VB语句转C#
Dim f As IO.Directory, fa(), fa1() As String
If
f.Exists(System.Windows.Forms.Application.StartupPath & "\学生资料\" &班级& "\" &姓名) = True
Then
fa = f.GetFiles(System.Windows.Forms.Application.StartupPath & "\学生资料\" &班级& "\" &姓名)

这个思路有点乱，麻烦给给意见 VB C# IO.Directory GetFiles
[解决办法]

 string []fa;
            string []fa1;

            if (System.IO.Directory.Exists(System.Windows.Forms.Application.StartupPath + @"\学生资料\" + 班级 + @"\" + 姓名))
                fa = System.IO.Directory.GetFiles(System.Windows.Forms.Application.StartupPath + @"\学生资料\" + 班级 + @"\" + 姓名);