使用下拉菜单筛选GridView

本文关键字：GridView 筛选 下拉菜单 | 更新日期: 2023-09-27 18:23:46

我在这方面已经陷得太久了，我的Google Fu让我失望了。我是C#和.Net的新手，所以我在这里很沮丧。

到目前为止，我拥有的是：

一个名为GetData的方法填充一个DataSet，然后我从中创建一个DataTable。

我将DataTable绑定到GridView，然后使其可排序。表和排序工作得很好，但我需要对一些列进行下拉筛选，但我什么都做不到。

我的ASP:

<asp:GridView id="gvEvaluator" Runat="server" Width="750" tooltip="Evaluator Status"     AutoGenerateColumns="False" 
EnableViewState="true" 
HeaderStyle-ForeColor="#000000"
HeaderStyle-BackColor="#CCCCCC" 
FooterStyle-ForeColor="#000000" 
FooterStyle-BackColor="#CCCCCC" 
Font-Size="8pt" 
Font-Names="Verdana" 
CellSpacing="0" 
CellPadding="3" 
ShowFooter="true" 
AllowSorting="true" 
GridLines="Both" 
BorderColor="#ffffff" 
BackColor="#ffffff"
ItemStyle-HorizontalAlign="Left"
visible="true"
AllowPaging="false"
AllowCustomPaging="false"
OnSorting="GridView_Sorting">
    <Columns>
        <asp:TemplateField HeaderText="<strong>Term</strong>"
            HeaderStyle-HorizontalAlign="Center" HeaderStyle-VerticalAlign="Bottom"
            ItemStyle-HorizontalAlign="Center" ItemStyle-VerticalAlign="top" >
                <HeaderTemplate>
                    <asp:DropDownList ID="ddlTerm"
                        runat="server"
                        visible="true"
                        OnSelectedIndexChanged="ddlTermChanged"
                        AutoPostBack="true"
                        DataSourceID="gvEvaluator">
                    </asp:DropDownList>
                </HeaderTemplate>
        </asp:TemplateField>
<asp:BoundField DataField="Dept" HeaderText="Dept" SortExpression="Dept></asp:BoundField>
<asp:BoundField DataField="Course" HeaderText="Course" SortExpression="Course"></asp:BoundField>
<asp:BoundField DataField="Section" HeaderText="Section"></asp:BoundField>
<asp:BoundField DataField="Evaluator" HeaderText="Evaluator" SortExpression="Evaluator"></asp:BoundField>
<asp:BoundField DataField="Type" HeaderText="Evaluator Type"></asp:BoundField>
<asp:BoundField DataField="Email_Address" Visible="false"></asp:BoundField>
<asp:BoundField DataField="Days_Since_Login" HeaderText="Days Since Login"></asp:BoundField>
<asp:BoundField DataField="Required_Work" HeaderText="Required Work" SortExpression="Required_Work"></asp:BoundField>
<asp:BoundField DataField="Total_Assigned" HeaderText="Total Assigned" HeaderStyle-HorizontalAlign="Right" ItemStyle-HorizontalAlign="Right"></asp:BoundField>
<asp:BoundField DataField="Total_Not_Started" HeaderText="Total Not Started" HeaderStyle-HorizontalAlign="Right" ItemStyle-HorizontalAlign="Right"></asp:BoundField>
<asp:BoundField DataField="Total_in_Progress" HeaderText="Total in Progress" HeaderStyle-HorizontalAlign="Right" ItemStyle-HorizontalAlign="Right"></asp:BoundField>
<asp:BoundField DataField="Total_Complete" HeaderText="Total Complete" HeaderStyle-HorizontalAlign="Right" ItemStyle-HorizontalAlign="Right"></asp:BoundField>
<asp:BoundField DataField="eval_id" Visible="false"></asp:BoundField>
<asp:TemplateField HeaderText="<strong>Need Reminder<strong>" ItemStyle-Width="250px">
                  <ItemTemplate>
                  <label for="hyplEvaluator" class="hide">Email Evaluator</label> 
                  <asp:HyperLink ID="hyplEvaluator" runat="server" CssClass="BodyLink" Text='<%# DataBinder.Eval(Container, "DataItem.Need_Reminder")%>' NavigateUrl='' />
                  </ItemTemplate>
                  </asp:TemplateField>
</Columns>
</asp:GridView>

还有我的C#：

protected void getEvaluatorStatus()
    {
        try
        {
            ds = GetData();
            DataTable myTable = ds.Tables[0];
            if (myTable.Rows.Count != 0)
            {
                gvEvaluator.DataSource = ds;
                gvEvaluator.DataBind();
                gvEvaluator.Visible = true;
                lblNoAssignment.Visible = false;
            }
            else
            {
                lblNoAssignment.Visible = true;
                gvEvaluator.Visible = false;
            }
            //Adds attributes to hyplEmailContact
            for (int i = 0; i < gvEvaluator.Rows.Count; i++)
            {
                string inSenderID = Convert.ToString(meth.decrypt(Session["UserID"].ToString(), Convert.ToString(Session["University"]), Convert.ToString(Session["Department"])));
                string inRecptID = Convert.ToString(gvEvaluator.Rows[i].Cells[10].Text);
                //custom string of attributes above
                string customStr = "inSenderID=" + inSenderID + ",inRecptID=" + inRecptID;
                //Adds the NavigateURL for Contact command to pass variables/attributes 
                HyperLink hyplEmailContact = (HyperLink)gvEvaluator.Rows[i].FindControl("hyplEvaluator");
                hyplEmailContact.NavigateUrl = "javascript:openEmailGeneral(" + customStr + ")";
            } //End for loop 
        }
        catch (Exception ex)
        {
            Session["Error_Code"] = ex;
            Response.Redirect("../Error.aspx");
        }

我只是一个低级的bug压扁者，所以我个人写的唯一代码就是创建GridView（从DataGrid）、GetData方法，使其可排序，并使数据可导出。

使用下拉菜单筛选GridView

这样的东西应该可以工作：

  1. 处理ddlTermChanged更改事件：

  2. 在下拉列表中抓取新选择的值，这样

    protected void ddlTermChanged(Object sender, EventArgs e) {
    var newValue = ddlTerm.SelectedValue;
    //see step 3 below
}

  3. 现在过滤数据并将其重新绑定到Gridview；类似于：

    protected void ddlTermChanged(Object sender, EventArgs e) {
    var newValue = ddlTerm.SelectedValue;
    DataTable t=  GetDataByID(newValue);
    gvEvaluator.DataSource=t;
    gvEvaluator.DataBind();
}

另请注意，您在getEvaluatorStatus方法内对Gridview进行的所有转换都应该在OnRowDataBound事件中处理。通过按您的方式执行，每次重新绑定数据（如在筛选的情况下）时，您都必须在getEvaluatorStatus中重复代码才能再次执行转换。如果执行OnRowDataBound，则不必重复代码，因为在绑定每一行时都会引发事件。

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