asp.net中根据数据库中数据自动设置dropdownlist中选中的值

//前台

<asp:DropDownList ID="ddlmodel" runat="server" AutoPostBack="True"

onselectedindexchanged="ddlmodel_SelectedIndexChanged">

<asp:ListItem Value="2">两</asp:ListItem>

<asp:ListItem Value="3" Selected="True">三</asp:ListItem>

</asp:DropDownList>

//后台

SqlSen ss = new SqlSen();//调用APP_CODE中函数

string text1, text2, text3, size1, size2, size3, width1, width2, width3;

ss.SELIDData(id, out text1, out text2, out text3, out size1, out size2, out size3, out width1, out width2, out width3);

this.t1.Text = text1;

this.t2.Text = text2;

this.t3.Text = text3;

if (this.t3.Text.Equals(""))

{

ddlmodel.SelectedValue = "2";

this.t3.Enabled = false;

}

if (this.t3.Text != "")

{

ddlmodel.SelectedValue = "3";

this.t3.Enabled = true;

}

ddlSize1.SelectedValue = ddlSize1.Items.FindByValue(size1).ToString();//将数据库中的数据调给dropdownlist中,使其有自动选择效果

ddlSize2.SelectedValue = ddlSize2.Items.FindByValue(size2).ToString();

ddlSize3.SelectedValue = ddlSize3.Items.FindByValue(size3).ToString();