static ViewModelLocator()
{
ImageExService.ConfigureImageSource(options =>
{
options.WithDefaultServices();
options.WithDefaultPipes();
options.UseHttpHandler <BangumiHttpHandler>();
});
var autofacServiceLocator = new AutofacServiceLocator(ConfigureAutofacContainer());
ServiceLocator.SetLocatorProvider(() => autofacServiceLocator);
}
private async Task SetDesignSourceAsync(object?source)
{
if (_image == null)
{
return;
}
_lastLoadCts?.Cancel();
if (source == null)
{
AttachDesignSource(null);
VisualStateManager.GoToState(this, EmptyStateName, true);
return;
}
var loadCts = new CancellationTokenSource();
_lastLoadCts = loadCts;
try
{
IsLoading = true;
VisualStateManager.GoToState(this, LoadingStateName, true);
// 开始 Loading，重置 DownloadProgress
DownloadProgress = default;
var context = new LoadingContext <ImageSource>(_uiContext, source, AttachDesignSource, ActualWidth, ActualHeight);
context.DownloadProgressChanged += (sender, progress) =>
{
if (_uiContext != null)
{
_uiContext.Post(state =>
{
DownloadProgress = progress;
}, null);
}
else
{
DownloadProgress = progress;
}
};
var pipeDelegate = ImageExService.GetHandler <ImageSource>();
var retryCount = RetryCount;
var retryDelay = RetryDelay;
var policy = Policy.Handle <Exception>()
.WaitAndRetryAsync(retryCount, count => retryDelay, (ex, delay) =>
{
context.Reset();
});
await policy.ExecuteAsync(() => pipeDelegate.Invoke(context, loadCts.Token));
if (!loadCts.IsCancellationRequested)
{
VisualStateManager.GoToState(this, OpenedStateName, true);
if (_uiContext != null)
{
_uiContext.Post(state =>
{
ImageOpened?.Invoke(this, EventArgs.Empty);
}, null);
}
else
{
ImageOpened?.Invoke(this, EventArgs.Empty);
}
}
}
catch (Exception ex)
{
if (!loadCts.IsCancellationRequested)
{
AttachDesignSource(null);
VisualStateManager.GoToState(this, FailedStateName, true);
if (_uiContext != null)
{
_uiContext.Post(state =>
{
ImageFailed?.Invoke(this, new ImageExFailedEventArgs(source, ex));
}, null);
}
else
{
ImageFailed?.Invoke(this, new ImageExFailedEventArgs(source, ex));
}
}
}
finally
{
if (!loadCts.IsCancellationRequested)
{
IsLoading = false;
}
}
}