[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

ddlItems.DataSource = voe.SelectItems();
ddlItems.DataTextField = "VoteItem";
& v3 m, l4 B/ m3 Y  W5 G+ c+ x: u$ CddlItems.DataValueField = "VoteId";
ddlItems.DataBind();

8 T; ^2 o( p8 F& d! I8 x《二》添加默认项“请选择”
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' d' G% T& T9 Z- w+ Y+ F/ a4 f方法1
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绑定后添加
ListItem lt = new ListItem();
7 d$ a, k2 l7 @8 Nlt.Text = "请选择";
lt.Value = "00";
lt.Selected = true;
, F# X# l# j, a4 O- Sddl.Items.Add(lt);

* ~+ X% _- J! C放到databind()之后

方法2

% E- ?- g, N+ x7 z1 m1 U/ H5 Z绑定以后添加下面代码：
( m" d) E8 u) YListItem it = new ListItem("请选择", "0");
ddl.Items.Insert(0,it);

9 l5 M3 d6 d9 X0 \* q《三》绑定后指定第一项
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ddlItems.DataSource = voe.SelectItems();
7 B" j% Z  Z5 H6 mddlItems.DataTextField = "VoteItem";
ddlItems.DataValueField = "VoteId";
ddlItems.DataBind();
string str="你想要的文本";
; @5 U& F3 X# {  a. E9 eint index = this.ddl.Items.IndexOf(this.ddl.Items.FindByText(str));
1 {& X( `, b' z3 d* h, Oddl.SelectedIndex = index;
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# |( J# K) h% y4 W+ I( K《三》绑定后指定第一项

ddlItems.DataSource = voe.SelectItems();
& x: ^! N/ v9 ^* i  }# }  addlItems.DataTextField = "VoteItem";
: V% R( g, C' Q0 F  G( BddlItems.DataValueField = "VoteId";
ddlItems.DataBind();
string vID = Request.QueryString["id"];
8 n+ }9 Y) }- z4 tddl.SelectedValue= vID;