Databind下拉列表中包含＆​​＃34;请选择＆＃34;不工作

Question

我想在添加数据绑定后添加“请选择”项目到我的下拉列表但它似乎不起作用。这就是我想要的，

ddlListMine.Items.Add(new ListItem("Please Please Please Select....", "-1"));
ddlListMine.DataSource = GetSomeChickens();
ddListMine.DataTextField = "ChickenName";
ddListMine.DataValueField= "NumberOfEggsChickenLay";
ddListMine.DataBind();

我也尝试将第一行代码移动到最后，但随后“请取悦......”项目出现在下拉列表的末尾。

Answer 1

在Oth Index

插入您的项目

    ddlListMine.DataSource = GetSomeChickens();
    ddListMine.DataTextField = "ChickenName";
    ddListMine.DataValueField= "NumberOfEggsChickenLay";
    ddListMine.Items.Insert(0, new ListItem("Please Please Please Select....", "0"));
    ddListMine.DataBind();

Answer 2

试试这个，先绑定你的datalist，然后将空值listitem设置为选中。

ddlListMine.DataSource = GetSomeChickens();
ddListMine.DataTextField = "ChickenName";
ddListMine.DataValueField= "NumberOfEggsChickenLay";
ddListMine.DataBind();
ddlListMine.Items.Insert(0, new ListItem("Select Category", String.Empty));
ddListMine.SelectedIndex = 0;