如何将下拉列表添加为 gridview 项目

Question

我的表单在 gridview 中有三列。一个是数量（下拉列表）{如何添加这个数量下拉列表？}，其他是价格和数量。我想计算gridview中的金额。如果我选择数量“2”，那么它会计算数量*价格。如何获取 selectedindexchanged 属性以在 gridview 或任何其他选项中进行下拉？

如何在 gridview 项目中添加下拉列表？ 如何将值添加到gridview内的下拉列表中？ 如何编写selectedindexchanged事件的代码，用于asp.net中gridview中的下拉菜单？

Answer 1

您的问题分为三个部分：

• 如何在GridView中添加DropDownList？
• 如何从 GridView 中的 DropDownList 中获取选中项？
• 如何计算数值并在GridView中显示？

我们可以这样做。首先在页面中添加此标记。我为产品名称添加了一列以使其看起来更好：

<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。在事件方法中，我们将在每一行中绑定 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 内的 DropDownList 中获取所选项目和

如何计算数值并在GridView中显示

当您更改 DropDownList 中的任何选择时，将触发其 SelectedIndexChange 事件。在那个事件方法中，我们可以找到哪个 DropDownList 发生了变化，它也是“NamingContainer”——GridView 的行包含它：

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();
        }    
    }
}

结果如下：

您可以下载测试项目here。

Answer 2

试试这个示例代码。

<asp:GridView ID="grEventi" runat="server" BackColor="White" 
              ShowHeaderWhenEmpty="True" AutoGenerateColumns="False"
              BorderColor="#CCCCCC" BorderStyle="None" BorderWidth="1px"
              CellPadding="3" Width="100%" OnRowDataBound="grEventi_RowDataBound"
              onselectedindexchanged="grEventi_SelectedIndexChanged" >
    <SelectedRowStyle CssClass="selectedRow" />
    <Columns>
        <asp:BoundField DataField="Elenco Eventi" HeaderText="Evento" />
        <asp:TemplateField  ItemStyle-Wrap="false" ItemStyle-Width="150" HeaderText="Data Inizio">
            <ItemTemplate>
                <asp:Label ID="lbl_data" runat="server" Text="" Visible="false" > 
                </asp:Label>
                <asp:DropDownList ID="ddl_data" runat="server" Visible="false" OnSelectedIndexChanged="ddl_dat_SelectedIndexChanged"  ClientIDMode = "Static" class ="calendar">
                </asp:DropDownList>
            </ItemTemplate>
        </asp:TemplateField>
</Columns>       
</asp:GridView>

代码隐藏：

protected void ddl_dat_SelectedIndexChanged(object sender, EventArgs e)
{
    //your logic goes here
    string test = "";    
}

protected void grEventi_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {

e.Row.Attributes.Add("onclick", this.ClientScript.GetPostBackEventReference((Control)sender, "Select$" + e.Row.RowIndex));

        DropDownList ddl_dat = (DropDownList)e.Row.FindControl("ddl_data");
        ddl_dat.SelectedValue = DataBinder.Eval(e.Row.DataItem, "data inizio").ToString();
        ddl_dat.Visible = true;
        ddl_dat.DataTextFormatString = "{0: ddd d/MM/yyyy HH:mm}";
        ddl_dat.DataTextField = "data inizio";
        ddl_dat.DataValueField = "data inizio";

        ddl_dat.DataSource = mydata;
        // ddl_dat.AutoPostBack = true;
        ddl_dat.DataBind();                
    }
    else 
    {
        Label lbl_data = (Label)e.Row.FindControl("lbl_data");
        lbl_data.Visible = true;
        DateTime date=(DateTime)dr.Row["data inizio"];

        lbl_data.Text = date.ToString("ddd d/MM/yyyy HH:mm");
    }
}

protected void grEventi_SelectedIndexChanged(object sender, EventArgs e)
{
    //my logic code
}

希望对您有所帮助。