/// <summary>/// SQL关键字转换器/// </summary>public class SqlConverter : IKeywordsConvertible{public SqlConverter(string[] keywords){Keywords = keywords;}public SqlConverter() { }/// <summary>/// 关键字集合/// </summary>public string[] Keywords{get { return keywords; }set{this.keywords = new string[value.Length];for (int i = 0; i < value.Length; i++){this.keywords[i] = value[i].ToLower();}}}private string[] keywords;/// <summary>/// 字符缓冲区/// </summary>private StringBuilder charBuilder = new StringBuilder();/// <summary>/// 符号缓冲区/// </summary>private StringBuilder symboBuilder = new StringBuilder();/// <summary>/// 结果缓冲区/// </summary>private StringBuilder resBuilder = new StringBuilder();/// <summary>/// 上一个字符是否是字母/// </summary>private bool lastIsLetter;/// <summary>/// 临时变量/// </summary>private string temp;/// <summary>/// 转换/// </summary>/// <param name="source">要转换的字符串</param>/// <returns>转换结果</returns>public string Convert(string source){charBuilder.Clear();symboBuilder.Clear();resBuilder.Clear();lastIsLetter = true;temp = string.Empty;// 打散源字符串char[] charArray = source.ToArray<char>();// 遍历foreach (var c in charArray){if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')){// 如果上一个符号不是字母，就把符号缓冲区推送if (!lastIsLetter){PushSymbols();}charBuilder.Append(c);lastIsLetter = true;}else{// 如果上一个符号是字母，就把字母缓冲区推送if (lastIsLetter){PushLetters();}symboBuilder.Append(c);lastIsLetter = false;}}// 处理最后一个缓冲区if (lastIsLetter){PushLetters();}else{PushSymbols();}return resBuilder.ToString();}/// <summary>/// 将字符缓冲区推送至目标缓冲区/// </summary>private void PushLetters(){temp = charBuilder.ToString();if (Keywords.Contains(temp.ToLower())){resBuilder.Append(temp.ToUpper());}else{resBuilder.Append(temp);}charBuilder.Clear();}/// <summary>/// 将符号缓冲区推送至目标缓冲区/// </summary>private void PushSymbols(){resBuilder.Append(symboBuilder.ToString());symboBuilder.Clear();}}