只允許輸入數字型Textbox演示

有一個需求，需要在GridView中批量輸入數字！

於是想到封裝一個TextBox

代碼如下：

public class NumberText : TextBox
    {
        private const string SMB_NUMBER_SCRIPT_ID = "{c4f7dcfd-8f9b-4fe8-8bd1-4a8a1f145c0c}";
        private const string SMB_NUMBER_SCRIPT_ONLY_HOOK = "return NumberEditor_KeyPress_Handle(this)";
        private const string SMB_NUMBER_SCRIPT_ONLY_SCRIPT = "<script language=\"javascript\">\n" +
            "function NumberEditor_KeyPress_Handle(ctrl)\n{{" +
            "if(event.keyCode == 13) \n return true;\n" +
            "if(event.keyCode<48 || event.keyCode>57 )\n" +
            "return false;\n else \n return true;\n}}" +
            "</script>";
        private void RenderJavscript()
        {
            if (!Page.ClientScript.IsClientScriptBlockRegistered(SMB_NUMBER_SCRIPT_ID))
            {
                Page.ClientScript.RegisterClientScriptBlock(Page.GetType(), SMB_NUMBER_SCRIPT_ID, string.Format(SMB_NUMBER_SCRIPT_ONLY_SCRIPT, base.ID));
            }
        }
        protected override void AddAttributesToRender(HtmlTextWriter writer)
        {
            base.AddAttributesToRender(writer);
            writer.AddAttribute("OnKeyPress", SMB_NUMBER_SCRIPT_ONLY_HOOK);
        }
        protected override void OnPreRender(EventArgs e)
        {
            base.OnPreRender(e);
            RenderJavscript();
        }
        public NumberText()
            : base()
        { }
    }