Starting and joining a thread when the thread has starting parameters

In my code below I am taking files that are being dragged and dropped onto a button on my form, and processing them with a thread. I want to be able to have each thread complete it's operation before the foreach loop is continued and processes the next file.

I tried a

testthread().Join();

right after the

new Thread(()...

but it gets an error because it wants me to pass the same parameters that I pass to the testthread when I initially start the thread.

Can someone please show me the command and syntax I would use to accomplish the thread joining?

private void btnClick_DragDrop(object sender, DragEventArgs e)
{
    string[] file = (string[])e.Data.GetData(DataFormats.FileDrop);

    string ButtonName = "TestButton"

    string[] files = new string[10];

    files = (string[])e.Data.GetData(DataFormats.FileDrop);


    foreach (string file in files)
    {
        FileInfo fileInfo = new FileInfo(file);

        Console.WriteLine("++  Filename: " + fileInfo.Name + "   Date of file: " + fileInfo.CreationTime + "   Type of file: " + fileInfo.Extension + "   Size of file: " + fileInfo.Length.ToString());

        string Clea开发者_StackOverflow中文版nFileName = System.Web.HttpUtility.UrlEncode(fileInfo.Name.ToString());

        //Start  thread
        try
        {
            Console.WriteLine("++ Calling testthread with these params: false, " + ButtonName + "," + CleanFileName + "," + file);

            new Thread(() => testthread(false, ButtonName, CleanFileName, file)).Start();

            testthread().Join(); //THIS DOES NOT WORK BECAUSE IT WANTS THE PARAMETERS THAT THE THREAD IS EXPECTING.  WHAT CAN I PUT HERE SO IT WAITS FOR THE THREAD TO FINISH BEFORE CONTINUING THE FOREACH LOOP ?
         }
         catch (Exception ipwse)
         {
         Console.WriteLine(ipwse.Message + " " + ipwse.StackTrace);
         }
     }
}
public void testthread(bool CalledfromPendingUploads, string ButtonName, string CleanFileName, string FilePath)
{
    //My Code to do the file processing that I want done.  I do not want multiple threads to run at once here.  I need the thread to complete, then the foreach loop to continue to the next file and then start another thread and wait, etc...
}

If you are doing things serially, why do you need separate threads at all?

Thread t = new Thread(() => testthread(false, ButtonName, CleanFileName, file));
t.Start();
t.Join();

Edit:

Also it looks like you are executing your foreach loop on the UI thread - this will block the UI thread and is generally not a good thing to do for a long running operation. I'd suggest you move the looping code into a separate method that you execute on another thread, also get rid of the separate thread for each file processing.

var myThread = new Thread(...
myThread.Start();
myThread.Join();

And what you doing is calling the thread procedure, expecting it returns something that has method called "Join". Join is a method of Thread object. Construct the thread object and work with it.

Threads are not your answer here. If you need to wait for a thread to complete before you can start the next one, then you are going to run into the same bottleneck if you didn't use threads at all. However, if you using .NET 4.0, then the Parallel Task Library would definitely help you out here. Using Parallel Tasks, you could have your foreach loop run in parallel and speed up your program.