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StorageFileHelper

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The StorageFileHelper is a static utility class that provides functions to help with reading and writing of text and bytes to the disk. These functions are all wrapped into Async tasks.

Syntax

// NOTE This must be used from an async function
string myText = "Great information that the users wants to keep";
StorageFolder localFolder = Windows.Storage.ApplicationData.Current.LocalFolder;

// Save some text to a file named appFilename.txt (in the local cache folder)
var storageFile = await StorageFileHelper.WriteTextToLocalCacheFileAsync(myText, "appFilename.txt");

// Load some text from a file named appFilename.txt in the local cache folder 
string loadedText = await StorageFileHelper.ReadTextFromLocalCacheFileAsync("appFilename.txt");

// Save some text to a file named appFilename.txt (in the local folder)
storageFile = await StorageFileHelper.WriteTextToLocalFileAsync(myText, "appFilename.txt");

// Load some text from a file named appFilename.txt in the local folder 
loadedText = await StorageFileHelper.ReadTextFromLocalFileAsync("appFilename.txt");

// Check if a file exists in a specific folder
bool exists = await localFolder.FileExistsAsync("appFilename.txt");

// Check if a file exists in a specific folder or in one of its subfolders
bool exists = await localFolder.FileExistsAsync("appFilename.txt", true);

// Check if a file name is valid or not
bool isFileNameValid = StorageFileHelper.IsFileNameValid("appFilename.txt");

// Check if a file path is valid or not
bool isFilePathValid = StorageFileHelper.IsFilePathValid("folder/appFilename.txt");

' NOTE This must be used from an async function
Dim myText As String = "Great information that the users wants to keep"
Dim localFolder As StorageFolder = Windows.Storage.ApplicationData.Current.LocalFolder

' Save some text to a file named appFilename.txt (in the local cache folder)
Dim storageFile = Await StorageFileHelper.WriteTextToLocalCacheFileAsync(myText, "appFilename.txt")

' Load some text from a file named appFilename.txt in the local cache folder 
Dim loadedText As String = Await StorageFileHelper.ReadTextFromLocalCacheFileAsync("appFilename.txt")

' Save some text to a file named appFilename.txt (in the local folder)
storageFile = Await StorageFileHelper.WriteTextToLocalFileAsync(myText, "appFilename.txt")

' Load some text from a file named appFilename.txt in the local folder 
loadedText = Await StorageFileHelper.ReadTextFromLocalFileAsync("appFilename.txt")

' Check if a file exists in a specific folder
Dim exists As Boolean = Await localFolder.FileExistsAsync("appFilename.txt")

' Check if a file exists in a specific folder or in one of its subfolders
Dim exists As Boolean = Await localFolder.FileExistsAsync("appFilename.txt", True)

' Check if a file name is valid or not
Dim isFileNameValid As Boolean = StorageFileHelper.IsFileNameValid("appFilename.txt")

' Check if a file path is valid or not
Dim isFilePathValid As Boolean = StorageFileHelper.IsFilePathValid("folder/appFilename.txt")

Methods

Methods Return Type Description
FileExistsAsync(StorageFolder, String, Boolean) Task<bool> Gets a value indicating whether a file exists in the current folder
IsFileNameValid(String) bool Gets a value indicating whether a filename is correct or not using the Storage feature
IsFilePathValid(String) bool Gets a value indicating whether a file path is correct or not using the Storage feature
ReadBytesAsync(StorageFile) Task<byte[]> Gets an array of bytes from a StorageFile
ReadBytesFromFileAsync(StorageFolder, String) Task<byte[]> Gets an array of bytes from a StorageFile located in the given StorageFolder
ReadBytesFromKnownFoldersFileAsync(KnownFolderId, String) Task<byte[]> Gets an array of bytes from a StorageFile located in a well known folder
ReadBytesFromLocalCacheFileAsync(String) Task<byte[]> Gets an array of bytes from a StorageFile located in the application local cache folder
ReadBytesFromLocalFileAsync(String) Task<byte[]> Gets an array of bytes from a StorageFile located in the application local folder
ReadBytesFromPackagedFileAsync(String) Task<byte[]> Gets an array of bytes from a StorageFile located in the application installation folder
ReadTextFromFileAsync(StorageFolder, String) Task<string> Gets a string value from a StorageFile located in the given StorageFolder
ReadTextFromKnownFoldersFileAsync(KnownFolderId, String) Task<string> Gets a string value from a StorageFile located in a well known folder
ReadTextFromLocalCacheFileAsync(String) Task<string> Gets a string value from a StorageFile located in the application local cache folder
ReadTextFromLocalFileAsync(String) Task<string> Gets a string value from a StorageFile located in the application local folder
ReadTextFromPackagedFileAsync(String) Task<string> Gets a string value from a StorageFile located in the application installation folder
WriteBytesToFileAsync(StorageFolder, Byte[], String, CreationCollisionOption) Task<StorageFile> Saves an array of bytes to a StorageFile in the given StorageFolder
WriteBytesToKnownFolderFileAsync(KnownFolderId, Byte[], String, CreationCollisionOption) Task<StorageFile> Saves an array of bytes to a StorageFile to well known folder
WriteBytesToLocalCacheFileAsync(Byte[], String, CreationCollisionOption) Task<StorageFile> Saves an array of bytes to a StorageFile to application local cache folder
WriteBytesToLocalFileAsync(Byte[], String, CreationCollisionOption) Task<StorageFile> Saves an array of bytes to a StorageFile to application local folder
WriteTextToFileAsync(StorageFolder, String, String, CreationCollisionOption) Task<StorageFile> Saves a string value to a StorageFile in the given StorageFolder
WriteTextToKnownFolderFileAsync(KnownFolderId, String, String, CreationCollisionOption) Task<StorageFile> Saves a string value to a Windows.Storage.StorageFile in well known folder
WriteTextToLocalCacheFileAsync(String, String, CreationCollisionOption) Task<StorageFile> Saves a string value to a Windows.Storage.StorageFile in application local cache folder
WriteTextToLocalFileAsync(String, String, CreationCollisionOption) Task<StorageFile> Saves a string value to a Windows.Storage.StorageFile in application local folder

Sample Code

You can find more examples in our unit tests

Requirements

Device family Universal, 10.0.16299.0 or higher
Namespace Microsoft.Toolkit.Uwp
NuGet package Microsoft.Toolkit.Uwp

API