using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;namespace Common
{public static class ExtensionFuncation{#region 判断是否为空/// <summary>/// 判断对象是否为null或者为空/// </summary>/// <param name="o"></param>/// <returns></returns>public static bool IfIsNullOrEmpty(this object o){if (null == o || o.Equals(""))return true;elsereturn false;}/// <summary>/// 判断对象是否为null或者为空/// </summary>/// <param name="o"></param>/// <returns></returns>public static bool IfIsNullOrEmpty(this string o){if (string.IsNullOrWhiteSpace(o)) return true;elsereturn false;}/// <summary>/// 判断对象是否为null或者为空/// </summary>/// <param name="o"></param>/// <returns></returns>public static bool IfIsNullOrEmpty<T>(this List<T> o){ if(null == o || o.Count == 0)return true;elsereturn false;}/// <summary>/// 判断对象是否为null或者为空/// </summary>/// <param name="o"></param>/// <returns></returns>public static bool IfIsNullOrEmpty<T>(this IList<T> o){ if(null == o || o.Count == 0)return true;elsereturn false;}/// <summary>/// 判断对象是否为null或者为空/// </summary>/// <param name="o"></param>/// <returns></returns>public static bool IfIsNullOrEmpty<K, V>(this Dictionary<K, V> o){if (null == o || o.Count == 0)return true;elsereturn false;}#endregion#region 带默认值的类型转换/// <summary>/// 类型转换带默认值/// </summary>/// <typeparam name="T"></typeparam>/// <param name="o"></param>/// <param name="defaultValue">如果转换失败返回的默认值</param>/// <returns></returns>public static T ConvertToType<T>(this object o, T defaultValue){try{return (T)System.Convert.ChangeType(o, typeof(T), null);}catch{return defaultValue;}}/// <summary>/// 类型转换带默认值/// </summary>/// <typeparam name="T"></typeparam>/// <param name="o"></param>/// <param name="defaultValue">如果转换失败返回的默认值</param>/// <returns></returns>public static T ConvertToType<T>(this string o, T defaultValue){try{return (T)System.Convert.ChangeType(o, typeof(T), null);}catch{return defaultValue;}}#endregion#region 提取中文首字母/// <summary>/// 返回中文首字母小写格式的/// </summary>/// <param name="paramChinese"></param>/// <param name="ifToUpper">是否转成大写字母返回</param>/// <returns></returns>public static string GetFirstLetter(this string paramChinese, bool ifToUpper){string strTemp = "";int iLen = paramChinese.Length;int i = 0;for (i = 0; i <= iLen - 1; i++){strTemp += GetCharSpellCode(paramChinese.Substring(i, 1));}return ifToUpper ? strTemp.ToUpper() : strTemp.ToLower();}/// <summary>  /// 得到一个汉字的拼音第一个字母，如果是一个英文字母则直接返回大写字母  /// </summary>  /// <param name="CnChar">单个汉字</param>  /// <returns>单个大写字母</returns>  private static string GetCharSpellCode(string paramChar){long iCnChar;byte[] ZW = System.Text.Encoding.Default.GetBytes(paramChar);//如果是字母，则直接返回  if (ZW.Length == 1){return paramChar.ToUpper();}else{// get the array of byte from the single char  int i1 = (short)(ZW[0]);int i2 = (short)(ZW[1]);iCnChar = i1 * 256 + i2;}//expresstion  //table of the constant list  // 'A'; //45217..45252  // 'B'; //45253..45760  // 'C'; //45761..46317  // 'D'; //46318..46825  // 'E'; //46826..47009  // 'F'; //47010..47296  // 'G'; //47297..47613  // 'H'; //47614..48118  // 'J'; //48119..49061  // 'K'; //49062..49323  // 'L'; //49324..49895  // 'M'; //49896..50370  // 'N'; //50371..50613  // 'O'; //50614..50621  // 'P'; //50622..50905  // 'Q'; //50906..51386  // 'R'; //51387..51445  // 'S'; //51446..52217  // 'T'; //52218..52697  //没有U,V  // 'W'; //52698..52979  // 'X'; //52980..53640  // 'Y'; //53689..54480  // 'Z'; //54481..55289  // iCnChar match the constant  if ((iCnChar >= 45217) && (iCnChar <= 45252)){return "A";}else if ((iCnChar >= 45253) && (iCnChar <= 45760)){return "B";}else if ((iCnChar >= 45761) && (iCnChar <= 46317)){return "C";}else if ((iCnChar >= 46318) && (iCnChar <= 46825)){return "D";}else if ((iCnChar >= 46826) && (iCnChar <= 47009)){return "E";}else if ((iCnChar >= 47010) && (iCnChar <= 47296)){return "F";}else if ((iCnChar >= 47297) && (iCnChar <= 47613)){return "G";}else if ((iCnChar >= 47614) && (iCnChar <= 48118)){return "H";}else if ((iCnChar >= 48119) && (iCnChar <= 49061)){return "J";}else if ((iCnChar >= 49062) && (iCnChar <= 49323)){return "K";}else if ((iCnChar >= 49324) && (iCnChar <= 49895)){return "L";}else if ((iCnChar >= 49896) && (iCnChar <= 50370)){return "M";}else if ((iCnChar >= 50371) && (iCnChar <= 50613)){return "N";}else if ((iCnChar >= 50614) && (iCnChar <= 50621)){return "O";}else if ((iCnChar >= 50622) && (iCnChar <= 50905)){return "P";}else if ((iCnChar >= 50906) && (iCnChar <= 51386)){return "Q";}else if ((iCnChar >= 51387) && (iCnChar <= 51445)){return "R";}else if ((iCnChar >= 51446) && (iCnChar <= 52217)){return "S";}else if ((iCnChar >= 52218) && (iCnChar <= 52697)){return "T";}else if ((iCnChar >= 52698) && (iCnChar <= 52979)){return "W";}else if ((iCnChar >= 52980) && (iCnChar <= 53688)){return "X";}else if ((iCnChar >= 53689) && (iCnChar <= 54480)){return "Y";}else if ((iCnChar >= 54481) && (iCnChar <= 55289)){return "Z";}else return ("?");}#endregion}
}