/// <summary>
    /// 执行登录事件
    /// </summary>
    protected void btnLogin_Click(object sender, EventArgs e)
    {
        //根据用户名得到用户密码
        string validatePwd = UserManager.GetUserPasswordByUserName(this.txtPassword.Text.Trim());
        //加密密码
        string inputPwd = CryptogramManager.EncryptPassword(this.txtPassword.Text.Trim());

        //通过对比密码,验证登录信息是否正确
        if (inputPwd.Trim() == validatePwd.Trim())
        {
            //保存用户身份
            userLigon.AuthenticationUsers(this.txtUserName.Text.Trim());
            if (!string.IsNullOrEmpty(ReturnUrl))
            {
                Response.Redirect(ReturnUrl);
            }
            else
            {
                Response.Redirect("Default.aspx");
            }
        }
        else
        {
            this.lblResult.Text = "您输入的用户名或密码不正确!";
        }
    }