如何将下拉列表添加为gridview项

你的问题有三个部分:

如何在GridView中添加DropDownList？

如何从GridView中的DropDownList中获取所选项？

如何计算值并在GridView中显示？

这是我们如何做到的.首先在页面中添加此标记.我为产品名称添加了一个列,使其看起来更好:

<asp:GridView ID="GridView1" AutoGenerateColumns="false" runat="server" OnRowDataBound="GridView1_RowDataBound">
    <Columns>
        <asp:BoundField DataField="Name" HeaderText="Name" />
        <asp:TemplateField HeaderText="Quantity">
            <ItemTemplate>
                <asp:DropDownList ID="ddlQuantity" runat="server" AutoPostBack="true" OnSelectedIndexChanged="ddlQuantity_SelectedIndexChanged"></asp:DropDownList>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="Price">
            <ItemTemplate>
                <asp:Label ID="lblPrice" Text='<%#Eval("Price") %>' runat="server" ></asp:Label>
            </ItemTemplate>

        </asp:TemplateField>
        <asp:TemplateField HeaderText="Amount">
            <ItemTemplate>                        
                <asp:Label ID="lblAmount" Text="0.00" runat="server" ></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>

如何在GridView中添加DropDownList

在Page_Load()中填充GridView(我使用了产品列表):

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        //Test data to populate GridView
        GridView1.DataSource = new List<Product>()
        {
            new Product{ID=1, Name="Paper", Price=7.99M},
            new Product{ID=2, Name="Pen", Price=14.99M},
            new Product{ID=3, Name="Pencil", Price=1.99M}
        };

        GridView1.DataBind();
    }
}

这将触发GridView的RowDataBound事件.在event方法中,我们将在每行中绑定DropDownList,如下所示:

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        var ddl = e.Row.FindControl("ddlQuantity") as DropDownList;
        if (ddl != null)
        {
            ddl.DataSource = new List<string>() { "0", "1", "2", "3", "4" };
            ddl.DataBind();
        }
    }
}

如何从GridView中的DropDownList中获取所选项目

如何计算值并在GridView中显示

当您更改DropDownList中的任何选择时,它将触发SelectedIndexChange事件.在那个事件方法中,我们可以找到哪个DropDownList被更改,而且它的"NamingContainer" - GridView的行保存它:

protected void ddlQuantity_SelectedIndexChanged(object sender, EventArgs e)
{
    GridViewRow gvr = ((DropDownList)sender).NamingContainer as GridViewRow ;
    if (gvr != null)
    {
        decimal price = 0.00M;
        int quantity = 0;
        //We can find all the controls in this row and do operations on them
        var ddlQuantity = gvr.FindControl("ddlQuantity") as DropDownList;
        var lblPrice = gvr.FindControl("lblPrice") as Label;
        var lblAmount = gvr.FindControl("lblAmount") as Label;
        if (ddlQuantity != null && lblPrice != null && lblAmount != null)
        {
            int.TryParse(ddlQuantity.SelectedValue, out quantity);
            decimal.TryParse(lblPrice.Text, out price);

            lblAmount.Text = (price * quantity).ToString();
        }    
    }
}

这是结果:

您可以在此处下载测试项目.