刪除數組重複值

好比，在數據庫中查詢到某個字段的值 aa,bb,aa,dd,cc,bb,aa,ee，如今要把重複的值去掉，那麼咱們能夠把該值查詢出來，而後賦值到數組，刪除重複值。

好比咱們把查詢到的值放到datatable裏，這裏演示第一行第二列的操做。多行的話，for循環便可。

   string mydata = ds.Tables["data"].Rows[i][1].ToString();
                string ls_str = mydata;
                string[] str_num = ls_str.Split(',');
                ArrayList al = new ArrayList();
                for (int j = 0; j< str_num.Length;j++)
                {

                    //判斷是否已經存在                     if (al.Contains(str_num[j]) == false)                     {                         al.Add(str_num[j]);                     }                 }                 str_num = new String[al.Count];                 str_num = (string[])al.ToArray(typeof(string));                 for (int k = 0; k < str_num.Length; k++) {                     Response.Write(str_num[k]);                     Response.Write("，");                 }