UpdateService — Auto-Update and Download API Reference

UpdateService provides self-update capabilities by querying the GitHub Releases API for the latest published release, comparing it against the running assembly version, and streaming the installer to %TEMP% before launching it via the Windows shell. The service is designed to be called once at startup for a background check and optionally on-demand for user-initiated downloads.

The GitHub unauthenticated API rate limit is 60 requests per hour per IP address. CheckAsync makes one request per call. No authentication token is sent — keep polling intervals reasonable (e.g. once per application launch).

Static property

`CurrentVersion`

public static string CurrentVersion { get; }

The version string of the running assembly, resolved once at class initialization. Resolution priority:

AssemblyInformationalVersionAttribute — build metadata suffix (+abc123) is stripped and the result is validated as a System.Version.
Assembly.GetName().Version — formatted as Major.Minor.Build (Build clamped to ≥ 0).
Falls back to "0.0.0" if no version information is available.

The leading v/V prefix is always stripped so version strings are plain semver (e.g. "1.2.3").

Properties

`IsUpdateAvailable`

public bool IsUpdateAvailable { get; private set; }

Set to true by CheckAsync when the latest GitHub release version is semantically newer than CurrentVersion. Starts as false and is never reset to false within a session.

`LatestVersion`

public string LatestVersion { get; private set; }

The version tag of the latest release found by CheckAsync, with the leading v/V stripped (e.g. "1.4.0"). Initialized to CurrentVersion before any check is performed.

`InstallerDownloadUrl`

public string? InstallerDownloadUrl { get; }

The direct download URL for the release asset selected for the current machine. null until CheckAsync finds a newer release with a matching asset. Asset selection order:

An .exe asset whose name contains x64 (case-insensitive)
An .exe asset whose name contains arm64
Any .exe asset

Events

`StateChanged`

public event Action? StateChanged;

Fired by CheckAsync immediately after IsUpdateAvailable is set to true. Raised on the calling thread (the await continuation thread — typically a thread pool thread). Marshal to the UI thread if updating UI elements.

updateService.StateChanged += () =>
{
    _dispatcherQueue.TryEnqueue(() =>
    {
        UpdateBadge.Visibility = Visibility.Visible;
    });
};

Types

`DownloadProgress`

public sealed record DownloadProgress(
    string Message,
    int? Percentage = null,
    bool IsIndeterminate = false);

Progress reporting type passed to the IProgress<DownloadProgress> callback of DownloadAndInstallAsync.

Message

string

Human-readable status description suitable for display in a progress dialog (e.g. "Downloading installer...", "Download complete. Launching installer...").

Percentage

int?

Download completion percentage from 0 to 100. null when the server does not provide a Content-Length header.

IsIndeterminate

bool

true during phases where progress cannot be quantified (connection setup, size-unknown download). Bind to an indeterminate ProgressBar or ProgressRing when this is true.

Methods

`CheckAsync(CancellationToken)`

Asynchronously queries the GitHub Releases API and sets IsUpdateAvailable, LatestVersion, and InstallerDownloadUrl if a newer version is found. Any network or parsing failure is caught and written to Debug.WriteLine — the method never throws.

public async Task CheckAsync(CancellationToken ct = default)

CancellationToken

default:"default"

Optional cancellation token. Cancels the HTTP request and deserialization.

API endpoint: https://api.github.com/repos/sgm1018/BetterWinTab/releases/latest HTTP client configuration:

Timeout: 15 seconds
User-Agent: BetterWinTab-Updater/{CurrentVersion}
Accept: application/vnd.github+json
X-GitHub-Api-Version: 2022-11-28

Version comparison: Uses System.Version parsing for semantic comparison (r > l). Falls back to case-insensitive string equality when either string cannot be parsed as a Version. Example:

await updateService.CheckAsync();

if (updateService.IsUpdateAvailable)
{
    Console.WriteLine($"Update available: {updateService.LatestVersion}");
}

`DownloadAndInstallAsync(IProgress<DownloadProgress>?, CancellationToken)`

Streams the installer binary from InstallerDownloadUrl to %TEMP%\{filename}, then launches it via Process.Start with UseShellExecute = true. Returns false immediately if no installer URL is available.

public async Task<bool> DownloadAndInstallAsync(
    IProgress<DownloadProgress>? progress = null,
    CancellationToken ct = default)

progress

IProgress<DownloadProgress>?

default:"null"

Optional progress sink. Receives DownloadProgress records throughout the download lifecycle. Pass an IProgress<T> implementation backed by a UI control to show a progress bar or dialog. When null, the download proceeds silently.

CancellationToken

default:"default"

Optional cancellation token. Cancels the in-progress stream read. The partial file on disk is not cleaned up automatically on cancellation.

return

bool

true if the download completed and the installer was launched. false if InstallerDownloadUrl is null or empty (i.e. CheckAsync was not called or found no update).

The download uses a separate HttpClient with an infinite timeout (Timeout.InfiniteTimeSpan) and an 81,920-byte (80 KiB) streaming buffer. The filename is derived from the URL path — if the path segment is empty, it defaults to BetterWinTab-Setup-{LatestVersion}-x64.exe. Progress lifecycle:

Phase	`Message`	`Percentage`	`IsIndeterminate`
Setup	`"Preparing installer download..."`	`0`	`true`
Connecting	`"Connecting to the release server..."`	`0`	`true`
Downloading (known size)	`"Downloading installer..."`	`0–100`	`false`
Downloading (unknown size)	`"Downloading installer (size unknown)..."`	`null`	`true`
Complete	`"Download complete. Launching installer..."`	`100`	`false`
Launched	`"Installer opened. Follow the installation steps."`	`100`	`false`

Example with progress:

var progress = new Progress<DownloadProgress>(p =>
{
    _dispatcherQueue.TryEnqueue(() =>
    {
        StatusText.Text = p.Message;
        if (p.Percentage.HasValue)
            DownloadBar.Value = p.Percentage.Value;
        DownloadBar.IsIndeterminate = p.IsIndeterminate;
    });
});

bool launched = await updateService.DownloadAndInstallAsync(progress);

Models

Services

UpdateService — Auto-Update and Download API Reference

Static property

`CurrentVersion`

Properties

`IsUpdateAvailable`

`LatestVersion`

`InstallerDownloadUrl`

Events

`StateChanged`

Types

`DownloadProgress`

Methods

`CheckAsync(CancellationToken)`

`DownloadAndInstallAsync(IProgress<DownloadProgress>?, CancellationToken)`

Build docs developers (and LLMs) love

Models

Services

Documentation Index

​Static property

​CurrentVersion

​Properties

​IsUpdateAvailable

​LatestVersion

​InstallerDownloadUrl

​Events

​StateChanged

​Types

​DownloadProgress

​Methods

​CheckAsync(CancellationToken)

​DownloadAndInstallAsync(IProgress<DownloadProgress>?, CancellationToken)

Build docs developers (and LLMs) love

Static property

`CurrentVersion`

Properties

`IsUpdateAvailable`

`LatestVersion`

`InstallerDownloadUrl`

Events

`StateChanged`

Types

`DownloadProgress`

Methods

`CheckAsync(CancellationToken)`

`DownloadAndInstallAsync(IProgress<DownloadProgress>?, CancellationToken)`