如何使用 generics 和 Linq 扩展方法过滤列表？

Question

I'm trying to write a generic Filter extension method for a system, such that I can call filter on any List and pass in a Dictionary of field names and their values to filter on.

I currently have a method for each type in my system, but I'm trying to consolidate to one method.

Here is what I have so far...simplified so it's only text searching:

public static List<T> Filter<T>(this List<T> model, string json)
    {
        JavaScriptSerializer ser = new JavaScriptSerializer();
        Dictionary<string, object> searchFields = (Dictionary<string, object>)ser.DeserializeObject(json);

        foreach (var key in searchFields.Keys)
        {               
            // How do I perform the search?               
        }

        return model;
    }

My current filter is a switch statement over each key and checking each field as follows:

switch(key) 
{
    case "Description":
        list = list.Where(x => x.Description.ToLower().Contains(searchFields[key].ToString().ToLower())).ToList();
                    break;
}

How do I access the property on the generic object to filter it? I assume I need reflection somehow, but I don't know the syntax.

I'm looking for something like:

list = list.where(listobject.getField(key).contains(value))

Is this possible? Thanks in advance for your help!

Answer 1

try something like that inside your foreach loop

 model.Where(m => typeof(T).GetProperty(key).GetValue(m, null)==searchFields[key]);

Answer 2

foreach (var key in searchFields.Keys)
{               
    model.Where(m => typeof(T).GetProperty(key).GetValue(m, null).Equals(SearchFields[key], StringComparison.OrdianlIgnoreCase);         
}

return model.ToList();