SQL Server中SMO备份数据库进度条不显示？

xiang8

　　有朋友提到一个奇怪的问题，用SMO备份数据库时不显示进度条，也就是进度条事件PercentComplete不触发。
　　今天试了一下，果然有点奇怪。
　　代码如下：
using Microsoft.SqlServer.Management.Smo;using Microsoft.SqlServer.Management.Common;private void btnBackup_Click(object sender, EventArgs e){btnBackup.Enabled = false;Thread tr = new Thread(new ThreadStart(doBackup));tr.Priority = ThreadPriority.AboveNormal;tr.Start();//Thread.Sleep(3000);}/// <summary>/// 备份数据库/// </summary>public void doBackup(){pbDemo.Value = 0;pbDemo.Maximum = 100;pbDemo.Style = ProgressBarStyle.Blocks;//pbDemo.Step = 10;Server srv = new Server(@"(local)");Backup backup = new Backup();backup.Action = BackupActionType.Database;backup.Database = "btnet";backup.Incremental = false;backup.Devices.Add(new BackupDeviceItem(@"C:\agronet09.bak", DeviceType.File));backup.Initialize = true;backup.PercentCompleteNotification = 10;backup.PercentComplete += new PercentCompleteEventHandler(backup_PercentComplete);//backup.Checksum = true;backup.SqlBackup(srv);}public void backup_PercentComplete(object sender, Microsoft.SqlServer.Management.Smo.PercentCompleteEventArgs e){this.Invoke(new displayProgress_delegate(displayProgress), e.Percent);//Application.DoEvents();}public delegate void displayProgress_delegate(int progress);public void displayProgress(int progress){this.lbProgress.Text = "已完成[" + progress.ToString() + " %]";pbDemo.Value = progress;btnBackup.Enabled = (progress == 100);}
症状如下：结果正确执行，但进度条不显示。
　　刚开始以为是线程问题，后来发现不是这个原因。
　　又试了另外一段代码
　　using Microsoft.SqlServer.Management.Smo;using Microsoft.SqlServer.Management.Common;using System.Diagnostics;static void Main(string[] args){BackupDatabase("ap4\\agronet09", "agronet2008", "c:\\Northind_3.bak");Console.WriteLine(Environment.NewLine + "Press any key to continue.");Console.ReadKey();}public static  void BackupDatabase(string serverName, string databaseName, string fileName){Console.WriteLine("*** Backing up ***");Server server = new Server(serverName);Backup backup = new Backup();backup.Action = BackupActionType.Database;backup.Database = databaseName;backup.Incremental = false;backup.Initialize = true;backup.LogTruncation = BackupTruncateLogType.Truncate;BackupDeviceItem backupItemDevice = new BackupDeviceItem(fileName, DeviceType.File);backup.Devices.Add(backupItemDevice);backup.PercentCompleteNotification = 10;backup.PercentComplete += backup_PercentComplete;backup.Complete +=backup_Complete;backup.SqlBackup(server);}protected static  void backup_PercentComplete(object sender, PercentCompleteEventArgs e){Console.WriteLine(e.Percent + "% processed.");//Application.();System.Threading.Thread.Sleep(1000);}protected static  void backup_Complete(object sender, ServerMessageEventArgs e){Console.WriteLine(Environment.NewLine + e.ToString());}
结果还是不显示。
　　后来突然想到会不会是文件太小，试了一个200M的数据文件，果然成功显示：


　　后来经反复实验，发现SQL server 2000约在数据文件加日志文件大于6M左右时显示进度条。
　　而Sqlserver 2008 r2大约在3M时显示进度条。可能跟机器也有关系。
　　注意：SQL server 2008 r2版规定主数据文件必须大于3M，微软真牛！

　　参考文章：
　　http://msdn.microsoft.com/zh-cn/magazine/cc163409.aspx


邀月注：本文版权由邀月和CSDN共同所有，转载请注明出处。
助人等于自助! 3w@live.cn