从两个下拉列表中删除同一项目 [英] Removing same item from two dropdown list

问题描述

大家好，我要在我的注册表中添加两个下拉列表.第一个下拉列表绑定到数据库，第二个下拉列表也来自同一表.如果我从firstdropdownlist中选择一个项目，则从第二个dropdownlist中删除该项目.对我来说没关系，但是问题是我单击了firstdropdown列表的所有项目，而不是第二个dropdownlist变为空.请参阅我的代码

Hi to all, i am adding two dropdown list in my registration form. the first dropdownlist is bind to database, and second dropdownlist also from same table. if i select a item from firstdropdownlist it remove the item from second dropdownlist. That is Ok for me, but the problem is that i click all item of firstdropdown list than the second dropdownlist become empty.. See my code

<asp:DropDownList ID="DrpPrefLangauge1"

                  AppendDataBoundItems ="true"

                  OnSelectedIndexChanged="DrpPrefLangauge1_SelectedIndexChanged"  

                  runat="server"

                  AutoPostBack="True">
    <asp:ListItem Text="----Select----" 

                  Value="0">
    </asp:ListItem>
</asp:DropDownList> 

<asp:DropDownList ID="DrpPrefLangauge2"

                  AppendDataBoundItems="true"

                  runat="server">
    <asp:ListItem Text="----Select----"

                  Value="0">
    </asp:ListItem>
</asp:DropDownList>

在后面的代码中:

At code behind:

protected void setLangauge()
{
    nsBusinessLogicLayer.LanguageInfo objLanguageInfo = new nsBusinessLogicLayer.LanguageInfo();
    nsAbstractLayer.LanguageInfoAbstract objLanguageInfoAbstract = new nsAbstractLayer.LanguageInfoAbstract();
    //objLanguageInfoAbstract.Languageid = Convert.ToInt64(DrpPrefLangauge1.SelectedValue);

    DataTable dt = objLanguageInfo.Search(objLanguageInfoAbstract);

    DrpPrefLangauge1.DataSource     = dt;
    DrpPrefLangauge1.DataTextField  = "LanguageName";
    DrpPrefLangauge1.DataValueField = "Languageid";
    DrpPrefLangauge1.DataBind();

    DrpPrefLangauge2.DataSource     = dt;
    DrpPrefLangauge2.DataTextField  = "LanguageName";
    DrpPrefLangauge2.DataValueField = "Languageid";
    DrpPrefLangauge2.DataBind();
}

在选定的索引上:

ON selected index:

protected void DrpPrefLangauge1_SelectedIndexChanged(object sender, EventArgs e)
{
    ListItem  value = DrpPrefLangauge1.SelectedItem;
    //int index=DrpPrefLangauge2.Items.IndexOf(value);
    DrpPrefLangauge2.Items.Remove(value);
}

我想如果我从firstdownlist中选择说印地文langauge，它将在第二个dropdownlist中删除.这是可行的，但是如果我从我的第一个downlist中选择所有项目，则第二个dropdownlist变为空..这就是问题的解决方法..

I want if i select say hindi langauge from firstdownlist , it will remove in second dropdownlist.. this is working but if i select all item from my first downlist the second dropdownlist become empty..that is the problem how it solve it..

推荐答案

如果您打算保留除DrpPrefLanguage1中所选项目之外的所有项目，则必须在删除该项目之前重新绑定DrpPrefLanguage2.

希望对您有所帮助.

-------------------------------------------------- -------------
签名:瓜达卢斯伊比利亚州

If your intention is to keep all items with the exception of the selected item in DrpPrefLanguage1, you must rebind DrpPrefLanguage2 before removing the item.

I hope this helps.

---------------------------------------------------------------
Signature: Imobiliárias em Guarulhos

您不能同时拥有这两种方式.如果您希望在选择某个项目时将其删除，那么在选择所有项目时，它们都将被删除.

You can''t have it both ways. If you want an item removed when selected then when selecting all items they will all be removed.

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