C# 制作动态下拉列表
我正在尝试以这种方式制作动态C# 制作动态下拉列表,c#,asp.net,dynamic,drop-down-menu,C#,Asp.net,Dynamic,Drop Down Menu,我正在尝试以这种方式制作动态下拉列表: <form id="form1" runat="server"> <asp:DropDownList ID="ddlCategory" runat="server" AutoPostBack="True" onselectedindexchanged="CategoryDropList_SelectedIndexChanged" /> </form> void DropListInit() { Di
下拉列表
:
<form id="form1" runat="server">
<asp:DropDownList ID="ddlCategory" runat="server" AutoPostBack="True"
onselectedindexchanged="CategoryDropList_SelectedIndexChanged" />
</form>
void DropListInit()
{
Dictionary<string, string> dic = new Dictionary<string, string>();
dic.Add("1","apple");
dic.Add("2","banana");
ddlCategory.DataSource = dic;
ddlCategory.DataTextField = "value";
ddlCategory.DataValueField = "key";
ddlCategory.DataBind();
}
protected void Page_LoadComplete(object sender, EventArgs e)
{
DropListInit();
}
protected void CategoryDropList_SelectedIndexChanged(object sender, EventArgs e)
{
ddlCategory.SelectedValue = ddlCategory.SelectedValue;
}
void DropListInit()
{
Dictionary dic=新字典();
dic.添加(“1”、“苹果”);
dic.添加(“2”、“香蕉”);
ddlcontegory.DataSource=dic;
ddlcontegory.DataTextField=“值”;
ddlcontegory.DataValueField=“key”;
ddlcontegory.DataBind();
}
受保护的无效页面加载完成(对象发送方,事件参数e)
{
DropListInit();
}
受保护的无效类别Hydropolist\u SelectedIndexChanged(对象发送方,事件参数e)
{
ddlcontegory.SelectedValue=ddlcontegory.SelectedValue;
}
我发现如果没有这个奇怪的表达式,
ddlcegory.SelectedValue=ddlcegory.SelectedValue那么,这个表达式是什么意思?还是我做错了什么 将液滴指示器移至页面加载
,如下所示:
protected void Page_LoadComplete(object sender, EventArgs e)
{
if (!IsPostBack)
{
DropListInit();
}
}
去掉这个
ddlCategory.SelectedValue = ddlCategory.SelectedValue;
应该没问题