怎么执行下面的语句
else if(DropDownList1.SelectedItem.Text!="所有类别" && DropDownList2.SelectedItem.Text!="所有品牌" && TextBox1.Text=="")
{
string s1=DropDownList1.SelectedItem.Text;
string s2=DropDownList2.SelectedItem.Text;
Response.Redirect("jjcpss.aspx?IDL='"+s1+"' && IDP='"+s2+"'");
}
在page_load中写
if(!IsPostBack)
{
if((Request.QueryString["IDL"]) ==null && (Request.QueryString["IDP"]) == null && (Request.QueryString["IDT"]) == null)
{
Bind();
}
else if(Request.QueryString["IDL"] !=null && Request.QueryString["IDP"] == null && Request.QueryString["IDT"] == null)
{
}
else if((Request.QueryString["IDL"]) ==null && (Request.QueryString["IDP"]) != null && (Request.QueryString["IDT"]) == null)
{
}
else if((Request.QueryString["IDL"]) !=null && (Request.QueryString["IDP"]) != null && (Request.QueryString["IDT"]) == null)
{
}
}
当触发事件时它始终执行
else if(Request.QueryString["IDL"] !=null && Request.QueryString["IDP"] == null && Request.QueryString["IDT"] == null)
{
}
不执行else if((Request.QueryString["IDL"]) !=null && (Request.QueryString["IDP"]) != null && (Request.QueryString["IDT"]) == null)
{
}有没有办法解决