定时器的使用

下面是一段定时器使用的代码:

//开始读取事件
        private void btRead_Click(object sender, System.EventArgs e)
        ...{
            btRead.Enabled = false;
            btStopRead.Enabled = true;
            fileClass.CreateDirectory("RecordXmlFolder");
            DataSet ds = new DataSet();
            DataSet ds1 = new DataSet();
            ds = xmlClass.GetFullXml("SettingXmlFolder/SetFolderAndTime.xml","Root");
            int count = ds.Tables[0].Rows.Count;
            ds1 = ds.Copy();
            ds1.Clear();

            for(int i=0;i<count;i++)
            ...{
                string folder = ds.Tables[0].Rows[i]["Folder"].ToString();
                if(folder.EndsWith(@""))
                ...{
                    folder = folder.Substring(0,folder.Length-1);
                }
                string userName = ds.Tables[0].Rows[i]["UserName"].ToString();
                string password = ds.Tables[0].Rows[i]["Password"].ToString();
                //连接网络
                ConnectRemoteMachine(folder,userName,password);

                if(Directory.Exists(folder))
                ...{
                    ds1.Tables[0].NewRow();
                    ds1.Tables[0].Rows.Add(ds.Tables[0].Rows[i].ItemArray);
                }
                else
                ...{
                    MessageBox.Show("共享目录"+folder+"不存在!");
                }
            }
            timer = new System.Threading.Timer[ds1.Tables[0].Rows.Count];
            for(int i=0;i<ds1.Tables[0].Rows.Count;i++)
            ...{
                string [] state = new string[] ...{
                                                   ds1.Tables[0].Rows[i]["Folder"].ToString(),
                                                   ds1.Tables[0].Rows[i]["Type"].ToString()
                };

                timer[i] = new System.Threading.Timer(new System.Threading.TimerCallback(BeginRead),state,0,Convert.ToInt32(ds.Tables[0].Rows[i]["Time"].ToString()));

            }
        }

        //定时读取文件
        private void BeginRead(object state)
        ...{    
            lock(this)
            ...{
                string[] arr = (string[])state;

                //读取网络文件
                GetContents(arr[0],Convert.ToInt32(arr[1]));
            }
        }

其中:

timer[i] = new System.Threading.Timer(new System.Threading.TimerCallback(BeginRead),state,0,Convert.ToInt32(ds.Tables[0].Rows[i]["Time"].ToString()));

参数:state是传入定时调用的函数的参数,BeginRead是定时调用的方法名称,