asp.net - 为什么我提交时我的文本框无法识别值已更改？

Question

当我的页面加载时，它会查询数据库中的某些值并用它们填充一些文本框:

protected void Page_Load(object sender, EventArgs e)
{
    tadbDataContext tadb = new tadbDataContext();
    Dictionary<string, string> hexColors = tadb.msp_silentAuctionColors.ToDictionary(t => t.colorDescription, t => t.colorValue);

    tbTextColor.Text = hexColors["textColor"];
    tbAltColor.Text = hexColors["altColor"];
    tbBackgroundColor.Text = hexColors["backgroundColor"];
}

然后，我更改该值并尝试通过单击执行以下操作的按钮重新提交到数据库:

using (tadbDataContext tadb = new tadbDataContext())
{
    var textColor = tadb.msp_silentAuctionColors.Single(x => x.colorDescription == "textColor");

    var altColor = tadb.msp_silentAuctionColors.Single(x => x.colorDescription == "altColor");
    var backgroundColor = tadb.msp_silentAuctionColors.Single(x => x.colorDescription == "backgroundColor");

    textColor.colorValue = tbTextColor.Text;
    altColor.colorValue = tbAltColor.Text;
    backgroundColor.colorValue = tbBackgroundColor.Text;

    tadb.SubmitChanges();
}

回发的值是原始值(不是更改后的值)。如果我注释掉加载时填充文本框的行，它就可以正常工作。

Answer 1

那是因为您没有将数据绑定(bind)内容包装在 Page_Load 中的 IsPostBack 检查中。因此，您总是用数据库中的旧值覆盖更改后的值。

所以你只需这样做:

protected void Page_Load(object sender, EventArgs e)
{
    if(!Page.IsPostBack)
    {
        tadbDataContext tadb = new tadbDataContext();
        Dictionary<string, string> hexColors = tadb.msp_silentAuctionColors.ToDictionary(t => t.colorDescription, t => t.colorValue);

        tbTextColor.Text = hexColors["textColor"];
        tbAltColor.Text = hexColors["altColor"];
        tbBackgroundColor.Text = hexColors["backgroundColor"];
    }
}