WPF Image.Source缓存太积极 [英] WPF Image.Source caching too aggressively

问题描述

我有 System.Windows.Controls.Image 的实例，我编程设置内容，例如：

I have an instance of System.Windows.Controls.Image, and I set the contents programmatically as such:

Uri location = new Uri(uriString);
image.Source = new BitmapImage(location);

有时候，我知道在服务器上的形象已经改变了，我想刷新，但每次我重复上述code，我得到了相同的图像。

Sometimes I know that the image on the server has changed and I want to refresh it, but every time I repeat the above code I get the same image.

这似乎是一个缓存的问题，但两个明显的解决方案 - RequestCacheLevel 和 BitmapCacheOption - 似乎做什么都没有。这code具有相同的结果：

This seems to be a caching problem, but the two obvious solutions — RequestCacheLevel and BitmapCacheOption — seem to do nothing. This code has the same result:

var cachePolicy = new RequestCachePolicy(RequestCacheLevel.NoCacheNoStore)) {
    CacheOption = BitmapCacheOption.None
};
image.Source = new BitmapImage(location, cachePolicy);
// Still uses the cached version.

我发现强制刷新的唯一方法是追加一次性查询字符串的URI，这似乎是工作，更是一个完整的黑客：

The only way I've found to force a refresh is to append a throwaway query string to the URI, which seems to work, but also is a complete hack:

Uri location = new Uri(uriString + "?nonsense=" + new Random().Next());
image.Source = new BitmapImage(location);
// This forces a refresh

我怎样才能prevent从这些图像被缓存，和/或强制刷新？

How can I prevent these images from being cached, and/or force a refresh?

推荐答案

我想你需要设置上的BitmapImage的CreateOptions为：

I think you need to set the CreateOptions on the BitmapImage to:

BitmapCreateOptions.IgnoreImageCache

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