http://www.cnblogs.com/kay/archive/2007/01/27/632226.html
DropDownList数据绑定第一项为空
我们在进行数据绑定时通常把一个表的某个字段绑定到DropDownList中,我们以pubs库的jobs表为例子,我们在显示时显示job_desc字段,values值绑定job_id字段。
方法一:
使用属性设置,我们在DropDownList的items的属性中添加一列为空行,然后更改AppandBataBoundItems属性为ture.
绑定代码:
绑定代码
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SqlConnection conn = new SqlConnection("server=.;uid=sa;database=pubs");
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SqlDataAdapter dap = new SqlDataAdapter("select * from jobs", conn);
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DataTable dt = new DataTable();
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dap.Fill(dt);
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DropDownList1.Items.Clear();
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DropDownList1.DataSource = dt;
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DropDownList1.DataTextField = "job_desc";
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DropDownList1.DataValueField = "job_id";
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DropDownList1.DataBind();
方法一:
使用属性设置,我们在DropDownList的items的属性中添加一列为空行,然后更改AppandBataBoundItems属性为ture.
绑定代码:


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这样就可以了。
方法二:
使用代码:
方法二:
使用代码:
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SqlConnection conn
=
new
SqlConnection(
"
server=.;uid=sa;database=pubs
"
);
3
SqlDataAdapter dap
=
new
SqlDataAdapter(
"
select * from jobs
"
, conn);
4
DataTable dt
=
new
DataTable();
5
dap.Fill(dt);
6
DropDownList1.Items.Clear();
7
DropDownList1.DataSource
=
dt;
8
DropDownList1.DataTextField
=
"
job_desc
"
;
9
DropDownList1.DataValueField
=
"
job_id
"
;
10
DropDownList1.DataBind();
11
DropDownList1.Items.Insert(
0
,
new
ListItem(
""
,
""
));
//
插入空项,此举必须放到数据绑定之后

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_____________________________________________________________________________________________________
两种绑定DropDownList数据源的方式
第一种: (更快)
…………………………………………
DataSet ds= new DataSet();
ds = cls2.SelectOle();
DropDownList1.DataSource = ds.Tables["My"].DefaultView;
DropDownList1.DataTextField = "dep_Name";
DropDownList1.DataValueField = "dep_Id";
DropDownList1.DataBind();
第二种: (更灵活)
DataSet set1= new DataSet();
set1 = cls2.SelectOle();
for (int num1 = 0; num1 < set1.Tables["My"].Rows.Count; num1++)
{
DropDownList1.Items.Add(set1.Tables["My"].Rows[num1][1].ToString());
}
<asp:DropDownList id="DropDownList1" DataValueField="dep_Id" DataTextField="dep_Name" runat="server"></asp:DropDownList>
…………………………………………
DataSet ds= new DataSet();
ds = cls2.SelectOle();
DropDownList1.DataSource = ds.Tables["My"].DefaultView;
DropDownList1.DataTextField = "dep_Name";
DropDownList1.DataValueField = "dep_Id";
DropDownList1.DataBind();
第二种: (更灵活)
DataSet set1= new DataSet();
set1 = cls2.SelectOle();
for (int num1 = 0; num1 < set1.Tables["My"].Rows.Count; num1++)
{
DropDownList1.Items.Add(set1.Tables["My"].Rows[num1][1].ToString());
}
<asp:DropDownList id="DropDownList1" DataValueField="dep_Id" DataTextField="dep_Name" runat="server"></asp:DropDownList>
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1.连接数据库
2.命令
3.分配数据源
4.填写,绑定!