[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";
ddlItems.DataBind();
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, F; d4 X5 G; x( f6 p% T- L$ X  V5 Z) ?《二》添加默认项“请选择”
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方法1
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绑定后添加
ListItem lt = new ListItem();
lt.Text = "请选择";
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lt.Selected = true;
3 @  F- U9 e, ^9 B0 }ddl.Items.Add(lt);

放到databind()之后
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/ }. V  d5 {8 u9 a方法2
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绑定以后添加下面代码：
+ [% A5 C: p( ]( k7 oListItem it = new ListItem("请选择", "0");
ddl.Items.Insert(0,it);

1 j  E  h: @# X$ m; S《三》绑定后指定第一项
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; I0 _/ ^/ I% \/ Q. U& ]ddlItems.DataSource = voe.SelectItems();
( I3 o4 n: n: VddlItems.DataTextField = "VoteItem";
6 J* p9 U6 |! p# H; n5 k" i  N, k1 qddlItems.DataValueField = "VoteId";
ddlItems.DataBind();
string str="你想要的文本";
int index = this.ddl.Items.IndexOf(this.ddl.Items.FindByText(str));
: y2 p/ h% A3 r4 H0 u, E) oddl.SelectedIndex = index;
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# r* u0 L2 r5 m《三》绑定后指定第一项
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* l, R7 }! L2 s0 y. j' P; |ddlItems.DataSource = voe.SelectItems();
ddlItems.DataTextField = "VoteItem";
ddlItems.DataValueField = "VoteId";
ddlItems.DataBind();
* R  e' F$ W8 s5 }string vID = Request.QueryString["id"];
0 z  i. M1 X# @$ D2 M# q( {ddl.SelectedValue= vID;