private static BinaryExpression GetExpression <T>(ParameterExpression param, GridHelper.Filter filter1, GridHelper.Filter filter2)
{
Expression result1 = GetExpression <T>(param, filter1);
Expression result2 = GetExpression <T>(param, filter2);
return(Expression.AndAlso(result1, result2));
}
private static Expression GetExpression <T>(ParameterExpression param, GridHelper.Filter filter)
{
// The member you want to evaluate (x => x.FirstName)
MemberExpression member = Expression.Property(param, filter.PropertyName);
// The value you want to evaluate
ConstantExpression constant = Expression.Constant(filter.Value);
// Determine how we want to apply the expression
switch (filter.Operator)
{
case GridHelper.Operator.Equals:
return(Expression.Equal(member, constant));
case GridHelper.Operator.Contains:
return(Expression.Call(member, containsMethod, constant));
case GridHelper.Operator.GreaterThan:
return(Expression.GreaterThan(member, constant));
case GridHelper.Operator.GreaterThanOrEqual:
return(Expression.GreaterThanOrEqual(member, constant));
case GridHelper.Operator.LessThan:
return(Expression.LessThan(member, constant));
case GridHelper.Operator.LessThanOrEqualTo:
return(Expression.LessThanOrEqual(member, constant));
case GridHelper.Operator.StartsWith:
return(Expression.Call(member, startsWithMethod, constant));
case GridHelper.Operator.EndsWith:
return(Expression.Call(member, endsWithMethod, constant));
}
return(null);
}