假设你在XAML中有一个名为image的Image元素，并且你的png文件的路径在一个名为imagePaths的List<string>中，你可以使用一个计时器：

private void UpdateLoadingBar()
{
    var frameIndex = 0;
    var frameCount = imagePaths.Count;
        
    var timer = new DispatcherTimer();
    timer.Interval = TimeSpan.FromMilliseconds(100);
    timer.Tick += (sender, e) =>
    {
        loadingImage.Source = new BitmapImage(
            new Uri(imagePaths[frameIndex], UriKind.RelativeOrAbsolute));

        if (++frameIndex >= frameCount)
        {
            // Stop the timer when all frames have been displayed
            timer.Stop();
        }
    };

    timer.Start();
}

或者如果你熟悉异步编程，你可以使用

private async Task UpdateLoadingBar()
{
    foreach (var imagePath in imagePaths)
    {
        loadingImage.Source = new BitmapImage(
            new Uri(imagePath, UriKind.RelativeOrAbsolute));

        // Delay between each frame (adjust the duration as needed)
        await Task.Delay(100);
    }
}

这需要从异步事件处理程序启动，如：

private async void StartLoadingButton_Click(object sender, RoutedEventArgs e)
{
    await UpdateLoadingBar();
}