在Textbox的輸入中﹐我們常常需要控制輸入的類型﹐比如說只能輸入數字﹐當然實現的方法很多﹐我總結了一下我做過的一些項目﹐我常會使用以下這三種﹕
1﹑使用Try...Catch
        private static bool IsNumeric(string itemValue,int intFLag)
        {
            try
            {
                int i = Convert.ToInt32(itemValue);
                return true;
             }
            catch
            {
                return false;
             }
         }

2﹑使用正則表達式
using System.Text.RegularExpressions;
        
         private static bool IsNumeric(string itemValue)
        {
            return (IsRegEx("^(-?[0-9]×[.]×[0-9]{0,3})$", itemValue));
         }

        private static bool IsRegEx(string regExValue, string itemValue)
        {
            try
            {
                 Regex regex = new System.Text.RegularExpressions.Regex(regExValue);
                if (regex.IsMatch(itemValue)) return true;
                else                          return false;
             }
            catch (Exception )
            {
                return false;
             }
            finally
            {
             }
         }

3﹑判斷輸入的keyCode