WinRT API Documentation

Windows Runtime (WinRT) APIs

Windows Runtime (WinRT) is a set of modern APIs that allow developers to build Windows apps using a variety of programming languages. It provides access to low-level operating system features and high-level application functionalities in a consistent and efficient manner.

Core Concepts

Understanding the core concepts of WinRT is crucial for effective development. This section provides an overview of key principles:

Projections: How WinRT types are represented in different language ecosystems.
Asynchronous Operations: Using Windows Runtime asynchronous patterns for non-blocking operations.
Event Handling: Subscribing to and handling events raised by WinRT APIs.
Activation: How WinRT objects are created and activated.
Runtime Classes: The fundamental building blocks of WinRT APIs.

Key Namespaces and Classes

Explore the essential namespaces and classes that form the foundation of WinRT development:

Windows.Foundation

This namespace contains fundamental types and interfaces used across the WinRT ecosystem.

IAsyncOperation: Represents an asynchronous operation that returns a result.
AsyncOperationCompletedHandler: A delegate for completing asynchronous operations.
DateTime: Represents a point in time.
TimeSpan: Represents a duration.

Windows.Storage

Provides APIs for interacting with files and folders.

StorageFile: Represents a file in the file system.
StorageFolder: Represents a folder in the file system.
FileAccessMode: Enumeration for specifying file access permissions.
CreationCollisionOption: Specifies how to handle collisions during file creation.

Windows.Networking.Sockets

Enables network communication.

StreamSocket: Represents a TCP stream socket.
DatagramSocket: Represents a UDP datagram socket.
SocketErrorStatus: Enumerates the possible network socket errors.

Example: Reading a File Asynchronously

This example demonstrates how to use WinRT APIs to read the content of a text file asynchronously.

C++/WinRT Example


#include <winrt/Windows.Foundation.h>
#include <winrt/Windows.Storage.h>
#include <iostream>

using namespace winrt;
using namespace Windows::Foundation;
using namespace Windows::Storage;

int main() {
    init_apartment();

    async_runtime().run_until_complete(async () {
        try {
            StorageFile file = co_await StorageFile::GetFileFromApplicationUriAsync(
                Uri(L"ms-appx:///Assets/sample.txt")
            );
            Streams::Buffer buffer = co_await FileIO::ReadBufferAsync(file);
            std::string content = buffer.AsString(); // Simplified for example
            std::wcout << L"File content: " << content.c_str() << std::endl;
        } catch (const hresult_error& e) {
            std::wcerr << L"Error: " << e.message() << std::endl;
        }
    });

    return 0;
}

C# Example


using Windows.Storage;
using System;
using System.Threading.Tasks;

public sealed partial class MainPage : Page
{
    public async void ReadFileContent()
    {
        try
        {
            StorageFile file = await StorageFile.GetFileFromApplicationUriAsync(new Uri("ms-appx:///Assets/sample.txt"));
            string content = await FileIO.ReadTextAsync(file);
            System.Diagnostics.Debug.WriteLine($"File content: {content}");
        }
        catch (Exception ex)
        {
            System.Diagnostics.Debug.WriteLine($"Error: {ex.Message}");
        }
    }
}

Common Patterns

CreateFileAsync method in StorageFolder.
WriteTextAsync and ReadTextAsync in FileIO.
GetAwaiter() for converting async operations to awaitable tasks.

MSDN Documentation