.net擴充套件方法——型別轉換

1. ObjToBool：object型轉換為bool型
2. StrToBool：string型轉換為bool型
3. ObjToInt：將物件轉換為Int32型別
4. StrToInt：將字串轉換為Int32型別
5. StrToIntNull
6. ObjToDecimal
7. StrToDecimal
8. StrToDecimalNull
9. ObjToDouble
10. StrToDouble
11. StrToGuid
12. StrToDateTime
13. ObjToDateTime
14. ObjToStr

        #region 型別轉換

        /// <summary>
 

        /// object型轉換為bool型
        /// </summary>
        /// <param name="strValue">要轉換的字串</param>
        /// <param name="defValue">預設值</param>
        /// <returns>轉換後的bool型別結果</returns>
        public static bool ObjToBool(this object expression, bool defValue)
        {
            
 
if (expression != null)
                return ObjToBool(expression, defValue);

            return defValue;
        }

        /// <summary>
        /// string型轉換為bool型
        /// </summary>
        /// <param name="strValue">要轉換的字串</param>
        /// <param name="defValue">預設值</param>
 

        /// <returns>轉換後的bool型別結果</returns>
        public static bool StrToBool(this string expression, bool defValue)
        {
            if (expression != null)
            {
                if (string.Compare(expression, "true", true) == 0 || expression == "是")
                    return true;
                else if (string.Compare(expression, "false", true) == 0 || expression == "否")
                    return false;
            }
            return defValue;
        }

        /// <summary>
        /// 將物件轉換為Int32型別
        /// </summary>
        /// <param name="expression">要轉換的字串</param>
        /// <param name="defValue">預設值</param>
        /// <returns>轉換後的int型別結果</returns>
        public static int ObjToInt(this object expression, int defValue)
        {
            if (expression != null)
                return StrToInt(expression.ToString(), defValue);

            return defValue;
        }

        /// <summary>
        /// 將字串轉換為Int32型別
        /// </summary>
        /// <param name="expression">要轉換的字串</param>
        /// <param name="defValue">預設值</param>
        /// <returns>轉換後的int型別結果</returns>
        public static int StrToInt(this string expression, int defValue)
        {
            if (expression == null)
                return defValue;

            int val;
            if (Int32.TryParse(expression.Replace(",", ""), out val))
            {
                return val;
            }
            return defValue;
        }
        public static int? StrToIntNull(this string expression)
        {
            if (expression == null)
                return null;

            int val;
            if (Int32.TryParse(expression.Replace(",", ""), out val))
            {
                return val;
            }
            return null;
        }


        /// <summary>
        /// 將字串轉換為Int32型別
        /// </summary>
        /// <param name="expression">要轉換的字串</param>
        /// <param name="defValue">預設值</param>
        /// <returns>轉換後的int型別結果</returns>
        public static int? StrToInt(this string expression)
        {
            if (expression == null)
                return null;

            int val;
            if (Int32.TryParse(expression.Replace(",", ""), out val))
            {
                return val;
            }
            return null;
        }

        /// <summary>
        /// Object型轉換為decimal型
        /// </summary>
        /// <param name="strValue">要轉換的字串</param>
        /// <param name="defValue">預設值</param>
        /// <returns>轉換後的decimal型別結果</returns>
        public static decimal ObjToDecimal(this object expression, decimal defValue)
        {
            if (expression != null)
                return StrToDecimal(expression.ToString(), defValue);

            return defValue;
        }

        /// <summary>
        /// string型轉換為decimal型
        /// </summary>
        /// <param name="strValue">要轉換的字串</param>
        /// <param name="defValue">預設值</param>
        /// <returns>轉換後的decimal型別結果</returns>
        public static decimal StrToDecimal(this string expression, decimal defValue)
        {
            if (expression == null)
                return defValue;

            decimal val;
            if (decimal.TryParse(expression.Replace(",", ""), out val))
            {
                return val;
            }
            return defValue;
        }

        public static decimal? StrToDecimalNull(this string expression)
        {
            if (expression == null)
                return null;

            decimal val;
            if (decimal.TryParse(expression.Replace(",", ""), out val))
            {
                return val;
            }
            return null;
        }
        /// <summary>
        /// Object型轉換為double型
        /// </summary>
        /// <param name="strValue">要轉換的字串</param>
        /// <param name="defValue">預設值</param>
        /// <returns>轉換後的int型別結果</returns>
        public static double ObjToDouble(this object expression, double defValue)
        {
            if (expression != null)
                return StrToDouble(expression.ToString(), defValue);

            return defValue;
        }

        /// <summary>
        /// 將字串轉換為Double型別
        /// </summary>
        /// <param name="expression">要轉換的字串</param>
        /// <param name="defValue">預設值</param>
        /// <returns>轉換後的int型別結果</returns>
        public static double StrToDouble(this string expression, int defValue)
        {
            if (expression == null)
                return defValue;

            double val;
            if (Double.TryParse(expression.Replace(",", ""), out val))
            {
                return val;
            }
            return defValue;
        }

        /// <summary>
        /// string型轉換為double型
        /// </summary>
        /// <param name="strValue">要轉換的字串</param>
        /// <param name="defValue">預設值</param>
        /// <returns>轉換後的int型別結果</returns>
        public static double StrToDouble(this string expression, double defValue)
        {
            if (expression == null)
                return defValue;

            double val;
            if (double.TryParse(expression.Replace(",", ""), out val))
            {
                return val;
            }
            return defValue;
        }

        /// <summary>
        /// string型轉換為Guid型
        /// </summary>
        /// <param name="strValue">要轉換的字串</param>
        /// <returns>轉換後的int型別結果</returns>
        public static Guid? StrToGuid(this string expression)
        {
            if (expression == null)
                return null;

            Guid val;
            if (Guid.TryParse(expression, out val))
            {
                return val;
            }
            return null;
        }

        /// <summary>
        /// 將物件轉換為日期時間型別
        /// </summary>
        /// <param name="str">要轉換的字串</param>
        /// <param name="defValue">預設值</param>
        /// <returns>轉換後的int型別結果</returns>
        public static DateTime? StrToDateTime(this string str, DateTime? defValue)
        {
            if (!string.IsNullOrEmpty(str))
            {
                DateTime dateTime;
                if (DateTime.TryParse(str, out dateTime))
                    return dateTime;
            }
            return defValue;
        }

        /// <summary>
        /// 將物件轉換為日期時間型別
        /// </summary>
        /// <param name="str">要轉換的字串</param>
        /// <returns>轉換後的int型別結果</returns>
        public static DateTime? StrToDateTime(this string str)
        {
            return StrToDateTime(str, null);
        }

        /// <summary>
        /// 將物件轉換為日期時間型別
        /// </summary>
        /// <param name="obj">要轉換的物件</param>
        /// <returns>轉換後的int型別結果</returns>
        public static DateTime? ObjToDateTime(this object obj)
        {
            return StrToDateTime(obj.ToString());
        }

        /// <summary>
        /// 將物件轉換為日期時間型別
        /// </summary>
        /// <param name="obj">要轉換的物件</param>
        /// <param name="defValue">預設值</param>
        /// <returns>轉換後的int型別結果</returns>
        public static DateTime? ObjToDateTime(this object obj, DateTime defValue)
        {
            return StrToDateTime(obj.ToString(), defValue);
        }

        /// <summary>
        /// 將物件轉換為字串
        /// </summary>
        /// <param name="obj">要轉換的物件</param>
        /// <returns>轉換後的string型別結果</returns>
        public static string ObjToStr(this object obj)
        {
            if (obj == null)
                return "";
            return obj.ToString().Trim();
        }

        #endregion 物件轉換處理