WinRT Storage APIs
The Windows Runtime (WinRT) provides a comprehensive set of APIs for interacting with storage in Windows applications. These APIs enable you to manage files, folders, and local application data in a secure and efficient manner.
Core Concepts
Understanding the fundamental concepts behind WinRT storage is crucial for effective usage:
- File Access: Programmatically read, write, create, and delete files.
- Folder Management: Browse, create, and manage directories and subdirectories.
- Storage Locations: Access well-known folders like local app data, documents, pictures, and removable storage.
- Asynchronous Operations: Most storage operations are asynchronous to ensure a responsive user interface.
Key Classes and Interfaces
Here are some of the most important classes and interfaces you'll encounter when working with WinRT storage:
Windows.Storage.StorageFolder
Represents a folder in the file system. You can use this class to:
- Get a reference to well-known folders (e.g.,
ApplicationData.Current.LocalFolder
). - Create new folders within an existing folder.
- Query for files and subfolders within a folder.
- Delete folders.
Example:
// Get the local app data folder
var localFolder = Windows.Storage.ApplicationData.Current.LocalFolder;
// Create a new folder
await localFolder.CreateFolderAsync("MyAppData");
View Class Reference
Windows.Storage.StorageFile
Represents a file in the file system. Key operations include:
- Opening existing files for reading or writing.
- Creating new files.
- Copying, moving, and renaming files.
- Getting file properties like size, date created, and content type.
Example:
// Create a new file
var newFile = await localFolder.CreateFileAsync("settings.txt");
// Write content to the file
await Windows.Storage.FileIO.WriteTextAsync(newFile, "Setting1=Value1\nSetting2=Value2");
View Class Reference
Windows.Storage.FileIO
A static class providing utility methods for reading and writing file content efficiently. It supports various data formats:
ReadTextAsync
WriteTextAsync
ReadBufferAsync
WriteBufferAsync
ReadLinesAsync
Windows.Storage.KnownFolders
Provides access to well-known system folders that users typically interact with, such as:
KnownFolders.DocumentsLibrary
KnownFolders.PicturesLibrary
KnownFolders.MusicLibrary
KnownFolders.VideosLibrary
KnownFolders.RemovableDevices
Permissions: Accessing these libraries often requires specific capabilities declared in your app's manifest.
View Class ReferenceCommon Scenarios
Explore common tasks and how to implement them using WinRT Storage APIs:
- Managing Application Data
- Accessing User Libraries (Documents, Pictures, etc.)
- Handling File Pickers
- Implementing File Synchronization
Best Practices
- Always use asynchronous methods for I/O operations to keep your UI responsive.
- Handle exceptions gracefully, especially for file access errors.
- Request necessary capabilities in your app manifest for accessing certain storage locations.
- Consider using
StorageApplicationPermissions
for more granular control over app data access.