/// <summary>
/// 返回一个new表达式(Return a new expression)
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="PropertyName"></param>
/// <returns></returns>
public static Expression <Func <T, Object> > GetExpression <T>(params string[] PropertyName) where T : class, new()
{
List <MemberBinding> Exps = new List <MemberBinding>();
ParameterExpression Parameter = Expression.Parameter(typeof(T), "t");
PropertyName.ToEach <String>(Item =>
{
MemberExpression PropertyExpress = Expression.Property(Parameter, Item);
UnaryExpression ConvterExpress = Expression.Convert(PropertyExpress, typeof(T).GetProperty(Item).PropertyType);
Exps.Add(Expression.Bind(typeof(T).GetProperty(Item), PropertyExpress));
});
MemberInitExpression Member = Expression.MemberInit(Expression.New(typeof(T)), Exps);
return(Expression.Lambda <Func <T, Object> >(Member, Parameter));
}