C # query dynamic OrderBy by using linq,

C # query dynamic OrderBy by using linq,

GroupList is a collection of raw data, List <T>

SortOrder is the sorting type, desc or asc

SortName is the name of the sorting attribute.

1. Use reflection.

Private static object GetPropertyValue (object obj, string property) {System. reflection. propertyInfo propertyInfo = obj. getType (). getProperty (property); return propertyInfo. getValue (obj, null);} var resultList = sortOrder = "desc "? GroupList. orderByDescending (p => GetPropertyValue (p, sortName): groupList. orderBy (p => GetPropertyValue (p, sortName); // use the following method: // var resultList1 = from p in groupList orderby GetPropertyValue (p, m. sortName) select p; if (sortOrder = "desc") resultList1 = from p in groupList orderby GetPropertyValue (p, sortName) descending select p;

2. Call AsQueryable ()

Convert Generic System. Collections. Generic. IEnumerable <T> to Generic System. Linq. IQueryable <T>.

var groupQueryList = groupList.AsQueryable();//herevar tmpList = groupQueryList.OrderBy(sortName, sortOrder);

The following extension method is required:

    public static IOrderedQueryable<T> OrderByDescending<T>(this IQueryable<T> source, string property)    {        return ApplyOrder<T>(source, property, "OrderByDescending");    }    public static IOrderedQueryable<T> ThenBy<T>(this IOrderedQueryable<T> source, string property)    {        return ApplyOrder<T>(source, property, "ThenBy");    }    public static IOrderedQueryable<T> ThenByDescending<T>(this IOrderedQueryable<T> source, string property)    {        return ApplyOrder<T>(source, property, "ThenByDescending");    }    static IOrderedQueryable<T> ApplyOrder<T>(IQueryable<T> source, string property, string methodName) {        string[] props = property.Split('.');        Type type = typeof(T);        ParameterExpression arg = Expression.Parameter(type, "x");        Expression expr = arg;        foreach(string prop in props) {            // use reflection (not ComponentModel) to mirror LINQ            PropertyInfo pi = type.GetProperty(prop);            expr = Expression.Property(expr, pi);            type = pi.PropertyType;        }        Type delegateType = typeof(Func<,>).MakeGenericType(typeof(T), type);        LambdaExpression lambda = Expression.Lambda(delegateType, expr, arg);        object result = typeof(Queryable).GetMethods().Single(                method => method.Name == methodName                        && method.IsGenericMethodDefinition                        && method.GetGenericArguments().Length == 2                        && method.GetParameters().Length == 2)                .MakeGenericMethod(typeof(T), type)                .Invoke(null, new object[] {source, lambda});        return (IOrderedQueryable<T>)result;   } 

 

Reference: http://stackoverflow.com/questions/41244/dynamic-linq-orderby-on-ienumerablet#41262