通用型別轉換

    /// <summary>
    /// Converts a data type to another data type.
    /// </summary>
    public static class Cast
    {
        /// <summary>
        /// Converts input to Type of default value or given as typeparam T
        /// </summary>
        /// <typeparam name="T">typeparam is the type in which value will be returned, it could be any type eg. int, string, bool, decimal etc.</typeparam>
        /// <param name="input">Input that need to be converted to specified type</param>
        /// <param name="defaultValue">defaultValue will be returned in case of value is null or any exception occures</param>
        /// <returns>Input is converted in Type of default value or given as typeparam T and returned</returns>
        public static T To<T>(object input, T defaultValue)
        {
            var result = defaultValue;
            try
            {
                if (input == null || input == DBNull.Value) return result;
                if (typeof (T).IsEnum)
                {
                    result = (T) Enum.ToObject(typeof (T), To(input, Convert.ToInt32(defaultValue)));
                }
                else
                {
                    result = (T) Convert.ChangeType(input, typeof (T));
                }
            }
            catch (Exception ex)
            {
                Tracer.Current.LogException(ex);
            }

            return result;
        }
        
        /// <summary>
        /// Converts input to Type of typeparam T
        /// </summary>
        /// <typeparam name="T">typeparam is the type in which value will be returned, it could be any type eg. int, string, bool, decimal etc.</typeparam>
        /// <param name="input">Input that need to be converted to specified type</param>
        /// <returns>Input is converted in Type of default value or given as typeparam T and returned</returns>
        public static T To<T>(object input)
        {
            return To(input, default(T));
        }

        

    }

用途：

std.Name = Cast.To<string>(drConnection["Name"]);
std.Age = Cast.To<int>(drConnection["Age"]);
std.IsPassed = Cast.To<bool>(drConnection["IsPassed"]);

// Casting type using default value
//Following both ways are correct
// Way 1 (In following style input is converted into type of default value)
std.Name = Cast.To(drConnection["Name"], "");
std.Marks = Cast.To(drConnection["Marks"], 0);
// Way 2    
std.Name = Cast.To<string>(drConnection["Name"], "");
std.Marks = Cast.To<int>(drConnection["Marks"], 0);