c# - Error when passing data to my view? -

i creating website in asp.net mvc. working on page feature dropdowns created based upon users statistics. this, have set @html.dropdownlistfor uses increment system fulfill randomly generated system. in post method, can dropdown values calling rightsfor_1, , on shown below.

my problem when run program, error stated below occurring on @html.dropdownlistfor line of code.

snippit of code in view:

     @for(int = 0; < model.labpermdata.count(); i++)         {         <div class="row">             <div class="col-md-2">                 <b>@html.displayfor(m => m.labpermdata[i].lab.labname)</b>              </div>             <div class="col-md-2">                 @html.dropdownlistfor(m=>"rightsfor_"+m.labpermdata[i].lab.labname, model.lpdd, "select one")             </div>             <div class="col-md-8">             </div>         </div>         } 

i trying access values in controller using this:

        var value1 = request["rightsfor_0"];         var value2 = request["rightsfor_1"];         var value3 = request["rightsfor_2"];         //... , on 

error received:

templates can used field access, property access, single-dimension array index, or single-parameter custom indexer expressions.

you can't append strings in lambda expression that. add name attribute dropdown uses incremented name instead.

@html.dropdownlistfor(m=>m.labpermdata[i].lab.labname, model.lpdd, "select one", new { name = "rightsfor_" + m.labpermdata[i].lab.labname }) 

something else may able create string before putting in lambda.

@{ string rightsfor = "rightsfor_" + m.labpermdata[i].lab.labname; } @html.dropdownlistfor(m=>rightsfor, model.lpdd, "select one")