Winform方式：

    if (this.InvokeRequired)

            {

                this.Invoke(

                    new Action (

                        delegate(Form form1)

                        {

                            lblTip.Content = msg;

                        })

                    , this

                );

            }

WPF方式：

            this.Dispatcher.BeginInvoke((Action)delegate()

            {

                lblTip.Content = msg;

            });