删除窗口的背景图片WPF [英] Deleting a window's background image WPF

问题描述

我在WPF中遇到一个问题，即在应用程序的另一部分尝试写入图像之前，窗口在关闭后没有释放它在背景图像文件上的文件锁.

I'm having a problem in WPF where a window doesn't release it's file-lock on the background image file after closing, before another part of the application tries to write to the image.

举个例子；说我有一个WPF应用，该应用包含3个窗口，1个菜单"选择窗口和2个其他窗口.这两个窗口都使用 BitmapImage 作为 ImageSource (相同图像)来创建 ImageBrush .

So as an example; say I have a WPF app consisting of 3 windows, 1 "menu" selection window and 2 others. Both of the windows create an ImageBrush using a BitmapImage as the ImageSource (the same image).

窗口A具有一个按钮，当按下该按钮时，通过将可用的背景图像复制到用作原始 ImageSource 的文件上并创建新的 ImageBrush 来循环显示可用的背景图像，然后将 Window.Background 设置为新的画笔.

Window A has a button that when pressed, cycles through the available background images by copying them each over the file used as the original ImageSource and creating a new ImageBrush and setting the Window.Background to the new brush.

窗口B仅使用 ImageBrush 绘制 Window.Background .

如果启动了窗口A，切换了背景，关闭了窗口，然后启动了窗口B，则一切正常.

If Window A is launched, backgrounds switched, closed and then Window B launched, everything is fine.

如果启动并关闭了窗口B，则将启动窗口A，并且切换背景的窗口崩溃.尝试切换背景会引发 IOException ，因为:

If Window B is launched, closed, then Window A is launched and backgrounds switched it crashes. Trying to switch the backgrounds throws an IOException because:

该进程无法访问文件'C:\ Backgrounds \ Background.png'，因为它正在被另一个进程使用."

"The process cannot access the file 'C:\Backgrounds\Background.png' because it is being used by another process."

因此，窗口B必须仍然以某种方式保持住它！?我试过做一个 GC.Collect();GC.WaitForPendingFinalizers(); 看看是否可以解决问题，但不能解决.

So Window B must still be holding onto it somehow!? I have tried doing a GC.Collect(); GC.WaitForPendingFinalizers(); to see if that cures the problem but it doesn't.

推荐答案

Thomas给出的答案是正确的，并且如果您有文件路径，不想缓存位图并且不想使用它，效果很好.XAML.

The answer Thomas gave is correct, and works well if you have a file path, don't want to cache the bitmap, and don't want to use XAML.

不过，还应该提到BitmapImage具有通过设置BitmapCacheOption立即加载位图的内置方式:

However it should also be mentioned that BitmapImage has a built-in way to load the bitmap immediately by setting BitmapCacheOption:

BitmapImage img = new BitmapImage { CacheOption = BitmapCacheOption.OnLoad };
img.BeginInit();
img.UriSource = imageUrl;
img.EndInit();

或

<BitmapImage CacheOption="OnLoad" UriSource="..." />

这将立即加载位图并显式关闭流，就像使用FileStream一样，但有一些区别:

This will load the bitmap immediately and explicitly close the stream, just as using a FileStream would, but with several differences:

• 它可以与任何Uri一起使用，例如pack://Uri.
• 可以直接在XAML中使用
• 位图被缓存在位图缓存中，因此将来使用同一Uri不会进入磁盘.在您的特定应用中，这可能是一件坏事，但对于其他用途，则可能是理想的功能.

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