string[] ss = new string[5] { "a", "b", "c", "a", "d" };
            var v = from s in ss group s by s;
            if (v.Count() == ss.Length)
            {
                MessageBox.Show("一样");
            }

------解决方案--------------------

冒泡 比较
int length=sp.length-1;
bool bl=false;
for (int i=0,i<length;i++){
  bl=false;
  for(int j=length;j>i;j--){
      if(sp[j]!=sp[j-1]){
        bl=true;
      }
     if(bl){//存在不同直接停止循环
     break;
     }
  }
if(bl){
//不相同
}
}