C# 字符串按设置的格试在前面或后面增加空格或其它字符

 1  public string lengadd(string stringa, string stringb, int count, int mode)  //以stringa的长度,未到count的长度则增加stringb,mode属性0是增加前面,1是增加后面
 2         {
 3             int stringaa = System.Text.Encoding.Default.GetBytes(stringa).Length;
 4             if (mode == 0)
 5             {
 6                 for (int i = 1; i <= (count - stringaa); i++)
 7                 {
 8                     stringa = stringb + stringa;
 9                 }
10 
11             }
12             else
13             {
14                 for (int i = 1; i <= (count - stringaa); i++)
15                 {
16                     stringa = stringa + stringb;
17                 }
18 
19             }
20             return stringa;
21         }