DropDownList控件使用
DropDownList控件与RadioButtonList控件相似。DropDownList表示一组相互排斥的选项。可以通过三种方式添加选项到DropDownList:在声明DropDownList时列出选项(即在HTML代码中或借助属性编辑器添加);直接往DropDownList控件的ListItemCollection集合中添加项(如下例1、列2);绑定DropDownList到数据源(例3)。
例1:
private void Page_Load(object sender, System.EventArgs e)
{ this.DropDownList1.Items.Add("一");
Response.Write(this.DropDownList1.SelectedValue);//等同于this.DropDownList1.SelectedItem.Value
}//此时Value属性同步与Text属性 显示结果为:一 ;SelectedIndex值为0;
例2:protected System.Web.UI.WebControls.DropDownList DropDownList1;
private void Page_Load(object sender, System.EventArgs e)
{ ListItem li =new ListItem();
li.Text="一";
li.Value="1";
this.DropDownList1.Items.Add(li);//或可以采取 this.DropDownList1.Items.Add(new ListItem("一","1"))
Response.Write(this.DropDownList1.SelectedItem.Value);
}/此时Value属性为1,Text属性为一 显示结果为:1 ;SelectedIndex值为0;
例3:
protected System.Web.UI.WebControls.DropDownList ddlShengOld;
string strSql="select sheng,shengid from t_sheng";
SqlDataReader sdr=Auiso.Base.ExecuteSql_sdr(strSql);
this.ddlShengOld.DataSource=sdr;
this.ddlShengOld.DataTextField="sheng";//对应Text
this.ddlShengOld.DataValueField="shengid";//对应Value 不显示出来
this.ddlShengOld.DataBind();
例4:初始化选定某个值的方法
foreach (ListItem li in this.ddlist)
{
if (li.Value=="设定值")
{
li.Selected=true;
}
}
或使用DropDownList1.SelectedIndex = DropDownList1.Items.IndexOf(DropDownList1.Items.FindByText(str1))
例5:实现联动
在该控件的CheckedChanged事件编程,并将AutoPostBack属性设置为True
例6:实现ListBox或DropDownList之间项目转移
用this.ListBox1.SelectedIndex=-1;
this.ListBox1.Items.Add(this.DropDownList1.SelectedItem);
this.DropDownList1.Items.Remove(this.DropDownList1.SelectedItem);
ListBox 可以通过ListSelectionMode 设置多选,默认值为 Single
例1:
private void Page_Load(object sender, System.EventArgs e)
{ this.DropDownList1.Items.Add("一");
Response.Write(this.DropDownList1.SelectedValue);//等同于this.DropDownList1.SelectedItem.Value
}//此时Value属性同步与Text属性 显示结果为:一 ;SelectedIndex值为0;
例2:protected System.Web.UI.WebControls.DropDownList DropDownList1;
private void Page_Load(object sender, System.EventArgs e)
{ ListItem li =new ListItem();
li.Text="一";
li.Value="1";
this.DropDownList1.Items.Add(li);//或可以采取 this.DropDownList1.Items.Add(new ListItem("一","1"))
Response.Write(this.DropDownList1.SelectedItem.Value);
}/此时Value属性为1,Text属性为一 显示结果为:1 ;SelectedIndex值为0;
例3:
protected System.Web.UI.WebControls.DropDownList ddlShengOld;
string strSql="select sheng,shengid from t_sheng";
SqlDataReader sdr=Auiso.Base.ExecuteSql_sdr(strSql);
this.ddlShengOld.DataSource=sdr;
this.ddlShengOld.DataTextField="sheng";//对应Text
this.ddlShengOld.DataValueField="shengid";//对应Value 不显示出来
this.ddlShengOld.DataBind();
例4:初始化选定某个值的方法
foreach (ListItem li in this.ddlist)
{
if (li.Value=="设定值")
{
li.Selected=true;
}
}
或使用DropDownList1.SelectedIndex = DropDownList1.Items.IndexOf(DropDownList1.Items.FindByText(str1))
例5:实现联动
在该控件的CheckedChanged事件编程,并将AutoPostBack属性设置为True
例6:实现ListBox或DropDownList之间项目转移
用this.ListBox1.SelectedIndex=-1;
this.ListBox1.Items.Add(this.DropDownList1.SelectedItem);
this.DropDownList1.Items.Remove(this.DropDownList1.SelectedItem);
ListBox 可以通过ListSelectionMode 设置多选,默认值为 Single