public static Task <bool> IsKnownFolderFileExistsAsync(
KnownFolderId knownFolderId,
string fileName)
{
StorageFolder workingFolder = StorageFileHelper.GetFolderFromKnownFolderId(knownFolderId);
return(workingFolder.IsFileExistsAsync(fileName));
}
/// <summary>
/// Gets a stream to a specified file from the application local cache folder.
/// </summary>
/// <param name="knownFolderId">The well known folder ID to use</param>
/// <param name="fileName">Relative name of the file to open. Can contains subfolders.</param>
/// <param name="accessMode">File access mode. Default is read.</param>
/// <returns>The file stream</returns>
public static Task <IRandomAccessStream> GetKnowFoldersFileStreamAsync(
KnownFolderId knownFolderId,
string fileName,
FileAccessMode accessMode = FileAccessMode.Read)
{
StorageFolder workingFolder = StorageFileHelper.GetFolderFromKnownFolderId(knownFolderId);
return(GetFileStreamAsync(fileName, accessMode, workingFolder));
}
/// <summary>
/// Saves an object inside a file.
/// There is no limitation to use this method (refers to <see cref="Save{T}(string, T)"/> method for simple objects).
/// </summary>
/// <typeparam name="T">Type of object saved</typeparam>
/// <param name="filePath">Path to the file that will contain the object</param>
/// <param name="value">Object to save</param>
/// <returns>The <see cref="StorageFile"/> where the object was saved</returns>
public Task <StorageFile> SaveFileAsync <T>(string filePath, T value)
{
return(StorageFileHelper.WriteTextToFileAsync(Folder, JsonConvert.SerializeObject(value), filePath, CreationCollisionOption.ReplaceExisting));
}
/// <summary>
/// Retrieves an object from a file.
/// </summary>
/// <typeparam name="T">Type of object retrieved</typeparam>
/// <param name="filePath">Path to the file that contains the object</param>
/// <param name="default">Default value of the object</param>
/// <returns>Waiting task until completion with the object in the file</returns>
public async Task <T> ReadFileAsync <T>(string filePath, T @default = default(T))
{
string value = await StorageFileHelper.ReadTextFromFileAsync(Folder, filePath);
return((value != null) ? JsonConvert.DeserializeObject <T>(value) : @default);
}
/// <summary>
/// Saves an object inside a file.
/// There is no limitation to use this method (refers to <see cref="Save{T}(string, T)"/> method for simple objects).
/// </summary>
/// <typeparam name="T">Type of object saved</typeparam>
/// <param name="filePath">Path to the file that will contain the object</param>
/// <param name="value">Object to save</param>
/// <returns>The <see cref="StorageFile"/> where the object was saved</returns>
public Task <StorageFile> SaveFileAsync <T>(string filePath, T value)
{
return(StorageFileHelper.WriteTextToFileAsync(Folder, serializer.Serialize(value)?.ToString(), filePath, CreationCollisionOption.ReplaceExisting));
}
private async Task <T?> ReadFileAsync <T>(StorageFolder folder, string filePath, T? @default = default)
{
string value = await StorageFileHelper.ReadTextFromFileAsync(folder, filePath);
return((value != null) ? this.Serializer.Deserialize <T>(value) : @default);
}
private async Task <StorageFile> CreateFileAsync <T>(StorageFolder folder, string filePath, T value)
{
return(await StorageFileHelper.WriteTextToFileAsync(folder, Serializer.Serialize(value)?.ToString(), NormalizePath(filePath), CreationCollisionOption.ReplaceExisting));
}