当使用字体时，WPF TextBlock内存泄漏

I'm using .NET 4.5 on Windows 7, and might find a memory leak.
I have a TextBlock (not TextBox - it's not the Undo problem), which changes its value every second (CPU usage, time, etc...).
Using .NET Memory Profiler (and by simply watching task manager) I noticed the memory keeps on growing. To be more accurate, I see more and more live instances of UnmanagedMemoryStream (I tried GC.Collect() which obviously didn't do anything).

我正在Windows 7上使用。net 4.5，可能会发现内存泄漏。我有一个TextBlock(不是TextBox -它不是撤消问题)，它每秒钟都会改变它的值(CPU使用量，时间等等)。使用。net内存分析器(通过简单地查看任务管理器)，我注意到内存一直在增长。更准确地说，我看到越来越多的UnmanagedMemoryStream的活动实例(我尝试了GC.Collect()，显然它什么也没做)。

After some tests, I've found out that this problem appears only when I'm setting the TextBlock font to a resource font as follows:

经过一些测试，我发现只有当我将TextBlock字体设置为资源字体时才会出现这个问题，如下所示:

<Style TargetType="{x:Type TextBlock}">
    <Setter Property="Control.Foreground" Value="#CCCCCC"/>
    <Setter Property="FontFamily" Value="pack://application:,,,/MyUIControls;component/./Fonts/#Noto Sans"/>
</Style>

I tried updating the Text property directly from code or via Binding, it behaves the same for both ways.

我尝试直接从代码或通过绑定更新文本属性，两种方式的行为都是一样的。

Bottom line:
When the FontFamily is set, instances of UnmanagedMemoryStream keep on coming (forever) each time I'm updating the text. When I don't (set the FontFamily property), memory is stable.
(BTW, it happens when I use Label instead of TextBlock as well)

底线:当设置FontFamily时，UnmanagedMemoryStream的实例每次更新文本时(永远)都会出现。当我不(设置FontFamily属性)时，内存是稳定的。(顺便说一句，当我使用Label而不是TextBlock时也会发生)

It looks like a memory leak but I couldn't find any reference about it.
Any suggestions of how can it be solved?

它看起来像是内存泄漏，但我找不到任何有关它的引用。对如何解决这个问题有什么建议吗?

1 个解决方案

#1

A FontFamily leaks UnmanagedMemoryStreams when it is used if it was sourced from an embedded resource or a relative path. When the FontFamily is sourced from a system font or absolute path, it does not leak.

如果FontFamily来自嵌入式资源或相对路径，那么当它被使用时，它会泄漏UnmanagedMemoryStreams。当FontFamily来自系统字体或绝对路径时，它不会泄漏。

You can look here and download the project that reproduces the problem.

您可以查看这里并下载重新生成问题的项目。

Workaround: For Resource fonts: save fonts into a temporary folder and use the absolute path to the stored font. For relative path fonts: resolve and use the absolute path instead.

工作区:用于资源字体:将字体保存到临时文件夹中，并使用存储字体的绝对路径。对于相对路径字体:解析并使用绝对路径。

#1