dropdown SelectedIndexChanged页面重新加载但值为null [英] dropdown SelectedIndexChanged page reload but value null
问题描述
嗨
i有2个下拉列表,onselectedindexchanged和autopostback true
当我点击dropdown1页面重新加载时,当前选择listitem是selectbox中的默认值..,我根据dropdown1值从数据库填充dropdown2 ..
然后当我点击dropdown2时,页面重新加载但是dropdown2选择的索引保持为0或空白
什么是错误
Hi
i have 2 dropdown with onselectedindexchanged and autopostback true
when i click dropdown1 the page reloads ,and current select listitem is default in selectbox.., i fill dropdown2 from database depending on dropdown1 value..
then when i click dropdown2 ,page reloads but the dropdown2 selected index remains 0 or blank
what is error
<asp:DropDownList ID="DropCity" AutoPostBack="True" onselectedindexchanged="DropCity_SelectedIndexChanged" runat="server" >
</asp:DropDownList>
<asp:DropDownList ID="DropCity1" AutoPostBack="True" onselectedindexchanged="DropCity1_SelectedIndexChanged" runat="server" >
</asp:DropDownList>
protected void DropCity1_SelectedIndexChanged(object sender, EventArgs e)
{
DropCity.DataSource();
DropCity.databing();
}
DropCity.DataSource();
DropCity.databing();
}
protected void DropCity_SelectedIndexChanged(object sender, EventArgs e)
{
}
请建议
}
please advice
推荐答案
在drp1的SelectedIndexChanged事件中将值绑定到drp2 ..
如果你没有对drp2索引改变事件进行任何操作,那么设置autopostback =false
使用以下属性
Bind the values to drp2 in drp1's SelectedIndexChanged event..
If you not doing any operation on drp2 index changed event then set autopostback = "false"
make use of properties as below
drp1.DataTextField = "Test1";
drp1.DataValueField = "TestID";
drp1.DataSource = dt;
drp1.DataBind();
为dropcity1设置autopostback = fasle
set autopostback =fasle for dropcity1
你好
i解决了..我在DropCountry中检查,如果Dropcity为null,则只填充它..
所以现在运行
Hi i solved it.. i check in DropCountry , if Dropcity is null ,then only fill it..
so this runs now
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