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对WPF中非UI对象的跨线程访问

[英]Cross-thread access to non-ui object in wpf

原文 2010-02-05 14:30:50 5 1 c#/ backgroundworker

I'm having some problems using a backgroundworker in a WPF app. 我在WPF应用程序中使用backgroundworker时遇到一些问题。 Here's the situation: 情况如下：

I'm trying to do two things. 我正在尝试做两件事。 First scanning a number of images and then use barcode recognition on the scanned images. 首先扫描许多图像，然后在扫描的图像上使用条形码识别。 I'm retrieving the scanned images as a list of BitmapSource objects and these should be available to my backgroundworker thread. 我将扫描的图像作为BitmapSource对象的列表进行检索，并且这些应可用于我的backgroundworker线程。

After some googling it seems most solutions are specific to communication with ui elements on the main thread because none of the solutions I've found have worked for me. 经过一番谷歌搜索后，似乎大多数解决方案都是特定于与主线程上的ui元素进行通信的，因为我发现的所有解决方案都不适合我。 I've tried using delegates and the dispatcher but to no avail. 我尝试使用委托和调度程序，但无济于事。

I need the BitmapSources to create Bitmaps with them which is the input of the barcode recognition. 我需要BitmapSources与它们一起创建位图，这是条形码识别的输入。

Thanks, 谢谢，

Kevin 凯文

1 个解决方案

In WPF, all DispatcherObjects (not only UI elements) can be accessed only from the thread that created them. 在WPF中，只能从创建它们的线程访问所有DispatcherObjects （不仅是UI元素）。 BitmapSource inherits (indirectly) from DispatcherObject , so it follows this rule. BitmapSource （间接）继承自DispatcherObject ，因此它遵循此规则。 However, it also inherits from Freezable , and Freezable objects can be accessed from another thread if they are frozen . 但是，它也继承自Freezable ，如果 Freezable对象被冻结，则可以从另一个线程访问它们。

So, after your BitmapSource is initialized, you can call Freeze on it, and it will be accessible from other threads. 因此，在初始化BitmapSource之后，您可以对其调用Freeze ，并且可以从其他线程访问它。