小编Pen*_*uen的帖子

有没有性能指标？或者我真的得到这样的结果:

锯齿状阵列:2000 ms
阵列:300​​0 ms
ArrayList:4000 ms

如何编写方法来获得性能结果？

这个delow查询给我一些错误:

declare @date1 nvarchar(100) , @date2 nvarchar(100)

select @date1='2009-04-20', @date2='2009-05-20'

select top 10 t.VisitingCount , t.Page
    from (
           select  Count(Page) as VisitingCount,Page
               from scr_SecuristLog   
               where Date between @date1 and @date2  
                   and [user] in (select USERNAME             
                                      from scr_CustomerAuthorities
                                 )  
               group by Page order by [VisitingCount] desc 
         ) t 

错误:

除非还指定了TOP或FOR XML,否则ORDER BY子句在视图,内联函数,派生表,子查询和公用表表达式中无效.

如果我尝试将以下数据添加到任何文本文件错误occyred:"NullReferenceException未处理." Tex.Writeline(li)出错....

细节:对象引用未设置为对象的实例.

  public void WriteScript(List myTextList)
        {
            FileInfo f = new FileInfo(@"C:\temp\Scripts.txt");
            StreamWriter Tex = null;
            if(!f.Exists)
                f.CreateText();
            else
                f.AppendText();
            foreach (string li in myTextList)
            {
                Tex.WriteLine(li);
                Tex.Write(Tex.NewLine);
                Tex.WriteLine("GO");
                Tex.Write(Tex.NewLine);
            }
                Tex.Close();
                Tex.Dispose();

        }

Create table ENG_PREP (ENG_PREP_ID integer PRIMARY KEY identity(1,1), [ENG_PREP_MPD_REFERENCE]  nvarchar(3000) , [ENG_PREP_TASK_DESCRIPTION]  nvarchar(3000) , [ENG_PREP_ZONE]  nvarchar(3000) , [ENG_PREP_SUBZONE]  nvarchar(3000) , [ENG_PREP_PREPERATION_NO#]  nvarchar(3000) , [ENG_PREP_PREPERATION_DESCRIPTION]  nvarchar(3000) , [ENG_PREP_RELATED_PREPERATION]  nvarchar(3000) , [ENG_PREP_OPEN_MH]  nvarchar(3000) , [ENG_PREP_CLOSE_MH]  nvarchar(3000) , [ENG_PREP_ESTIMATED_MH]  nvarchar(3000) , [ENG_PREP_CREW_DONE]  nvarchar(3000) , [ENG_PREP_SKILL_DONE]  nvarchar(3000) , [ENG_PREP_MAINTENANCE_DATA] …

如果我尝试排序我的列返回0值.但我需要最大值去除值,但如何？

 for (int j = 0; j < dTable.Columns.Count; j++)
                for (int i = 0; i < dTable.Rows.Count; i++)
                {
                    mycounter[i] = dTable.Rows[i][j].ToString().Length;
                }
            mycounter = mycounter.OrderBy(i => i).ToArray();

            mycounter.Reverse();
            MessageBox.Show(mycounter[0].ToString());

 class Program
    {
        static void Main(string[] args)
        {
            mylist myitems1 = new mylist("Yusuf","Karatoprak");
            SelectedItemsList slist = new SelectedItemsList();
            slist.Items.Add(myitems1);
            foreach( object o in slist.Items)
            Console.Write(o.ToString()+"\n");
            Console.ReadKey();
        }
    }

    public class mylist
    {
        private string Ad;
        private string SoyAd;
        public mylist(string ad, string soyad)
        {
            Ad = ad;
            SoyAd = soyad;
        }

        public override string ToString()
        {
            return "Ad:" + this.Ad;
        }
    }
    public class SelectedItemsList
    {
        public List Items;


    public SelectedItemsList()
    {
        Items = new List<mylist>();

    }
}</code></pre>

我想返回一个arylylist或列表形式的mylist类,但如何？返回this.Ad,也重新调整.SayayAd蚀刻.请看ToString()程序:它是返回广告,但我想一起返回Ad也是SoyAd.列表中不仅有广告,还有广告,SoyAd.

可能重复:
是否可以解密md5哈希？

我散列数据,ComputeHash如何从散列数据中学习原始数据？

private void btn_Hash_Click(object sender, EventArgs e)
{
    HashAlgorithm ha = HashAlgorithm.Create();
    Stream file = new FileStream(@"C:\temp\simetrik.txt", FileMode.Open, FileAccess.Read);
    hashClass.hash = ha.ComputeHash(file);

    listBox1.Items.Add(BitConverter.ToString(hashClass.hash));
}

我两天前设置了Windows 7.但是我下载了.net framework 3.5.我认为Windows 7包括.net 3.5