线程入门
创建线程
using system;
using system.Threading;
ThreadStart entry = new ThreadStart(CalcSum);
Thread workThread = new Thread(entry);
//or
Thread workThread = new Thread(new ThreadStart(CalcSum));
//Method：
static void CalcSum()
{
//do somethings.
}
Thread类几个重要方法
Thread类用于创建线程，ThreadPool类用于管理线程池。
Thread类中几个重要的方法： 1. Start()：启动线程； 2. Sleep(int)：静态方法，暂停当前线程指定的毫秒数； 3. Abort()：通常使用该方法来终止一个线程； 4. Suspend()：该方法并不终止未完成的线程，它仅仅挂起线程，以后还可恢复； 5. Resume()：恢复被Suspend()方法挂起的线程的执行。
Thread.ThreadState属性
Thread.ThreadState 在各种情况下的取值如下： 1. Aborted：线程已停止 2. AbortRequested：线程的Thread.Abort()方法已被调用，但是线程还未停止 3. Background：线程在后台执行，与属性Thread.IsBackground有关(前台所有进程) 4. Running：线程正在正常运行 5. Stopped：线程已经被停止 6. StopRequested：线程正在被要求停止 7. Suspended：线程已经被挂起（此状态下，可以通过调用Resume()方法重新运行） 8. SuspendRequested：线程正在要求被挂起，但是未来得及响应 9. Unstarted：未调用Thread.Start()开始线程的运行 10. WaitSleepJoin：线程因为调用了Wait(),Sleep()或Join()等方法处于封锁状态
设定线程优先级
优先级由高到低分别是Highest，AboveNormal，Normal，BelowNormal，Lowest。默认为ThreadPriority.Normal。
//示例：设定优先级为最低 myThread.Priority=ThreadPriority.Lowest;
线程的同步和通讯——生产者和消费者
假设这样一种情况，两个线程同时维护一个队列，如果一个线程对队列中添加元素，而另外一个线程从队列中取用元素，那么我们称添加元素的线程为生产者，称取用元素的线程为消费者。
lock关键字
lock 关键字解决多个线程同时执行一个函数，导致数据的混乱，产生不可预料的结果的问题。 lock 关键字将一段代码定义为互斥段（critical section）。互斥段在一个时刻内只允许一个线程进入执行，而其他线程必须等待。
//定义如下： lock(expression) statement_block //expression代表你希望跟踪的对象，通常是对象引用。一般地，保护一个类的实例，可以使用this；保护一个静态变量（如互斥代码段在一个静态方法内部），一般使用类名就可以。 //statement_block就是互斥段的代码，这段代码在一个时刻内只可能被一个线程执行。
Monitor类(System.Threading)
Monitor提供了使线程共享资源的方案。 Monitor类可以锁定一个对象，一个线程只有得到这把锁才可以对该对象进行操作。
...... Queue oQueue=new Queue(); ...... Monitor.Enter(oQueue); ......//现在oQueue对象只能被当前线程操纵了 Monitor.Exit(oQueue);//释放锁 //为了保证线程最终都能释放锁，你可以把Monitor.Exit()方法写在try-catch-finally结构中的finally代码块里。 //当拥有对象锁的线程准备释放锁时，它使用Monitor.Pulse()方法通知等待队列中的第一个线程。
Monitor.Wait()和Monitor.Pulse()
1. Wait()就是交出锁的使用权，使线程处于阻塞状态，直到再次获得锁的使用权。 2. 当前线程调用Pulse()向队列中的下一个线程发出锁的信号。接收到脉冲后，等待线程就被移动到就绪队列中。 在调用 Pulse 的线程释放锁后，就绪队列中的下一个线程（不一定是接收到脉冲的线程）将获得该锁。pulse()并不会使当前线程释放锁。
实例：开辟一线程实现异步导出Excel
环境介绍及实例简述
环境介绍： 开发语言》C#; 开发工具》Visual studio 2015; Asp.Net MVC Version》5.2.3; .Net Version》6.1.3; NIPO version》2.2.1;
实例简述： 由于导出的Excel文件比较大，非常耗时，为了不影响对界面的其他操作，需要采用异步的方式进行导出。 具体实现方法就是后台开辟一个线程将Excel导出到指定目录，然后提供下载。
实现思路及准备工作
思路： 通过线程实现异步导出操作； 通过NIPO组件将数据存到Excel文件中。
准备工作： 1.下载NPOI组件，http://npoi.codeplex.com/ 2.orcleHelper.dll
实例代码
UserController.cs
using Project.BLL;
using Project.Class;
using Project.Interface;
using Project.ViewModel;
using System;
using System.Collections.Generic;
using System.IO;
using System.Web.Mvc;
using System.Web.Script.Serialization;
namespace Project.UI
{
/// <summary>
/// 文件信息类
/// </summary>
public class FileInfoClass
{
public int count { set; get; }
public IList<string> d_fileList { set; get; }
}
/// <summary>
/// 用户控制器
/// </summary>
public class UserController : BaseController
{
//用户接口
private IUserBLL iuser = new UserBLL();
//返回信息
private ReturnInfo returninfo = new ReturnInfo();
/// <summary>
/// 导出用户数据，返回文件列表
/// </summary>
public ActionResult UserInfoExportExcel()
{
//搜索条件Model对象
SearchUserModel searchUserModel = new SearchUserModel();
//1.获取数据(具体如何获取数据，这里没有陈述)
List<UserViewModel> list = iuser.GetUserInfo(searchUserModel, ref returninfo) as List<UserViewModel>;
//2.调用方法，导出Excel
//生成文件名称（改文件名称）
var fileName = string.Format("{0}用户信息表.xls", DateTime.Now.ToString("yyyyMMddHHssmm"));
//判断目录是否存在（该目录名称）
if (!Directory.Exists(Server.MapPath("~/Downloads/用户信息")))
{
Directory.CreateDirectory(Server.MapPath("~/Downloads/用户信息"));
}
//将生成的文件保存到服务器临时文件夹中
string fullPath = Path.Combine(Server.MapPath("~/Downloads/用户信息"), fileName);
//表头
Dictionary<string, string> tableHeader = new Dictionary<string, string>
{
{ "user_id","用户编号" },
{ "username","用户名" },
{ "sex","性别" },
{ "age","年龄" },
{ "tel","联系电话"},
{ "email","邮箱"},
{ "user_type", "用户类型" },
{ "nickname", "用户昵称" }
};
//导出到Excel。(Global.asax.cs)
MvcApplication._VehicleQueueT.Enqueue(new Classes.DataExportPara { excelPath=fullPath, sheetName = "用户信息", tableHeard= tableHeader, list =list});
//获取路径
string path = Server.MapPath("~/Downloads/用户信息");
//获取所有xls文件路径
IList<string> fileList = GetAllFileName(path);
FileInfoClass f_info = new FileInfoClass();
f_info.count = fileList.Count;
f_info.d_fileList = fileList;
//返回文件列表
return new ContentResult
{
Content = new JavaScriptSerializer { MaxJsonLength = Int32.MaxValue }.Serialize(f_info),
ContentType = "application/json"
};
}
/// <summary>
/// 仅获取文件列表
/// </summary>
/// <returns></returns>
public ActionResult GetFileLists()
{
if (!Directory.Exists(Server.MapPath("~/Downloads/用户信息")))
{
Directory.CreateDirectory(Server.MapPath("~/Downloads/用户信息"));
}
//路径
string path = Server.MapPath("~/Downloads/用户信息");
//
IList<string> fileList = GetAllFileName(path);
FileInfoClass f_info = new FileInfoClass();
f_info.count = fileList.Count;
f_info.d_fileList = fileList;
return new ContentResult
{
Content = new JavaScriptSerializer { MaxJsonLength = Int32.MaxValue }.Serialize(f_info),
ContentType = "application/json"
};
}
/// <summary>
/// 删除文件
/// </summary>
/// <param name="fileName"></param>
/// <returns></returns>
public ActionResult DeleteFile(string fileName)
{
string result = "";
//路径
string filePath = Server.MapPath("~/Downloads/用户信息/"+fileName);
if (!Directory.Exists(Server.MapPath("~/Downloads/已删除文件目录")))
{
Directory.CreateDirectory(Server.MapPath("~/Downloads/已删除文件目录"));
}
string deletedFilePath = Server.MapPath("~/Downloads/已删除文件目录/"+fileName);
try
{
//System.IO.File.Delete(filePath);
//移动文件到"已删除文件目录"中
FileInfo file = new FileInfo(filePath);
file.MoveTo(deletedFilePath);
result += "成功删除文件";
}
catch (Exception)
{
result += "删除文件失败";
}
//返回操作结果
return Json(result, JsonRequestBehavior.AllowGet);
}
/// <summary>
/// 获取目录下的所有xls文件
/// </summary>
/// <param name="path"></param>
/// <returns></returns>
private IList<string> GetAllFileName(string path)
{
/*List<FileInfo> filelist = new List<FileInfo>();
//if (System.IO.File.Exists(path+"\\*.xls"))
var files = Directory.GetFiles(path, "*.xls");
foreach (var file in files)
{
filelist.Add(new FileInfo(file));
}*/
IList<string> list = new List<string>();
DirectoryInfo folder = new DirectoryInfo(path);
foreach (FileInfo file in folder.GetFiles("*.xls"))
{
list.Add(file.Name);
}
return list;
}
}
}
Global.asax.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Web;
using System.Web.Mvc;
using System.Web.Optimization;
using System.Web.Routing;
using Project.Classes;
namespace GpsProject.UI
{
public class MvcApplication : System.Web.HttpApplication
{
//数据导出队列
public static Queue<DataExportPara> _VehicleQueueT = new Queue<DataExportPara>();
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
OutputVehicleExcel();//注册信息导出方法
}
/// <summary>
/// 导出信息
/// </summary>
public static void OutputVehicleExcel()
{
DataExportPara exportPara = null;
ThreadPool.QueueUserWorkItem(o =>
{
while (true)
{
if (_VehicleQueueT != null && _VehicleQueueT.Count > 0)
{
exportPara = _VehicleQueueT.Dequeue();
if (exportPara != null)
{
//调用方法
DataExport.ExportExcel(exportPara.excelPath, exportPara.sheetName, exportPara.tableHeard, exportPara.list);
}
else
{
Thread.Sleep(6000);
}
}
else
{
Thread.Sleep(6000);
}
}
});
}
}
}
DataExportPara.cs
using System.Collections;
using System.Collections.Generic;
namespace Project.Classes
{
/// <summary>
/// 数据导出para
/// </summary>
public class DataExportPara
{
/// <summary>
/// 导出路径
/// </summary>
public string excelPath { get; set; }
/// <summary>
/// 数据列表
/// </summary>
public IList list { get; set; }
/// <summary>
/// 工作表名称
/// </summary>
public string sheetName { get; set; }
/// <summary>
/// 表头
/// </summary>
public Dictionary<string, string> tableHeard {get;set;}
}
}
DataExport.cs
using GpsProject.Class;
using System.Collections;
using System.Collections.Generic;
using System.IO;
namespace Project.Classes
{
/// <summary>
/// 数据导出
/// </summary>
public class DataExport
{
/// <summary>
/// 导出Excel到目录
/// </summary>
/// <param name="path"></param>
/// <param name="sheetName"></param>
/// <param name="tableHeard"></param>
/// <param name="list"></param>
public static void ExportExcel(string path, string sheetName, Dictionary<string, string> tableHeard, IList list)
{
using (var exportData = NPOIExcelHelper.ExportToExcelStream(list, sheetName, tableHeard))
{
//创建一个文件
FileStream file = new FileStream(path, FileMode.Create, FileAccess.Write);
exportData.WriteTo(file);
file.Close();
}
}
}
}
NPOIExcelHelper.cs
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using NPOI.SS.UserModel;
using System.Collections;
namespace Project.Class
{
/// <summary>
/// NPOI
/// </summary>
public class NPOIExcelHelper
{
/// <summary>
/// 导出Excel到文件流
/// </summary>
/// <param name="dt"></param>
/// <param name="sheetName"></param>
/// <param name="tableHeard"></param>
/// <returns>文件流</returns>
public static MemoryStream ExportToExcelStream(IList lists, string sheetName, Dictionary<string, string> tableHeard)
{
//创建一个工作簿
NPOI.HSSF.UserModel.HSSFWorkbook book = new NPOI.HSSF.UserModel.HSSFWorkbook();
NPOI.SS.UserModel.ISheet sheet = book.CreateSheet(sheetName); //创建sheet
//Excel表头
NPOI.SS.UserModel.IRow row = sheet.CreateRow(0); //创建行
ICellStyle style = book.CreateCellStyle(); //创建单元格
style.Alignment = HorizontalAlignment.Center; //对齐方式
style.VerticalAlignment = VerticalAlignment.Center; //单元格居中对齐
#region 设置表头
List<string> headers = tableHeard.Keys.ToList();
for (int i = 0; i < headers.Count; i++)
{
ICell cell = row.CreateCell(i);
cell.CellStyle = style;
cell.SetCellValue(tableHeard[headers[i]]);
}
/*for (int i = 0; i < dt.Columns.Count; i++)
{
ICell cell = row.CreateCell(i);
cell.CellStyle = style;
cell.SetCellValue(dt.Columns[i].ColumnName);
}*/
#endregion
#region 填充数据
int rowIndex = 1;// 从第二行开始赋值(第一行已设置为单元头)
if (lists != null && lists.Count > 0)
{
foreach (var list in lists)
{
IRow rowTemp = sheet.CreateRow(rowIndex);
for (int i = 0; i < headers.Count; i++)
{
string cellValue = ""; // 单元格的值
object properotyValue = null; // 属性的值
System.Reflection.PropertyInfo properotyInfo = null; // 属性的信息
if (headers[i].IndexOf(".") > 0)
{
// 3.1.1 解析子类属性(这里只解析1层子类，多层子类未处理)
string[] properotyArray = headers[i].Split(new string[] { "." }, StringSplitOptions.RemoveEmptyEntries);
string subClassName = properotyArray[0]; // '.'前面的为子类的名称
string subClassProperotyName = properotyArray[1]; // '.'后面的为子类的属性名称
System.Reflection.PropertyInfo subClassInfo = list.GetType().GetProperty(subClassName); // 获取子类的类型
if (subClassInfo != null)
{
// 3.1.2 获取子类的实例
var subClassEn = list.GetType().GetProperty(subClassName).GetValue(list, null);
// 3.1.3 根据属性名称获取子类里的属性类型
properotyInfo = subClassInfo.PropertyType.GetProperty(subClassProperotyName);
if (properotyInfo != null)
{
properotyValue = properotyInfo.GetValue(subClassEn, null); // 获取子类属性的值
}
}
}
else
{
// 3.2 若不是子类的属性，直接根据属性名称获取对象对应的属性
properotyInfo = list.GetType().GetProperty(headers[i]);
if (properotyInfo != null)
{
properotyValue = properotyInfo.GetValue(list, null);
}
}
// 3.3 属性值经过转换赋值给单元格值
if (properotyValue != null)
{
cellValue = properotyValue.ToString();
// 3.3.1 对时间初始值赋值为空
if (cellValue.Trim() == "0001/1/1 0:00:00" || cellValue.Trim() == "0001/1/1 23:59:59")
{
cellValue = "";
}
}
// 3.4 填充到Excel的单元格里
ICell icellcontent = rowTemp.CreateCell(i);
//icellcontent.CellStyle = Getcellstyle(workbook, cellStylecontent, fontcontent, stylexls.默认);
icellcontent.SetCellValue(cellValue);
}
rowIndex++;
//达到65535行，跳出循环
if (rowIndex== 65535)
{
break;
}
}
}
else
{
//导出空数据
sheet.AddMergedRegion(new NPOI.SS.Util.CellRangeAddress(2, 2, 0, headers.Count - 1));
IRow row2 = sheet.CreateRow(1);
ICell icellkong = row2.CreateCell(0);
// icellkong.CellStyle = Getcellstyle(workbook, stylexls.默认);
string str = "没有满足条件的数据可导出";
icellkong.SetCellValue(str);
}
/* for (int i = 1; i <= dt.Rows.Count; i++)//遍历DataTable行
{
DataRow dataRow = dt.Rows[i - 1];
row = sheet.CreateRow(i);//在工作表中添加一行
for (int j = 0; j < dt.Columns.Count; j++)//遍历DataTable列
{
ICell cell = row.CreateCell(j);//在行中添加一列
cell.SetCellValue(dataRow[j].ToString());//设置列的内容
}
}*/
#endregion
MemoryStream ms = new MemoryStream();
book.Write(ms);
return ms; //返回文件流
}
}
}
小结
在阅读别人的文章时，认真。
实例：利用线程监听模拟车辆进出智能化停车场
实例简述
实现效果
主要代码
Main.cs
private void Main_Load(object sender, EventArgs e)
{
MessagePrint.UpdateEventInfo += new MessagePrint.ShowEventInfoHandler(UpdateRuntimeInfo);
//设置开始、结束时间为00:00:00
dateTimePicker_InStart.Text = ConfigInfoHelper.InStartRunTime;
dateTimePicker_InEnd.Text = ConfigInfoHelper.InEndRunTime;
dateTimePicker_OutStart.Text = ConfigInfoHelper.OutStartRunTime;
dateTimePicker_OutEnd.Text = ConfigInfoHelper.OutEndRunTime;
//获取默认时间
BTModel.InStartRunTime = ConfigInfoHelper.InStartRunTime;
BTModel.InEndRunTime = ConfigInfoHelper.InEndRunTime;
BTModel.OutStartRunTime = ConfigInfoHelper.OutStartRunTime;
BTModel.OutEndRunTime = ConfigInfoHelper.OutEndRunTime;
vehicleio = new VehicleIO(BTModel);
vehicleio.StartServer();
}
/// <summary>
/// 应用更改
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void ApplyChanged_Click(object sender, EventArgs e)
{
//先停止监听线程
vehicleio.StopServer();
BTModel.InStartRunTime = dateTimePicker_InStart.Text;
BTModel.InEndRunTime = dateTimePicker_InEnd.Text;
BTModel.OutStartRunTime = dateTimePicker_OutStart.Text;
BTModel.OutEndRunTime = dateTimePicker_OutEnd.Text;
vehicleio = new VehicleIO(BTModel);
vehicleio.StartServer();
}
VehicleIO.cs
private string InStartRunTime="";//园区进场开启时间 private string InEndRunTime = "";//园区进场结束时间 private string OutStartRunTime = "";//园区出场开启时间 private string OutEndRunTime = "";//园区出场结束时间 public VehicleIO(RunTimeModel btModel) { InStartRunTime = btModel.InStartRunTime; InEndRunTime = btModel.InEndRunTime; OutStartRunTime = btModel.OutStartRunTime; OutEndRunTime = btModel.OutEndRunTime; } private Thread thread = null; //初始值 private int sendLocationInterval = 3; //new 车辆进出园区数据模型 private VehicleIOModel iomodel = new VehicleIOModel(); /// <summary> /// 开始服务 /// </summary> public void StartServer() { ThreadStart iothread = new ThreadStart(working); thread = new Thread(iothread); thread.Start(); } /// <summary> /// 停止服务 /// </summary> public void StopServer() { if (thread != null && thread.IsAlive) { thread.Abort(); } } /// <summary> /// 挂起服务 /// </summary> public void SuspendServer() { if (thread.ThreadState == ThreadState.Running) { thread.Suspend(); } } /// <summary> /// 恢复服务 /// </summary> public void ResumeServer() { if (thread.ThreadState == ThreadState.Suspended) { thread.Resume(); } }
/// <summary>
/// work.
/// </summary>
private void working()
{
MessagePrint.SendEventInfo(1, true, "园区进出场系统开启!");
while (true)
{
#region 进园区
if (DateTime.Now.ToLongTimeString().Equals(InStartRunTime))
{
MessagePrint.SendEventInfo(1, true, "园区入场道口开启，车辆开始进入园区！");
DataTable dtVehicleInInfo = null;
try
{
//获取未入场的卡号
dtVehicleInInfo = VehicleIODal.GetInstance().GetVehicleCardInInfo();
}
catch (Exception exc)
{
MessagePrint.SendEventInfo(1, true, "未能查询到数据，请检查数据库连接串" + exc);
}
if (dtVehicleInInfo.Rows.Count > 0)
{
MessagePrint.SendEventInfo(1, true, "已查询到所有可以进入园区的车辆数据，正在准备进入园区……");
for (int i = 0; i < dtVehicleInInfo.Rows.Count; i++)
{
string cardNo = dtVehicleInInfo.Rows[i]["card_no"].ToString();
MessagePrint.SendEventInfo(1, true, "卡号为“" + cardNo + "”的车辆，正在进入园区……");
//这里记录进入信息...略
//
//获取一个随机数(min 20,max 200,number 1)
int rand = Convert.ToInt32(getRandom(20, 150, 1));
MessagePrint.SendEventInfo(1, true, "下一辆车辆将在" + sendLocationInterval * rand / 60 + "分钟后抵达园区");
if (DateTime.Now.ToLongTimeString().Equals(InEndRunTime) || DateTime.Now.ToLongTimeString().CompareTo(InEndRunTime) > 0)
{
MessagePrint.SendEventInfo(1, true, "园区入场道口关闭，停止车辆入场！入场道口将会在 " + InStartRunTime + " 再次开启！");
break;
}
else
{
Thread.Sleep(sendLocationInterval * 1000 * rand);
}
}
MessagePrint.SendEventInfo(1, true, "注意：车辆进入园区操作完成！");
}
else
{
MessagePrint.SendEventInfo(1, true, "目前没有查询到要进入园区的车辆。");
}
}
#endregion
#region 出园区
//与进园区代码一致，略
#endregion
}
}
其他
//显示实时时间
#region 运行时显示实时时间
new Thread(() =>
{
while (true)
{
try
{
labelTime.BeginInvoke(new MethodInvoker(() => labelTime.Text = DateTime.Now.ToString()));
}
catch (Exception)
{
}
Thread.Sleep(1000);
}
})
{ IsBackground = true }.Start();
#endregion
//随机数获取
/// <summary> /// 获取规定范围内的n个随机数 /// </summary> /// <param name="min_value">随机数下限</param> /// <param name="max_value">随机数上限</param> /// <param name="number">随机数量</param> /// <returns></returns> private string getRandom(int min_value, int max_value, int number) { Random random = new Random(); ArrayList arr = new ArrayList(); int temp = 0; for (int i = 0; i < number; i++) { temp = random.Next(min_value, max_value); //随机取数 arr.Add(temp); } string str = ""; for (int j = 0; j < arr.Count; j++) { str += arr[j].ToString() + ","; } return str.Substring(0, str.LastIndexOf(",")); }
参考资料
http://www.cnblogs.com/StupidsCat/archive/2013/01/05/2845505.html