This sound simple but开发者_开发知识库 it not that much.
I want to order a List based on one of the properties of T, which is double type.
If you know the propertyname before compilation:
myList = myList.OrderBy(a=>a.propertyName).ToList();
or
myList = (from m in myList order by m.propertyName).ToList();
If you don't have the property at compile time (e.g. dynamic sorting in a grid or something); try the following extension methods:
static class OrderByExtender
{
public static IOrderedEnumerable<T> OrderBy<T>(this IEnumerable<T> collection, string key, string direction)
{
LambdaExpression sortLambda = BuildLambda<T>(key);
if(direction.ToUpper() == "ASC")
return collection.OrderBy((Func<T, object>)sortLambda.Compile());
else
return collection.OrderByDescending((Func<T, object>)sortLambda.Compile());
}
public static IOrderedEnumerable<T> ThenBy<T>(this IOrderedEnumerable<T> collection, string key, string direction)
{
LambdaExpression sortLambda = BuildLambda<T>(key);
if (direction.ToUpper() == "ASC")
return collection.ThenBy((Func<T, object>)sortLambda.Compile());
else
return collection.ThenByDescending((Func<T, object>)sortLambda.Compile());
}
private static LambdaExpression BuildLambda<T>(string key)
{
ParameterExpression TParameterExpression = Expression.Parameter(typeof(T), "p");
LambdaExpression sortLambda = Expression.Lambda(Expression.Convert(Expression.Property(TParameterExpression, key), typeof(object)), TParameterExpression);
return sortLambda;
}
}
Then order like
myList = myList.OrderBy("propertyName", "ASC").ToList();
var list = (from t in list
orderby t.doubleVal).ToList();
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