（1）PairString

 1    public struct PairString
 2    {
 3        public string OldValue;
 4        public string NewValue;
 5        public bool IsRightFilter;
 6        public bool IsLeftFilter;
 7
 8        public PairString(string oldValue, string newValue)
 9        {
10            OldValue=oldValue;
11            NewValue=newValue;
12            IsRightFilter=true;
13            IsLeftFilter=true;
14        }
15
16        public PairString(string oldValue, string newValue, bool isRightFilter, bool isLeftFilter)
17        {
18            OldValue=oldValue;
19            NewValue=newValue;
20            IsRightFilter=isRightFilter;
21            IsLeftFilter=isLeftFilter;
22        }
23    }

（2）采用Replace实现

 1    public class StringFilter
 2    {
 3        private PairString[] _filterSet=null;
 4
 5        public PairString[] FilterSet
 6        {
 7            get
 8            {
 9                return _filterSet;
10            }
11            set
12            {
13                _filterSet=value;
14            }
15        }
16
17
18        public StringFilter()
19        {
20        }
21
22
23        public virtual  string Filter(string input)
24        {
25            foreach (PairString p in FilterSet)
26            {
27                if(p.IsRightFilter==true) input=input.Replace(p.OldValue,p.NewValue);
28            }
29            return input;
30        }
31
32        public virtual string AntiFilter(string input)
33        {
34            foreach (PairString p in FilterSet)
35            {
36                if(p.IsLeftFilter==true) input=input.Replace(p.NewValue,p.OldValue);
37            }
38            return input;
39        }
40    }