[转]dropdownlist动态绑定数据方法 添加默认项“请选择”

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《一》动态绑定方法
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ddlItems.DataSource = voe.SelectItems();
ddlItems.DataTextField = "VoteItem";
ddlItems.DataValueField = "VoteId";
* Q* u$ }, h# g& b( p  ~ddlItems.DataBind();
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; g' {5 U( D* }《二》添加默认项“请选择”
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" k1 `4 _, a  N& b$ F方法1

4 i5 X& m% b9 F6 r- m( D# q绑定后添加
ListItem lt = new ListItem();
lt.Text = "请选择";
lt.Value = "00";
lt.Selected = true;
6 h7 b: Z( k& U# lddl.Items.Add(lt);

, o$ ^, |% L* L0 z放到databind()之后
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方法2

绑定以后添加下面代码：
ListItem it = new ListItem("请选择", "0");
& [5 h) _" l" j' D- Sddl.Items.Insert(0,it);
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《三》绑定后指定第一项
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ddlItems.DataSource = voe.SelectItems();
: D# s# Q, H/ R  z/ TddlItems.DataTextField = "VoteItem";
ddlItems.DataValueField = "VoteId";
8 G7 P. P% y& a4 T& ^8 g! T# fddlItems.DataBind();
string str="你想要的文本";
int index = this.ddl.Items.IndexOf(this.ddl.Items.FindByText(str));
ddl.SelectedIndex = index;
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2 R+ Y% R) @' \1 c《三》绑定后指定第一项

) d, I4 e- G5 B7 M; a. d: [! {ddlItems.DataSource = voe.SelectItems();
ddlItems.DataTextField = "VoteItem";
ddlItems.DataValueField = "VoteId";
" {% V7 f, e8 X' r7 }7 ^& fddlItems.DataBind();
string vID = Request.QueryString["id"];
& W1 w. \% _* O( Mddl.SelectedValue= vID;