C # Extended LINQ's Order by function supports specifying column names by string and supporting multiple columns

This paper draws on 68523451.

Converting a string to an order by LINQ can greatly reduce duplication of effort, but how do you convert multiple fields to the () and ThenBy () expressions? You can refer to the following code:

 Public StaticIorderedqueryable<t> orderby<t> ( ThisIqueryable<t> Q,stringcondition) {            string[] conditions = condition. Split (','); if(Conditions. length==0)            {                return(iorderedqueryable<t>) Q; } iorderedqueryable<T> res =NULL;  for(inti =0; I < conditions. Length; i++)            {                string[] strings = Conditions[i]. Split (" "); varFieldName = strings[0]; varDirection = strings[1]; varparam = Expression.parameter (typeof(T),"P"); varProp =expression.property (param, fieldName); varExp =expression.lambda (prop, param); stringmethod; if(i==0) {method= direction. ToLower () = ="ASC"?" by":"orderbydescending"; }                Else{method= direction. ToLower () = ="ASC"?"ThenBy":"thenbydescending"; } type[] Types={q.elementtype, exp.                Body.type}; varMCE = i==0? Expression.call (typeof(queryable), method, types, Q.expression, exp): Expression.call (typeof(queryable), method, types, res.                Expression, exp); if(Conditions. Length = =1)                {                    return(iorderedqueryable<t>) q.provider.createquery<t>(MCE); } Res= i = =0? (iorderedqueryable<t>) q.provider.createquery<t> (MCE): (iorderedqueryable<t>) Res. Provider.createquery<t>(MCE); }            returnRes; }

The IQueryable object calls the order by method, passing in the "Id desc,age desc" format string to enable multi-column sorting.

C # Extended LINQ's Order by function supports specifying column names by string and supporting multiple columns