在工作线程中调用时，任务死锁

我有一个windows窗体程序(**VS 2010 . net 4 **)，检测递归文件夹和子文件夹的目录和优化文件。我通过任务库和有一个进度条，显示项目的进度和标签附近的进度条显示当前文件来做到这一点。我有一个SetText(字符串文本)方法和委托(委托无效SetTextCallback(字符串文本);)用于此目的。当我想在进程结束时显示一个消息框时，我认为它死锁了。但是当我在button6_Click中不使用task.Wait();时，它会正常运行，UI不会挂起。这是我的代码:

    public partial class Form1 : Form
    {

int MaxFileCounter = 0;
    static int FileCounter = 0;
delegate void SetTextCallback(string text);
delegate void SetProgressCallback(int i);
private void button6_Click(object sender, EventArgs e)
{
    Task task = Task.Factory.StartNew(() =>
    {
        editFiles(txtFilePath.Text);
    });
    task.Wait();
    MessageBox.Show("finished");
}
private void editFiles(string directoryPath)
{
    try
    {
        //DirectoryInfo dirInfo = new DirectoryInfo(txtFilePath.Text);
        DirectoryInfo dirInfo = new DirectoryInfo(directoryPath);
        //string[] extensionArray = { ".jpg", ".png", ".gif" ,".jpeg"};
        string[] extensionArray = txtExtensionList.Text.Split(';');
        HashSet<string> allowedExtensions = new HashSet<string>(extensionArray, StringComparer.OrdinalIgnoreCase);
        FileInfo[] files = Array.FindAll(dirInfo.GetFiles(), f => allowedExtensions.Contains(f.Extension));
        writeFiles(files);
        foreach (DirectoryInfo dir in dirInfo.GetDirectories())
        {
            editFiles(dir.FullName);
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
}
private void writeFiles(FileInfo[] files)
{
    try
    {
        foreach (FileInfo fileinfo in files)
        {
            MemoryStream mo;
            using (Image image = Image.FromFile(fileinfo.FullName))
            {
                SetText(fileinfo.FullName);
                FileCounter++;
                SetProgress(FileCounter * 100 / MaxFileCounter);
                mo = (MemoryStream)optimizeImage(image, int.Parse(txtPercent.Text));
            }
            byte[] bt = new byte[mo.Length];
            mo.Read(bt, 0, bt.Length);
            mo.Flush();
            mo.Close();
            string fullpath = fileinfo.FullName;
            File.WriteAllBytes(fullpath, bt);
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
}
private void SetText(string text)
{
    // InvokeRequired required compares the thread ID of the
    // calling thread to the thread ID of the creating thread.
    // If these threads are different, it returns true.
    if (lblFileName.InvokeRequired)
    {
        SetTextCallback d = new SetTextCallback(SetText);
        this.Invoke(d, new object[] { text });
    }
    else
    {
        this.lblFileName.Text = text;
    }
}
private void SetProgress(int i)
{
    if (progressBar1.InvokeRequired)
    {
        SetProgressCallback p = new SetProgressCallback(SetProgress);
        this.Invoke(p, new object[] { i });
    }
    else
    {
        this.progressBar1.Value = i;
    }
}
}

我该如何处理?

    this.Invoke(d, new object[] { text });