See 使用 LINQ 处理 GridView.OnSorting() 并动态创建排序表达式 http://www.codeproject.com/Articles/246361/Handle-GridView-OnSorting-using-LINQ
public static class SortExpressionBuilder<T>
{
private static IDictionary<SortDirection, ISortExpression> directions = new Dictionary<SortDirection, ISortExpression>
{
{ SortDirection.Ascending, new OrderByAscendingSortExpression() },
{ SortDirection.Descending, new OrderByDescendingSortExpression() }
};
interface ISortExpression
{
Func<IEnumerable<T>, Func<T, object>, IEnumerable<T>> GetExpression();
}
class OrderByAscendingSortExpression : ISortExpression
{
public Func<IEnumerable<T>, Func<T, object>, IEnumerable<T>> GetExpression()
{
return (c, f) => c.OrderBy(f);
}
}
class OrderByDescendingSortExpression : ISortExpression
{
public Func<IEnumerable<T>, Func<T, object>, IEnumerable<T>> GetExpression()
{
return (c, f) => c.OrderByDescending(f);
}
}
public static Func<IEnumerable<T>, Func<T, object>, IEnumerable<T>> CreateExpression(SortDirection direction)
{
return directions[direction].GetExpression();
}
}
public static IEnumerable<T> OrderBy<T>(this IEnumerable<T> collection, string columnName, SortDirection direction)
{
ParameterExpression param = Expression.Parameter(typeof(T), "x"); // x
Expression property = Expression.Property(param, columnName); // x.ColumnName
Func<T, object> func = Expression.Lambda<Func<T, object>>( // x => x.ColumnName
Expression.Convert(Expression.Property(param, columnName),
typeof(object)), param
).Compile();
Func<IEnumerable<T>, Func<T, object>, IEnumerable<T>> expression = SortExpressionBuilder<T>.CreateExpression(direction);
IEnumerable<T> sorted = expression(collection, func);
return sorted;
}
以及底部的链接:
- 使用 Lambda/Linq to 对象对列表进行排序 https://stackoverflow.com/questions/722868/sorting-a-list-using-lambda-linq-to-objects
- GridView 排序:SortDirection 始终升序 https://stackoverflow.com/questions/250037/gridview-sorting-sortdirection-always-ascending