Lambda expression NotContains operator Exists?

Question

Lambda expression for Contains operator I am able to generate using this code.

Expression

Company => Company.Name.Contains("test1")

Source code

var method = typeof(string).GetMethod("Contains", new[] { typeof(string) }); 
var startsWithDishExpr = Expression.Call(argLeft, method, argRight);

Its working fine for Contains operator. How to modify to code to work for NotContains operator.

Source code

var method = typeof(string).GetMethod("NotContains", new[] { typeof(string) }); 
var startsWithDishExpr = Expression.Call(argLeft, method, argRight);

NotContains operator not working. Anybody have suggestion?

Answer 1

There is no string.NotContains method, so creating a call to a method called NotContains doesn't work.

A simple solution is to combine the not operator, with the Contains method. Just like normally you'd write !x.Contains(y) and not x.NotContains(y).

To create such an expression you can use Expression.Not(callExpression).