帮忙解决一下吧
float c,r;
string s2, s3;
r = timer1.Interval;
c = r/ 1000;
d = d + c;
s2 = d.ToString();
t =s2.IndexOf(".");
s3= s2.SubString(0, t+1);
运行时间.Text = s3;
RunBoard();
错误1“string”不包含“SubString”的定义,并且找不到可接受类型为“string”的第一个参数的扩展方法“SubString”(是否缺少 using 指令或程序集引用?)E:\C#\shexiangjiqiren\shexiangjiqiren\Form7.cs22820shexiangjiqiren
[解决办法]
SubString应该为Substring,第二个s字母应该是小写,c#是大小写敏感的,