Thread th = new Thread(delegate() {
　　append();
});
th.IsBackground = true;
th.Start();

//在append方法里面需要調用前臺控件

public void append(){

　　// ... 業務處理　　

　　this.Invoke(new flushMessage(showMessage), new object[] { row["Code"].ToString(), res });
}

//委托flushMessage和方法showMessage簽名必須一致
private delegate void flushMessage(String id, String res);
private void showMessage(String id,String res)
{
if (res == "true")
{
txtMsg.Text += "/t/t/t/t" + id + "/t/t/t/t導入成功/r/n";
}
else
{
txtMsg.Text += "/t/t/t/t" + id + "/t/t/t/t/t導入失敗/r/n";
}
}