如何更新从代码隐藏
问题描述:
一个DropDownList的SqlDataSource的我有两个dropdownlists:如何更新从代码隐藏
<td style="width: 20%;">
<!-- TASK NAME -->
<asp:DropDownList ID="ddlTaskName" DataSourceID="dsPopulateTaskName" AutoPostBack="true" DataValueField="Task Name" runat="server" AppendDataBoundItems="true" OnSelectedIndexChanged="ddlTaskName_onSelectIndexChanged">
<asp:ListItem Text="All" Value="%"></asp:ListItem>
</asp:DropDownList>
<asp:SqlDataSource ID="dsPopulateTaskName" runat="server" ConnectionString="<%$ ConnectionStrings:gc %>" SelectCommand=""></asp:SqlDataSource>
</td>
<td style="width: 20%;">
<!-- SERVICE -->
<asp:DropDownList ID="ddlService" DataSourceID="dsPopulateService" AutoPostBack="true" DataValueField="Service" runat="server" AppendDataBoundItems="true" OnSelectedIndexChanged="ddlService_onSelectIndexChanged">
<asp:ListItem Text="All" Value="%"></asp:ListItem>
</asp:DropDownList>
<asp:SqlDataSource ID="dsPopulateService" runat="server" ConnectionString="<%$ ConnectionStrings:gc %>" SelectCommand=""></asp:SqlDataSource>
</td>
代码隐藏在Page_Load
:
strForDropDownList = @" FROM [Db].[dbo].[table1] WHERE [stat] = 'A'";
string pol = " AND ";
if (ddlTaskName.SelectedIndex == 0)
{
pol += " ([tcol] LIKE '%' OR [tcol] IS NULL) AND ";
}
else
{
pol += " [tcol] = '" + ddlTaskName.SelectedValue.TrimEnd() + "' AND ";
}
if (ddlService.SelectedIndex == 0)
{
pol += " (scol LIKE '%' OR scol IS NULL) AND ";
}
else
{
pol += " scol = '" + ddlService.SelectedValue.TrimEnd() + "' AND ";
}
strWhere = pol;
dsPopulateTaskName.SelectCommand = @"SELECT DISTINCT [tcol] 'Task Name'" + strForDropDownList + strWhere;
dsPopulateService.SelectCommand = @"SELECT DISTINCT scol 'Service'" + strForDropDownList + strWhere;
页面加载时,一切都与%
开始,正确填充下拉列表。如果我选择从下拉列表ddlService
一个选项,dsPopulateTaskName.SelectCommand
显示正确的查询重新填充ddlTaskName
下拉列表,但它并没有更新。
请帮我解决这个问题。
答
你应该设置SelectCommand
后打电话ddlService.DataBind()
和ddlTaskName.DataBind()
,我的意思是象下面这样:
dsPopulateTaskName.SelectCommand =
@"SELECT DISTINCT [tcol] 'Task Name'" + strForDropDownList + strWhere;
ddlService.DataBind();
dsPopulateService.SelectCommand =
@"SELECT DISTINCT scol 'Service'" + strForDropDownList + strWhere;
ddlTaskName.DataBind();
希望它有助于
谢谢。我有这样的:'ddlTaskName.Items.Clear(); ddlTaskName.DataBind();'它工作正常,除了我失去了'应该始终存在的所有'。 – SearchForKnowledge 2015-03-13 14:55:16
你不必使用该行:ddlTaskName.Items.Clear();它会刷新数据绑定 – 2015-03-13 15:02:14
我试过了,它没有工作。让我再尝试一次。 – SearchForKnowledge 2015-03-13 15:05:56