如何运行的东西在STA线程？ [英] How to run something in the STA thread?

问题描述

在我的WPF应用程序我做了一些异步通信（与服务器）。在回调函数中我最终从服务器的结果产生墨水presenter对象。这需要运行的线程是STA，这显然它目前不是。因此，我得到了以下异常：

  

无法创建的水墨presenter汇编定义的实例[..]调用线程必须STA，因为许多UI组件都需要这个。

目前我的异步函数调用是这样的：

 公共无效SearchForFooAsync（字符串searchString）
{
    VAR来电=新的函数功能：LT;字符串，富＆GT;（_ patientProxy.SearchForFoo）;
    caller.BeginInvoke（searchString，新的AsyncCallback（SearchForFooCallbackMethod），NULL）;
}
 

我怎样才能让回调 - 这将做墨水presenter创作 - 是STA？或者调用的XamlReader分析在一个新的STA线程。

 公共无效SearchForFooCallbackMethod（IAsyncResult的AR）
{
    无功富= GetFooFromAsyncResult（AR）;
    VAR油墨presenter = XamlReader.Parse（foo.Xaml）作为油墨presenter; //＆所述;！ - 需要STA
    [..]
}
 

解决方案

您可以启动STA线程像这样：

 线程的线程=新主题（MethodWhichRequiresSTA）;
    thread.SetApartmentState（ApartmentState.STA）; //设置线程STA
    thread.Start（）;
    的Thread.join（）; //等待线程结束
 

唯一的问题是，你的结果对象必须同时在某种程度上跳水过去了。你可以使用一个私有字段为，或进入沿参数传递到线程。在这里，我在一个私有字段设置foo的数据，并启动STA线程变异油墨presenter！

 私人变种FOO;
公共无效SearchForFooCallbackMethod（IAsyncResult的AR）
{
    富= GetFooFromAsyncResult（AR）;
    线程线程=新主题（ProcessInk presenter）;
    thread.SetApartmentState（ApartmentState.STA）;
    thread.Start（）;
    的Thread.join（）;
}

私人无效ProcessInk presenter（）
{
    VAR油墨presenter = XamlReader.Parse（foo.Xaml）作为油墨presenter;
}
 

希望这有助于！

In my WPF application I do some async communication (with server). In the callback function I end up creating InkPresenter objects from the result from server. This requires the running thread to be STA, which apparently it currently isn't. Therefore I get the following exception:

Cannot create instance of 'InkPresenter' defined in assembly [..] The calling thread must be STA, because many UI components require this.

Currently my async function call is like this:

public void SearchForFooAsync(string searchString)
{
    var caller = new Func<string, Foo>(_patientProxy.SearchForFoo);
    caller.BeginInvoke(searchString, new AsyncCallback(SearchForFooCallbackMethod), null);
}

How can I make the callback - which will do the InkPresenter creation - be STA? Or invoke the XamlReader parsing in a new STA thread.

public void SearchForFooCallbackMethod(IAsyncResult ar)
{
    var foo = GetFooFromAsyncResult(ar); 
    var inkPresenter = XamlReader.Parse(foo.Xaml) as InkPresenter; // <!-- Requires STA
    [..]
}

解决方案

You can start STA Threads like so:

    Thread thread = new Thread(MethodWhichRequiresSTA);
    thread.SetApartmentState(ApartmentState.STA); //Set the thread to STA
    thread.Start(); 
    thread.Join(); //Wait for the thread to end

The only problem is that your result object must be passed along somehow.. You can use a private field for that, or dive into passing along parameters into threads. Here I set the foo data in a private field and start up the STA Thread to mutate the inkpresenter!

private var foo;
public void SearchForFooCallbackMethod(IAsyncResult ar)
{
    foo = GetFooFromAsyncResult(ar); 
    Thread thread = new Thread(ProcessInkPresenter);
    thread.SetApartmentState(ApartmentState.STA);
    thread.Start();
    thread.Join(); 
}

private void ProcessInkPresenter()
{
    var inkPresenter = XamlReader.Parse(foo.Xaml) as InkPresenter;
}

Hope this helps!

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