When I observe developers writing solutions using LINQ to SQL or Entity Framework, I see a number of conversions occurring time and time again. Below are some of the more trivial utility method extensions I used when developing solutions based on LINQ to SQL and WPF—simple as they are I found them useful in a variety of situations.

Extension to remove data from a collection using a predicate.

public static void Remove<T>( this ICollection<T> data, Func<T, bool> predicate )
{
if( predicate == null )
{
data.Clear();
}
else
{
foreach( T item in data.Where( predicate ))
{
data.Remove( item );
}
}
}

 

Converting an enumerable to an ObservableCollection for data binding

public static ObservableCollection<T> ToObservableCollection<T>( this IEnumerable<T> collection ) 
{
List<T> list = new List<T>( collection.Count() );
using( IEnumerator<T> enumerator = collection.GetEnumerator() )
{
while( enumerator.MoveNext() )
{
list.Add( enumerator.Current );
}
}
return new ObservableCollection<T>( list );
}

The same but for a list

public static ObservableCollection<T> ToObservableCollection<T>( this List<T> collection ) 
{
return new ObservableCollection<T>( collection );
}