c# - C#中如何判断一个线程是不是主线程

Question

还有其他帖子说你可以在windows窗体中创建一个控件，然后检查InvokeRequired属性来查看当前线程是否是主线程。

问题是您无法知道该控件本身是否是在主线程上创建的。

我使用下面的代码来判断一个线程是否是主线程(启动进程的线程):

if (Thread.CurrentThread.GetApartmentState() != ApartmentState.STA ||
    Thread.CurrentThread.ManagedThreadId != 1 ||
    Thread.CurrentThread.IsBackground || Thread.CurrentThread.IsThreadPoolThread)
{
    // not the main thread
}

有人知道更好的方法吗？看起来这种方式在运行时的 future 版本中可能容易出错或中断。

Answer 1

你可以这样做:

// Do this when you start your application
static int mainThreadId;

// In Main method:
mainThreadId = System.Threading.Thread.CurrentThread.ManagedThreadId;

// If called in the non main thread, will return false;
public static bool IsMainThread
{
    get { return System.Threading.Thread.CurrentThread.ManagedThreadId == mainThreadId; }
}

编辑 我意识到你也可以通过反射来做到这一点，这里有一个片段:

public static void CheckForMainThread()
{
    if (Thread.CurrentThread.GetApartmentState() == ApartmentState.STA &&
        !Thread.CurrentThread.IsBackground && !Thread.CurrentThread.IsThreadPoolThread && Thread.CurrentThread.IsAlive)
    {
        MethodInfo correctEntryMethod = Assembly.GetEntryAssembly().EntryPoint;
        StackTrace trace = new StackTrace();
        StackFrame[] frames = trace.GetFrames();
        for (int i = frames.Length - 1; i >= 0; i--)
        {
            MethodBase method = frames[i].GetMethod();
            if (correctEntryMethod == method)
            {
                return;
            }
        }
    }

    // throw exception, the current thread is not the main thread...
}