方法一：使用正则表达式

1//脏字典数据存放文件路径
2        private static string FILE_NAME="zang.txt";
3        //脏数据字典表，如：脏数据一|脏数据二|脏数据三
4        public static string dirtyStr="";
5        
6        public ValidDirty()
7        {
8            if (HttpRuntime.Cache["Regex"]==null)
9            {
10                dirtyStr=ReadDic();
11                //用于检测脏字典的正则表达式
12                Regex validateReg= new Regex("^((?!" dirtyStr ").(?<!" dirtyStr "))*$",RegexOptions.Compiled|RegexOptions.ExplicitCapture);    
13                HttpRuntime.Cache.Insert("Regex" ,validateReg,null,DateTime.Now.AddMinutes(20) ,TimeSpan.Zero);
14            }
15            
16        }
17        private string ReadDic()
18        {
19            FILE_NAME=Environment.CurrentDirectory "\\" FILE_NAME;
20
21            if (!File.Exists(FILE_NAME))
22            {
23                Console.WriteLine("{0} does not exist.", FILE_NAME);
24                return "";
25            }
26            StreamReader sr = File.OpenText(FILE_NAME);
27            String input="";
28            while (sr.Peek() > -1)
29            {
30                input  = sr.ReadLine() ;
31            }
32            
33            sr.Close();
34            return input;
35
36        }
37
38        
39        public bool ValidByReg(string str)
40        {
41            Regex reg=(Regex)HttpRuntime.Cache["Regex"];
42            return reg.IsMatch(str) ;
43            
44        }

感觉这种方法的执行效率不是很高，简单的测试了一下 1000字的文章，脏字典有800多个关键字
式了一下是 1.238秒，大家有没有更好的方法，请不吝赐教！

方法二：普通循环查找方法

    public bool ValidGeneral(string str)
        {
            
            if(!File.Exists(FILE_NAME))
            {
                Console.WriteLine("文件路径或者文件路径不存在错误信息") ;
                return false;
            }
            else
            {
                StreamReader objReader = new StreamReader(FILE_NAME,System.Text.Encoding.GetEncoding("gb2312"));
                string sLine="";
                ArrayList arrText = new ArrayList();

                while (sLine != null)
                {
                    sLine = objReader.ReadLine();
                    if (sLine != null)
                        arrText.Add(sLine);
                    
                }
                objReader.Close();

                foreach (string sOutput in arrText)
                {
                    string[] strArr=sOutput.Split('|');
                    
                    for (int i = 0; i < strArr.Length; i  )
                    {
                        if (str.IndexOf(strArr[i])!=-1)
                        {
                            return false;    
                        }
                        
                    }
                    
                }
                return true;

            }

        }

以下是测试的方法，有什么问题还大家请指出！

1DateTime t1 =DateTime.Now;
2            string str="213";
3            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
4            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
5            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
6            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
7            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
8            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
9            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
10            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
11            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
12            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";    
13            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
14            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
15            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
16            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
17            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
18            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
19            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
20            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
21            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
22            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
23            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
24            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
25            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
26            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
27            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
28            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
29            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
30            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
31            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
32            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
33            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
34            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
35            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
36            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
37            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
38            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
39            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
40            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
41            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
42            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
43            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
44            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
45            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
46            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
47            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
48            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
49            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
50            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
51            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
52            str ="珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋珍惜水晶之恋";
53            ValidDirty vd=new ValidDirty() ;
54            Console.WriteLine(vd.ValidByReg(str))  ;
55            DateTime t2 =DateTime.Now;
56            TimeSpan ts=t2-t1;
57            Console.WriteLine(ts.TotalMilliseconds) ;
58            Console.Read() ;