控件禁用：readonly、enabled、disabled

如果页面开启就禁用，且需在page_loaded中加载，就需要这样写

protected void Page_Load(object sender, EventArgs e)
{

if (!IsPostBack)
{
if (Session["LoginUser"] == null)
{
Response.Redirect("../Login.aspx");
return;
}
else
{
txt_datetime.Attributes.Add("ReadOnly", "ReadOnly");
txt_carNumber.Attributes.Add("disabled", "true");

}

}
}

也可以在方法中写：

/// <summary>
/// 页面控件的可用性
/// </summary>
/// <param name="result">true：可用；false：禁用</param>
private void controlEnabled(bool result)
{
txt_gasolineCard.Enabled = result;
txt_carNumber.Enabled = result;
txt_firstBalance.Enabled = result;
imgSel.Visible = result;
}