Convert a property getter to a setter
In the process of adding some strongly-typed extensions to the official MongoDB C# driver I needed some code to convert a property getter into a property setter. The following static method does that, turning e => e.Field into an Action method you can call to set the value of 'Field'.
/// <summary>
/// Convert a lambda expression for a getter into a setter
/// </summary>
public static Action<T, U> GetSetter<T,U>(Expression<Func<T, U>> expression)
{
var memberExpression = (MemberExpression)expression.Body;
var property = (PropertyInfo)memberExpression.Member;
var setMethod = property.GetSetMethod();
var parameterT = Expression.Parameter(typeof(T), "x");
var parameterU = Expression.Parameter(typeof(U), "y");
var newExpression = Expression.Lambda<Action<T, U>>(
Expression.Call(parameterT, setMethod, parameterU), parameterT, parameterU);
return newExpression.Compile();
}
