Generate EF orderby expression by string

Question

I want to generate expression by string parameter,some code like:

private Expression> Generate(string orderby)
{
    switch (orderb         


        

Answer 1

You could try converting the Generate method in a generic method:

private Expression> Generate(string orderby)
{
     switch (orderby)
     {
        case "Time":  
          return t => t.Time;
        case "Money":
          return t => t.RewardMoney;
        default:
         return t => t.Id;
     }
}

So, if you call this method, you need to specify the type of the property that you want to order by:

_context.Items.OrderBy(Generate("Money"));

Now remember that TResult can only be a primitive type or enumeration type.