[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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0 L& J3 q' C3 Y( sddlItems.DataSource = voe.SelectItems();
ddlItems.DataTextField = "VoteItem";
ddlItems.DataValueField = "VoteId";
. A; V, t- H; |/ v2 ?' L# hddlItems.DataBind();

9 F+ e+ C$ i4 F  o. y《二》添加默认项“请选择”
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. J" R8 ~  k2 W! g7 s8 I6 o0 E: }方法1
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% b0 T1 E3 Q* K2 r; H绑定后添加
ListItem lt = new ListItem();
lt.Text = "请选择";
lt.Value = "00";
lt.Selected = true;
& y, L8 r$ U! P" f  z2 Jddl.Items.Add(lt);

6 k4 C3 a  B' y放到databind()之后
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方法2
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- ~3 m) S7 p( P1 \7 A  Q7 U绑定以后添加下面代码：
4 n; n  U1 d, d+ eListItem it = new ListItem("请选择", "0");
ddl.Items.Insert(0,it);

《三》绑定后指定第一项

# |* ~2 y+ h3 |" n/ ?  j" |ddlItems.DataSource = voe.SelectItems();
% [/ A& D% S& [  V3 Q% XddlItems.DataTextField = "VoteItem";
ddlItems.DataValueField = "VoteId";
/ y  S1 y  g3 U. {1 c& SddlItems.DataBind();
string str="你想要的文本";
# i! f, T. g+ O$ R. C$ k5 Vint index = this.ddl.Items.IndexOf(this.ddl.Items.FindByText(str));
ddl.SelectedIndex = index;

" J6 H! K% I+ g& l7 T' g3 N9 t+ u《三》绑定后指定第一项

ddlItems.DataSource = voe.SelectItems();
ddlItems.DataTextField = "VoteItem";
6 N5 T0 C) R% ^5 G$ SddlItems.DataValueField = "VoteId";
ddlItems.DataBind();
string vID = Request.QueryString["id"];
ddl.SelectedValue= vID;