Reputation: 26332
I use following code for sorting list in application and it is working fine.
public static class OrderByHelper
{
public static IOrderedQueryable<T> OrderBy<T>(this IQueryable<T> source, string property)
{
return ApplyOrder<T>(source, property, "OrderBy");
}
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)
{
property = property.Trim();
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;
}
I call it using
model.ProfileList = Helper.OrderByHelper.OrderBy(model.ProfileList.Cast<ProfileData>().AsQueryable(), ResultSet.SortField).ToList<ProfileData>();
Now what i need to add is Collation, as i load list in-memory so using database collation has no sense here. So is there anyway to provide collation here in code. Is it possible? I google it but find nothing yet. Thanks in advance.
For example: here å is Norwegian character and should be added in last of the list, but it is treated as A in default collation
åtestå
cxvfg
Design
Upvotes: 1
Views: 623
Reputation: 26332
Here is my solution, may be it help someone in future. This is generic way to sort in-memory list using culture.
public class MyStringComparer : IComparer<string>
{
System.Globalization.CultureInfo culture = new System.Globalization.CultureInfo("no");
public int Compare(string x, string y)
{
return string.Compare(x, y, true, culture);
}
}
public static class OrderByHelper
{
public static IOrderedQueryable<T> OrderBy<T>(this IQueryable<T> source, string property)
{
return ApplyOrder<T>(source, property, "OrderBy");
}
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)
{
property = property.Trim();
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;
}
bool IsString = type.FullName == "System.String";
Type delegateType = typeof(Func<,>).MakeGenericType(typeof(T), type);
MyStringComparer comparer = new MyStringComparer();
LambdaExpression lambda = Expression.Lambda(delegateType, expr, arg);
object result = typeof(Queryable).GetMethods().Single(
method => method.Name == methodName
&& method.IsGenericMethodDefinition
&& method.GetGenericArguments().Length == 2
&& (IsString ? method.GetParameters().Length == 3 : method.GetParameters().Length == 2))
.MakeGenericMethod(typeof(T), type)
.Invoke(null, IsString ? new object[] { source, lambda, comparer } : new object[] { source, lambda });
return ((IOrderedQueryable<T>)result);
}
}
Upvotes: 0