简单问题：请各位老大看下

private void btnSubmit_Click(object sender, System.EventArgs e)
{
    if(IsValid)
    {
        // Hide the form to set the value.
        pnlSetValue.Visible = false;
        username = txtName.Text;
        lblResult.Text = "Username set to " + txtName.Text + ".";
        lblUsername.Text = username;
        this.DataBind();
    }
}不明白 this.DataBind();
数据绑定不要指定映射关系么？:(