Question

下面代码在VS2012中调试出错；C# Web窗体界面

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
………………

string tetBoxName;
for (int n = 0; n < 40; n++)
{
tetBoxName = "TxtPassword"+n;
Control txtboxPWD = (Control)this.Page.FindControl(tetBoxName);
if (!DataValid.IsNullOrInt((txtboxPWD as TextBox).Text))
throw new CustomException("“密码”不是一个有效的整数，请您重新输入。");
intPWD[n] = (txtboxPWD as TextBox).Text.ToString();
}
txtpassword0的文本控件是存在的但还是会出错，，
请高手指教。。谢谢

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Answer 1

f (!DataValid.IsNullOrInt((txtboxPWD as TextBox).Text))换成

f (!DataValid.IsNullOrInt((TextBox)txtboxPWD.Text))

Answer 2

查看详细信息里看究竟哪个表达式为null