DropDownList绑定及修改

一、DropDownList:
1、选项值保存到数据库：
Hashtable ht=new Hashtable();//这里用Hashtable
ht.Add("字段名"，DropDownListID.SelectedItem.Text.ToString());//保存选项Text
ht.Add("字段名"，DropDownListID.SelectedItem.Value.ToString());//保存选项Value

2、选项值由数据库绑定到DropDownList：
首先DropDownListID.ClearSelection();//清除选项
DropDownListID.Items.FindByText(dr["字段名"].ToString()).Selected = true;//选项Text
DropDownListID.Items.FindByValue(dr["字段名"].ToString()).Selected = true;//选项Value

二、RadioButtonList:
1、选项值保存到数据库(同DropDownList)：
Hashtable ht=new Hashtable();//这里用Hashtable
ht.Add("字段名"，RadioButtonListID.SelectedItem.Text.ToString());//保存选项Text
ht.Add("字段名"，RadioButtonListID.SelectedItem.Value.ToString());//保存选项Value

2、选项值由数据库绑定到RadioButtonList
string SelectItem = dr["字段名"].ToString();//将数据库中的选项值从DataRow中读出赋给变量SelectItem
for (int i = 0; i < RadioButtonListID.Items.Count; i++)
{//用for循环判断那项被选种
if (RadioButtonListID.Items[i].Text == SelectItem)RadioButtonListID.Items[i].Selected = true;
}

三、CheckBoxList:
1、选项值保存到数据库
string SelectItem = "";//声明一个变量来接受选项
for (int i = 0; i < CheckBoxListID.Items.Count; i++)
{//用for循环将所有选项用","隔开连接起来
if (CheckBoxListID.Items[i].Selected)
{
SelectItem = SelectItem + CheckBoxListID.Items[i].Value + ",";//选项后加","隔开
}
}
ht.Add("字段名",SelectItem.ToString());

2、选项值由数据库绑定到CheckBoxList
string SelectItem = dr["字段名"].ToString();
string[] arrStr = SelectItem.Split(',');//字段是以","隔开
foreach (string str in arrStr)
{
for (int i = 0; i <CheckBoxListID.Items.Count; i++)
{
if (this.CheckBoxListID.Items[i].Value == str)
{
this.CheckBoxListID.Items[i].Selected = true;
}
}
}
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1.把数据绑定到CheckBoxList中

protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
SqlConnection con = GetDBCon.GetCon();
con.Open();
SqlDataAdapter sda = new SqlDataAdapter("select * from admin", con);
DataSet ds = new DataSet();
sda.Fill(ds,"admin");
this.CheckBoxList1.DataSource = ds.Tables[0];
this.CheckBoxList1.DataTextField = "username";//绑定的字段名
this.CheckBoxList1.DataValueField = "userid";//绑定的值
this.CheckBoxList1.DataBind();

}
}

2.循环读取出来

protected void CheckBoxList1_SelectedIndexChanged(object sender, EventArgs e)
{
this.Lab2.Text = "";
for (int i = 0; i < CheckBoxList1.Items.Count; i++)
{
if (this.CheckBoxList1.Items[i].Selected)
{
this.Lab2.Text = this.Lab2.Text+CheckBoxList1.Items[i].Text+".";
}
}
}