c# - The best overloaded method match for 'double.TryParse(string, out double)' has some invalid arguments -

i did search , didn't find answer question. if it's been asked, i'd appreciate finding it.

i'm bit new coding , i'm trying convert program vb c#.

here original vb code:

for each grpkey in groups.keys.toarray   dim grp = groups(grpkey)   if grp.smartkitparameters.count > 0     dim partnameparam = getparametervalue(grp.smartkitparameters, "%smartkitname%", "")     dim maintcodeparam = getparametervalue(grp.smartkitparameters, "%maintcode%", "p")     dim divisioncodeparam = getparametervalue(grp.smartkitparameters, "%divisioncode%", "w")     dim quantityparam double     double.tryparse(getparametervalue(grp.smartkitparameters, "%quantity%", "0"), quantityparam)     dim smkt new part     {       .partid = allparts.values.max(function(p) p.partid) + 1,       .dpltype = grp.parts.values.first.dpltype,       .plane = grp.parts.values.first.plane,       .quantity = quantityparam,       .maintcode = maintcodeparam,       .partnumber = partnameparam,       .plant = divisioncodeparam,     }     dim parentgrp = getgroup(groups, smkt.dpltype, smkt.plane, "(default group)")     parentgrp.parts.add(smkt.partid, smkt)      allparts.add(smkt.partid, smkt)      groups.remove(grpkey)   end if    using specdimscmd new oledbcommand("select * dplspecialdimensions;", conn)     using rdr = specdimscmd.executereader       while rdr.read         dim partid = rdr.getinteger("partid", 0)         if allparts.containskey(partid)               allparts(partid).specialdimensions.add(new specialdimension               {                 .partid = partid,                 .specdimid = rdr.getinteger("specdimid", 0),                 .maintcode = rdr.getstring("maintcode", ""),                 .specialtype = rdr.getstring("specialtype", ""),                 .specialdim = rdr.getsingle("specialdim", 0.0)               })         end if       end while     end using   end using next 

here i've done convert c# code:

1  foreach (string grpkey_loopvariable in groups.keys.toarray) 2  { 3    if (grp.smartkitparameters.count > 0) 4    { 5      string partnameparam = getparametervalue(grp.smartkitparameters, "%smartkitname%", ""); 6      string maintcodeparam = getparametervalue(grp.smartkitparameters, "%maintcode%", "p"); 7      string divisioncodeparam = getparametervalue(grp.smartkitparameters, "%divisioncode%", "w"); 8      double quantityparam = 0; 9      string quantityparamstring = getparametervalue(grp.smartkitparameters, "%quantity%", "0.0"); 10     double.tryparse(quantityparamstring, quantityparam); 11 12     part smkt = new part 13     { 14       partid = allparts.values.max(p => p.partid) + 1, 15       dpltype = grp.parts.values.first().dpltype, 16       plane = grp.parts.values.first().plane, 17       quantity = quantityparam, 18       maintcode = maintcodeparam, 19       partnumber = partnameparam, 20       plant = divisioncodeparam, 21     }; 22 23   dynamic parentgrp = getgroup(groups, smkt.dpltype, smkt.plane, "(default group)"); 24   parentgrp.parts.add(smkt.partid, smkt); 25   26   allparts.add(smkt.partid, smkt); 27 28   groups.remove(grpkey); 29 } 30 31 using (oledbcommand specdimscmd = new oledbcommand("select * dplspecialdimensions;", conn)) 32 { 33   using (oledbdatareader rdr = specdimscmd.executereader()) 34   { 35     while (rdr.read()) 36     { 37       dynamic partid = getinteger(rdr idatareader, "partid", 0); 38       if (allparts.containskey(partid)) 39       { 40         allparts[partid].specialdimensions.add(new specialdimension 41         { 42           partid = partid, 43           specdimid = getinteger(rdr idatareader, "specdimid", 0), 44           maintcode = getstring(rdr idatareader, "maintcode", ""), 45           specialtype = getstring(rdr idatareader, "specialtype", ""), 46           specialdim = getsingle(rdr idatareader, "specialdim", 0) 47          }); 48        } 49      } 50    } 51  } 52}  

at line 10 in c# code, getting error:

the best overloaded method match 'double.tryparse(string, out double)' has invalid arguments

this doesn't make sense me since arguments correct type (string , double). invalid arguments in other way?

doubleparam out parameter, should explictly tell so:

double.tryparse(quantityparamstring, out quantityparam);