C# 将项目插入dropdownlist
我想根据dropdownlist1(来自表1)的所选项目显示我的dropdownlist2(来自表2)中的项目 在下面,我只是尝试根据dropdownlist1中的值从表2中选择lang列值((只是插入dropdownlist1)) 那是正确的代码吗C# 将项目插入dropdownlist,c#,asp.net,data-binding,C#,Asp.net,Data Binding,我想根据dropdownlist1(来自表1)的所选项目显示我的dropdownlist2(来自表2)中的项目 在下面,我只是尝试根据dropdownlist1中的值从表2中选择lang列值((只是插入dropdownlist1)) 那是正确的代码吗 SqlDataAdapter da = new SqlDataAdapter( "Select lang from table2 whereheatre=@d",connect.con()); da.SelectCom
SqlDataAdapter da = new SqlDataAdapter(
"Select lang from table2 whereheatre=@d",connect.con());
da.SelectCommand.Parameters.AddWithValue("@d", DropDownList1.SelectedItem.Text);
DataSet ds=new DataSet();
da.Fill(ds,"l1");
DropDownList2.Items.Add(ds);
是否有其他方法可以这样做…?要将新值添加到现有的dropdownlist中,您应该手动添加新行:
foreach (DataRow dr in ds.Tables[0].Rows)
{
DropDownList2.Items.Add(new ListItem(dr["TextField"].ToString(), dr["ValueField"].ToString()));
}
或者,在将它们绑定到dropdownlist之前,您应该先将它们绑定到dropdownlist。如果您只想用刚才提到的查询后返回的值填充DropDownList2,您应该将其数据绑定
SqlDataAdapter da = new SqlDataAdapter(
"Select lang from table2 whereheatre=@d",connect.con());
da.SelectCommand.Parameters.AddWithValue("@d", DropDownList1.SelectedItem.Text);
DataSet ds=new DataSet();
DropDownList2.DataSource = ds;
DropDownList2.DataTextField = "lang";
DataBind();
此外,还可以通过这种方式将值字段添加到下拉列表中(但必须修改sql查询,使其返回2列):
祝你好运 尝试在dropdownlist 1上连接SelectedIndexChanged事件,然后绑定dropdownlist 2。我假设您正在使用Asp.net 这将出现在您的aspx页面中:
<asp:DropDownList ID="ddlOne"runat="server" OnSelectedIndexChanged="ddlOne_OnSelectedIndexChanged"
AutoPostBack="true" />
<asp:DropDownList ID="ddlTwo"runat="server" DataTextField="lang" DataValueField="colId" />
<asp:DropDownList ID="ddlOne"runat="server" OnSelectedIndexChanged="ddlOne_OnSelectedIndexChanged"
AutoPostBack="true" />
<asp:DropDownList ID="ddlTwo"runat="server" DataTextField="lang" DataValueField="colId" />
protected void ddlOne_OnSelectedIndexChanged(object sender, EventArgs e)
{
// Go get your data here then bind to it..
ddlTwo.DataSource = "Whatever datasource you want here";
ddlTwo.DataBind();
}