void Button_Click(object sender, RoutedEventArgs e)
{
ObservableCollection<string> list = new ObservableCollection<string>();
list.Add("Hallo");
list.Add("Welt");
Task t = Store(list);
}
public static async Task Store(ObservableCollection<string> list)
{
StorageFile file = await GetStorageFileFromApplicationUriAsync();
if (file == null)
{
file = await GetStorageFileFromFileAsync();
}
if (file != null)
{
await file.DeleteAsync();
await CreateFileInInstallationLocation(list);
}
}
private static async Task<StorageFile> GetStorageFileFromFileAsync()
{
StorageFile file = null;
if (file == null)
{
try
{
StorageFolder folder = Windows.ApplicationModel.Package.Current.InstalledLocation;
file = await folder.GetFileAsync("ListCollection.json");
}
catch
{ }
}
return file;
}
private static async Task<StorageFile> GetStorageFileFromApplicationUriAsync()
{
StorageFile file = null;
try
{
Uri path = new Uri("ms-appx:///ListCollection.json");
file = await StorageFile.GetFileFromApplicationUriAsync(path);
}
catch
{ }
return file;
}
private static async Task CreateFileInInstallationLocation(ObservableCollection<string> list)
{
var pkg = Windows.ApplicationModel.Package.Current;
var installedLocationFolder = pkg.InstalledLocation;
try
{
var file = await installedLocationFolder.CreateFileAsync("ListCollection.json", Windows.Storage.CreationCollisionOption.GenerateUniqueName);
var filePath = file.Path;
DataContractJsonSerializer serialize = new DataContractJsonSerializer(typeof(ObservableCollection<String>));
using (Stream stream = await file.OpenStreamForWriteAsync())
{
serialize.WriteObject(stream, list);
stream.Flush();
}
}
catch (Exception ex)
{
var msg = ex.Message;
}
}
What this basically does is:
Find the file
Delete the file
Create a new file
Write your JSON to the file
I am really not an expert on this matter and it even to me seems pretty hacky but it apparently does the job.
If you can avoid writing to the install directory do it and use the method Frank J proposed
I'm making a Windows 8 Metro Style test application using XML files. I have the reading of the file and nodes working including editing and deleting them.
The problem I'm facing now and can't figure out how to complete is the adding of a node.
Below here is the code I'm using for reading and saving.
private static async System.Threading.Tasks.Task<XmlDocument> LoadXML()
{
StorageFolder storageFolder = ApplicationData.Current.RoamingFolder;
StorageFile storageFile = await storageFolder.GetFileAsync("Settings.xml");
var XmlFile = await XmlDocument.LoadFromFileAsync(storageFile);
return XmlFile;
}
private static async System.Threading.Tasks.Task SaveXML(XmlDocument XmlFile)
{
StorageFolder storageFolder = ApplicationData.Current.RoamingFolder;
StorageFile storageFile = await storageFolder.GetFileAsync("Settings.xml");
await XmlFile.SaveToFileAsync(storageFile);
MessageDialog Message = new MessageDialog("Data is saved/removed!", "Notification");
await Message.ShowAsync();
}
This part below is of an event which refers to the two above. In this part of the code do I need to add a new node based on information from a textbox.
private async void btnSaveproject_Click(object sender, RoutedEventArgs e)
{
var XmlFile = await LoadXML();
await SaveXML(XmlFile);
}
For those who wonder how I have done the removing and editing will I also add these part of the code right below here.
// Removing
IXmlNode Node = XmlFile.SelectSingleNode("XML").SelectSingleNode("List").SelectSingleNode(lvList.SelectedItem.ToString());
XmlFile.SelectSingleNode("XML").SelectSingleNode("List").RemoveChild(Node);
//Saving
XmlFile.SelectSingleNode("XML").SelectSingleNode("Colors").SelectSingleNode("ColorR").InnerText = tbxColorR.Text;