c# - can linq expression be case insensitive

Question

i am leveraging this project to use jqgrid to filter and sort collections. The one missing feature is that this example is not doing case insensitive search which i need.

So if a user types in "Test" i want it to match with "TEST", "TeST", etc . .

i have code that looks like this:

            case WhereOperation.Equal:
                condition = Expression.Equal(memberAccessToString, filter);
                lambda = Expression.Lambda(condition, parameter);
                break;
            case WhereOperation.NotEqual:
                condition = Expression.NotEqual(memberAccessToString, filter);
                lambda = Expression.Lambda(condition, parameter);
                break;
            case WhereOperation.Contains:
                condition = Expression.Call(memberAccessToString,
                    typeof(string).GetMethod("Contains"),
                    Expression.Constant(value));
                lambda = Expression.Lambda(condition, parameter);
                break;

is there anyway to have these checks below being case insensitive so "Test" would equal "TEST"

Expression.NotEqual    
Expression.Equal
Expression.Call(memberAccessToString,
                    typeof(string).GetMethod("Contains"),

Answer 1

You could convert both values to lowercase before doing the comparison. Here's an example for Contains:

case WhereOperation.Contains:
    var toLower = Expression.Call(memberAccessToString,
                                  typeof(string).GetMethod("ToLower", System.Type.EmptyTypes));
    condition = Expression.Call(toLower,
                                typeof(string).GetMethod("Contains"),
                                Expression.Constant(value.ToString().ToLower()));
    lambda = Expression.Lambda(condition, parameter);
    break;

Note, however, that this won't pass the Turkey test.