[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();
, J1 C9 E& J# w' H& DddlItems.DataTextField = "VoteItem";
ddlItems.DataValueField = "VoteId";
. r& k1 w/ X& P" F3 |5 H! K+ k: DddlItems.DataBind();

《二》添加默认项“请选择”

方法1

绑定后添加
ListItem lt = new ListItem();
* T1 \* d5 E2 a6 u" _+ O, r/ ]4 n$ vlt.Text = "请选择";
! t3 I+ W% U% c6 S/ U) d4 Mlt.Value = "00";
+ N2 P# y" o# M# a+ s% Ylt.Selected = true;
+ R2 m4 K1 n2 D9 w/ c1 l/ cddl.Items.Add(lt);
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放到databind()之后
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+ V* u# W  K, H/ l$ [& o方法2
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2 X2 T- U8 x# g$ ?2 h1 k绑定以后添加下面代码：
ListItem it = new ListItem("请选择", "0");
ddl.Items.Insert(0,it);

) ^- E: D3 S7 W8 W" [) A《三》绑定后指定第一项
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ddlItems.DataSource = voe.SelectItems();
) r  _/ y$ J) o9 p8 FddlItems.DataTextField = "VoteItem";
5 J+ c6 Y: i; a$ F/ a& T# D5 _ddlItems.DataValueField = "VoteId";
7 C. K! M! N: s& A  r- a5 G6 ZddlItems.DataBind();
" j$ a! G/ E6 ?2 `0 z. T# ^  lstring str="你想要的文本";
' T/ d9 b5 B) s$ _int index = this.ddl.Items.IndexOf(this.ddl.Items.FindByText(str));
ddl.SelectedIndex = index;

《三》绑定后指定第一项
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* w" W7 n0 u5 w4 B* \0 a: d% Q- fddlItems.DataSource = voe.SelectItems();
ddlItems.DataTextField = "VoteItem";
! q9 K1 a- [; B$ h8 b9 L5 P6 u9 R3 Z  |ddlItems.DataValueField = "VoteId";
ddlItems.DataBind();
2 Q6 @  x8 z8 ]- ~. L5 k9 B3 A9 ^string vID = Request.QueryString["id"];
, X, F" m. u) E2 x  Tddl.SelectedValue= vID;