//委托
 Func<string, double> toDouble = s =>
            {
                double d = 0d;

                if (!string.IsNullOrEmpty(s))
                    double.TryParse(s, out d);

                return d;
            };
            if (toDouble(txtfirstjdjes.Text) +
                toDouble(txtsecondlyjdjes.Text) +
                toDouble(txtthirdjdjes.Text) +
                toDouble(txtfourjdjes.Text) > toDouble(lblysjes))

 1  public static class Objects
 2     {
 3         /// <summary>
 4         /// 将对象安全的转换为int类型（如果转换失败，则为默认值 true:1 false:0）
 5         /// </summary>
 6         /// <param name="o"></param>
 7         /// <param name="defaultValue">默认值</param>
 8         /// <returns></returns>
 9         public static int ToSafeInt32(this object o, int defaultValue)
10         {
               int num = defaultValue;
16             if (o.GetType() == Type.GetType("System.Boolean"))
17             {
18                 return (Convert.ToBoolean(o) ? 1 : 0);
19             }
20             try
21             {
22                 num = Convert.ToInt32(o);
23             }
24             catch
25             {
26             }
27             return num;
28         }
　　}