private void buttonGetTokenStep2_Click(object sender, EventArgs e)
        {
            if (SessionId == "")
            {
                MessageBox.Show("无SessionId,请重新执行第一步", "抱歉", MessageBoxButtons.OK, MessageBoxIcon.Error);
                this.buttonGetTokenStep2.Enabled = false;
                this.buttonGetTokenStep1.Enabled = true;
                return;
            }

            this.buttonGetTokenStep2.Enabled = false;

            Token = EbayAccountBiz.FetchUserToken(SessionId, out UserName);

            this.textBoxToken.Text = Token;
        }