c# - 如何将迭代更改为反应式 (Rx)

Question

我想将以下代码更改为基于 Observable：

// 'assets' is a IReadOnly list of StorageFile (approx. 10-20 files)
foreach (var file in assets)
{
    img.Source = new BitmapImage(new Uri(file.Path));

    img.ImageOpened += async (sender, e) =>
    {
        // Do some work (can contain Task-based code)
    };
}

但是当我尝试改变它时，我最终遇到了一些设计问题：

assets
    .ToObservable()
    .Select(file =>
    {
        img.Source = new BitmapImage(new Uri(file.Path));
        return img.Events().ImageOpened;
    })
    .Switch()
    .Select(event =>
    {
        // Now I'm stuck, I don't have the file...
    })
    .Subscribe(
        _ =>
        {               
        },
        ex => System.Diagnostics.Debug.WriteLine("Error on subscribing to ImageOpened"))
    .DisposeWith(_subscriptions);

我觉得我走错了路……

Answer 1

最后，由于图像控件的另一个限制，我需要更改逻辑，但我的解决方案是使用 Zip 的以下方向：

Observable
    .Zip(
        assets
            .ToObservable()
            .Do(file => imageControl.Source = new BitmapImage(new Uri(file.Path))),
        imageControl
            .Events()   // Extension class for my events
            .ImageOpened,
        (asset, _) =>
        {
            // Do some work ...
        })
    .Subscribe(
        _ => { },
        ex => System.Diagnostics.Debug.WriteLine("Error on subscribing to Zip"));
    .DisposeWith(_subscriptions);