加快将rtf转换为纯文本

Question

我不得不将以RTF格式保存在数据库中的大量文本更改为纯文本。我正在使用方法described in this MSDN article但是我认为我发现了一个障碍（我认为它不在我的代码中，而是.NET框架本身）。

我有以下功能

    //convert RTF text to plain text
    public static string RtfTextToPlainText(string FormatObject)
    {
        System.Windows.Forms.RichTextBox rtfBox = new System.Windows.Forms.RichTextBox();
        rtfBox.Rtf = FormatObject;
        FormatObject = rtfBox.Text; //This is line 494 for later reference for the stack traces.
        rtfBox.Dispose();

        return FormatObject;
    }

它应该是完全独立的，不会阻挡任何东西。我正在做的项目有几百万条需要处理的记录，所以我分批分解工作并使用任务进行并行处理。它仍然相当慢，所以我闯入代码并发现了这一点。

这是等待任务的调用堆栈

[In a sleep, wait, or join] 
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.CreateHandle(System.Windows.Forms.CreateParams cp) + 0x242 bytes 
System.Windows.Forms.dll!System.Windows.Forms.Control.CreateHandle() + 0x2b2 bytes  
System.Windows.Forms.dll!System.Windows.Forms.TextBoxBase.CreateHandle() + 0x54 bytes   
System.Windows.Forms.dll!System.Windows.Forms.RichTextBox.Rtf.set(string value) + 0x68 bytes    
>CvtCore.dll!CvtCore.StandardFunctions.Str.RtfTextToPlainText(object Expression) Line 494   C#

这是线程816的调用堆栈

[Managed to Native Transition]  
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.DefWndProc(ref System.Windows.Forms.Message m) + 0x9e bytes  
System.Windows.Forms.dll!System.Windows.Forms.Control.WmWindowPosChanged(ref System.Windows.Forms.Message m) + 0x39 bytes   
System.Windows.Forms.dll!System.Windows.Forms.Control.WndProc(ref System.Windows.Forms.Message m) + 0x51b bytes 
System.Windows.Forms.dll!System.Windows.Forms.RichTextBox.WndProc(ref System.Windows.Forms.Message m) + 0x5c bytes  
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.DebuggableCallback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) + 0x15e bytes    
[Native to Managed Transition]  
[Managed to Native Transition]  
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.DefWndProc(ref System.Windows.Forms.Message m) + 0x9e bytes  
System.Windows.Forms.dll!System.Windows.Forms.Control.WmCreate(ref System.Windows.Forms.Message m) + 0x1c bytes 
System.Windows.Forms.dll!System.Windows.Forms.Control.WndProc(ref System.Windows.Forms.Message m) + 0x50b bytes 
System.Windows.Forms.dll!System.Windows.Forms.RichTextBox.WndProc(ref System.Windows.Forms.Message m) + 0x5c bytes  
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.DebuggableCallback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) + 0x15e bytes    
[Native to Managed Transition]  
[Managed to Native Transition]  
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.CreateHandle(System.Windows.Forms.CreateParams cp) + 0x44c bytes 
System.Windows.Forms.dll!System.Windows.Forms.Control.CreateHandle() + 0x2b2 bytes  
System.Windows.Forms.dll!System.Windows.Forms.TextBoxBase.CreateHandle() + 0x54 bytes   
System.Windows.Forms.dll!System.Windows.Forms.RichTextBox.Rtf.set(string value) + 0x68 bytes    
>CvtCore.dll!CvtCore.StandardFunctions.Str.RtfTextToPlainText(object Expression) Line 494   C#

为什么第494行任务4上的任务2阻塞，它们是否应该完全相互独立？

---

注意

我在发布模式下抓住了这些堆栈跟踪和屏幕截图，我似乎无法在正确的时间点击暂停以在调试模式下发生同样的事情。这也可能是我缓慢的原因吗？分析器说我的程序花费了83.2％的时间在`System.Windows.Forms.RichTextBox.set_Rtf（string）（这是第494行调用的子函数）

有关如何加快剔除rtf格式化过程的任何建议都将非常感激。

---

P.S。

我目前正在重写它，所以每个线程都有一个文本框，不会被处理掉，而不是每次调用该函数时都会创建一个新的文本框，我希望它能加快速度，我会更新细节在我这样做之后。

---

更新

我解决了自己的问题（见下面的答案），但这是我开始任务的方式

//create start consumer threads
for (int i = 0; i < ThreadsPreProducer; i++)
{
    //create worked and thread
    WorkerObject NewWorkerObject = new WorkerObject(colSource, FormatObjectEvent, UpdateModule);
    Task WorkerTask = new Task(NewWorkerObject.DoWork);
    WorkerTasks.Add(WorkerTask);
    WorkerTask.Start();
}


//create/start producer thread
ProducerObject NewProducerObject = new ProducerObject(colSource, SourceQuery, ConnectionString, PreProcessor, UpdateModule, RowNameIndex);
Task ProducerTask = new Task(NewProducerObject.DoWork);
WorkerTasks.Add(ProducerTask);
ProducerTask.Start();


//block while producer runs
ProducerTask.Wait();

//create post producer threads
for (int i = 0; i < ThreadsPostProducer; i++)
{
    //create worked and thread
    WorkerObject NewWorkerObject = new WorkerObject(colSource, FormatObjectEvent, UpdateModule);
    Task WorkerTask = new Task(NewWorkerObject.DoWork);
    WorkerTasks.Add(WorkerTask);
    WorkerTask.Start();
}

//block until all tasks are done
Task.WaitAll(WorkerTasks.ToArray());

正在使用生产者/消费者模型，在我的例子中，1个生产者和4个消费者（2个开始时开始，2个生产者完成后开始，以便在系统资源从生产者中释放后加速工作）。

Answer 1

将功能更改为

static ThreadLocal<RichTextBox> rtfBox = new ThreadLocal<RichTextBox>(() => new RichTextBox());
//convert RTF text to plain text
public static string RtfTextToPlainText(string FormatObject )
{
     rtfBox.Value.Rtf = FormatObject;
     FormatObject = rtfBox.Value.Text;
     rtfBox.Value.Clear();

     return FormatObject;
}

将我的运行时间从几分钟改为几秒钟。

我不处理这些物品，因为它们将用于整个程序的整个生命周期。