稳扎稳打Silverlight(25) - 2.0线程之Thread, Timer, BackgroundWorker, ThreadPool

<UserControl x:Class="Silverlight20.Thread.Thread" 
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"> 
        <StackPanel HorizontalAlignment="Left" Margin="5"> 
         
                <TextBlock x:Name="txtMsg" /> 
         
        </StackPanel> 
</UserControl>

Thread.xaml.cs

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Net; 
using System.Windows; 
using System.Windows.Controls; 
using System.Windows.Documents; 
using System.Windows.Input; 
using System.Windows.Media; 
using System.Windows.Media.Animation; 
using System.Windows.Shapes; 
 
namespace Silverlight20.Thread 
{ 
        public partial class Thread : UserControl 
        { 
                string result = ""; 
 
                public Thread() 
                { 
                        InitializeComponent(); 
 
                        Demo(); 
                } 
 
                void Demo() 
                { 
                        /* 
                         * Thread - 用于线程的创建和控制的类 
                         *         Name - 线程名称 
                         *         IsBackground - 是否是后台线程（对于Silverlight来说，是否是后台线程没区别） 
                         *         Start(object parameter) - 启动后台线程 
                         *                 object parameter - 为后台线程传递的参数 
                         *         IsAlive - 线程是否在执行中 
                         *         ManagedThreadId - 当前托管线程的唯一标识符 
                         *         ThreadState - 指定线程的状态 [System.Threading.ThreadState枚举] 
                         *         Abort() - 终止线程 
                         */ 
 
                        // DoWork 是后台线程所执行的方法（此处省略掉了委托类型） 
                        // ThreadStart 委托不可以带参数, ParameterizedThreadStart 委托可以带参数 
                        System.Threading.Thread thread = new System.Threading.Thread(DoWork); 
                        thread.Name = "ThreadDemo"; 
                        thread.IsBackground = true; 
                        thread.Start(1000); 
 
                        result += thread.IsAlive + "\r\n"; 
                        result += thread.ManagedThreadId + "\r\n"; 
                        result += thread.Name + "\r\n"; 
                        result += thread.ThreadState + "\r\n"; 
 
                        // thread.Join(); 阻塞调用线程（本例为主线程），直到指定线程（本例为thread）执行完毕为止 
 
                        // 阻塞调用线程（本例为主线程） 
                        // 如果指定线程执行完毕则继续（本例为thread执行完毕则继续） 
                        // 如果指定线程运行的时间超过指定时间则继续（本例为thread执行时间如果超过5秒则继续） 
                        // 返回值为在指定时间内指定线程是否执行完毕（本例中thread的执行时间为1秒，所以会返回true）
                        if (thread.Join(5000))    
                        { 
                                result += "指定线程在5秒内执行完毕\r\n"; 
                        } 
 
                        txtMsg.Text = result; 
                } 
 
                void DoWork(object sleepMillisecond) 
                { 
                        System.Threading.Thread.Sleep((int)sleepMillisecond); 
 
                        result += "新开线程执行完毕\r\n"; 
                } 
        } 
}

2、Timer.xaml

<UserControl x:Class="Silverlight20.Thread.Timer" 
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"> 
        <StackPanel HorizontalAlignment="Left" Margin="5"> 
         
                <TextBlock x:Name="txtMsg" /> 
         
        </StackPanel> 
</UserControl>

Timer.xaml.cs

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Net; 
using System.Windows; 
using System.Windows.Controls; 
using System.Windows.Documents; 
using System.Windows.Input; 
using System.Windows.Media; 
using System.Windows.Media.Animation; 
using System.Windows.Shapes; 
 
namespace Silverlight20.Thread 
{ 
        public partial class Timer : UserControl 
        { 
                System.Threading.SynchronizationContext _syncContext; 
                // Timer - 用于以指定的时间间隔执行指定的方法的类 
                System.Threading.Timer _timer; 
                private int _flag = 0; 
 
                public Timer() 
                { 
                        InitializeComponent(); 
 
                        // UI 线程 
                        _syncContext = System.Threading.SynchronizationContext.Current; 
 
                        Demo(); 
                } 
 
                void Demo() 
                { 
                        // 输出当前时间 
                        txtMsg.Text = DateTime.Now.ToString() + "\r\n"; 
 
                        // 第一个参数：定时器需要调用的方法 
                        // 第二个参数：传给需要调用的方法的参数 
                        // 第三个参数：此时间后启动定时器 
                        // 第四个参数：调用指定方法的间隔时间（System.Threading.Timeout.Infinite 为无穷大） 
                        _timer = new System.Threading.Timer(MyTimerCallback, "webabcd", 3000, 1000); 
                } 
 
                private void MyTimerCallback(object state) 
                { 
                        string result = string.Format("{0} - {1}\r\n", DateTime.Now.ToString(), (string)state); 
 
                        // 调用 UI 线程。不会做自动线程同步 
                        _syncContext.Post(delegate { txtMsg.Text += result; }, null);    
 
                        _flag++; 
                        if (_flag == 5) 
                                _timer.Change(5000, 500); // 执行5次后，计时器重置为5秒后启动，每5毫秒的间隔时间执行一次指定的方法 
                        else if (_flag == 10) 
                                _timer.Dispose(); // 执行10次后，释放计时器所使用的全部资源 
                } 
        } 
}

3、BackgroundWorker.xaml

<UserControl x:Class="Silverlight20.Thread.BackgroundWorker" 
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"> 
        <StackPanel HorizontalAlignment="Left" Margin="5">

<StackPanel Orientation="Horizontal" Margin="5"> 
                        <Button x:Name="btnStart" Content="开始" Margin="5" Click="btnStart_Click" /> 
                        <Button x:Name="btnCancel" Content="取消" Margin="5" Click="btnCancel_Click" /> 
                </StackPanel> 
                 
                <StackPanel Margin="5"> 
                        <TextBlock x:Name="txtProgress" Margin="5" /> 
                        <TextBlock x:Name="txtMsg" Margin="5" /> 
                </StackPanel>

</StackPanel>    
</UserControl>

BackgroundWorker.xaml.cs

/* 
 * 演示用 BackgroundWorker 在后台线程上执行耗时的操作 
 * 按“开始”键，开始在后台线程执行耗时操作，并向UI线程汇报执行进度 
 * 按“取消”键，终止后台线程 
 * BackgroundWorker 调用 UI 线程时会自动做线程同步 
 */ 
 
using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Net; 
using System.Windows; 
using System.Windows.Controls; 
using System.Windows.Documents; 
using System.Windows.Input; 
using System.Windows.Media; 
using System.Windows.Media.Animation; 
using System.Windows.Shapes; 
 
namespace Silverlight20.Thread 
{ 
        public partial class BackgroundWorker : UserControl 
        { 
                // BackgroundWorker - 用于在单独的线程上运行操作。例如可以在非UI线程上运行耗时操作，以避免UI停止响应 
                System.ComponentModel.BackgroundWorker _backgroundWorker; 
 
                public BackgroundWorker() 
                { 
                        InitializeComponent(); 
 
                        BackgroundWorkerDemo(); 
                } 
 
                void BackgroundWorkerDemo() 
                { 
                        /* 
                         * WorkerSupportsCancellation - 是否支持在其他线程中取消该线程的操作 
                         * WorkerReportsProgress - 是否可以报告操作进度 
                         * ProgressChanged - 报告操作进度时触发的事件 
                         * DoWork - BackgroundWorker 调用 RunWorkerAsync() 方法时触发的事件。在此执行具体操作 
                         * RunWorkerCompleted - 操作完成/取消/出错时触发的事件 
                         */ 
 
                        _backgroundWorker = new System.ComponentModel.BackgroundWorker(); 
 
                        _backgroundWorker.WorkerSupportsCancellation = true; 
                        _backgroundWorker.WorkerReportsProgress = true; 
 
                        _backgroundWorker.ProgressChanged += new System.ComponentModel.ProgressChangedEventHandler(_backgroundWorker_ProgressChanged); 
                        _backgroundWorker.DoWork += new System.ComponentModel.DoWorkEventHandler(_backgroundWorker_DoWork); 
                        _backgroundWorker.RunWorkerCompleted += new System.ComponentModel.RunWorkerCompletedEventHandler(_backgroundWorker_RunWorkerCompleted); 
                } 
 
                private void btnStart_Click(object sender, RoutedEventArgs e) 
                { 
                        // IsBusy - 指定的 BackgroundWorker 是否正在后台操作 
                        // RunWorkerAsync(object argument) - 开始在后台线程执行指定的操作 
                        //         object argument - 需要传递到 DoWork 的参数 
                        if (!_backgroundWorker.IsBusy) 
                                _backgroundWorker.RunWorkerAsync("需要传递的参数"); 
                } 
 
                private void btnCancel_Click(object sender, RoutedEventArgs e) 
                { 
                        // CancelAsync() - 取消 BackgroundWorker 正在执行的后台操作 
                        if (_backgroundWorker.WorkerSupportsCancellation) 
                                _backgroundWorker.CancelAsync(); 
                } 
 
                void _backgroundWorker_DoWork(object sender, System.ComponentModel.DoWorkEventArgs e) 
                { 
                        /* 
                         * DoWorkEventArgs.Argument - RunWorkerAsync(object argument)传递过来的参数 
                         * DoWorkEventArgs.Cancel - 取消操作 
                         * DoWorkEventArgs.Result - 操作的结果。将传递到 RunWorkerCompleted 所指定的方法 
                         * BackgroundWorker.ReportProgress(int percentProgress, object userState) - 向 ProgressChanged 汇报操作的完成进度 
                         *         int percentProgress - 操作完成的百分比 1% - 100% 
                         *         object userState - 传递到 ProgressChanged 的参数 
                         */ 
 
                        for (int i = 0; i < 10; i++) 
                        { 
                                if ((_backgroundWorker.CancellationPending == true)) 
                                { 
                                        e.Cancel = true; 
                                        break; 
                                } 
                                else 
                                { 
                                        System.Threading.Thread.Sleep(1000); 
                                        _backgroundWorker.ReportProgress((i + 1) * 10, i); 
                                } 
                        } 
 
                        e.Result = "操作已完成"; 
                } 
 
                void _backgroundWorker_ProgressChanged(object sender, System.ComponentModel.ProgressChangedEventArgs e) 
                { 
                        // ProgressChangedEventArgs.ProgressPercentage - ReportProgress 传递过来的操作完成的百分比 
                        // ProgressChangedEventArgs.UserState - ReportProgress 传递过来的参数 
                        txtProgress.Text = string.Format("完成进度：{0}%；参数：{1}", 
                                e.ProgressPercentage, 
                                e.UserState); 
                } 
 
                void _backgroundWorker_RunWorkerCompleted(object sender, System.ComponentModel.RunWorkerCompletedEventArgs e) 
                { 
                        /* 
                         * RunWorkerCompletedEventArgs.Error - DoWork 时产生的错误 
                         * RunWorkerCompletedEventArgs.Cancelled - 后台操作是否已被取消 
                         * RunWorkerCompletedEventArgs.Result - DoWork 的结果 
                         */ 
 
                        if (e.Error != null) 
                        { 
                                txtMsg.Text += e.Error.ToString() + "\r\n"; 
                        } 
                        else if (e.Cancelled) 
                        { 
                                txtMsg.Text += "操作被取消\r\n"; 
                        } 
                        else 
                        { 
                                txtMsg.Text += e.Result.ToString() + "\r\n"; 
                        } 
                } 
        } 
}

4、ThreadPool.xaml

<UserControl x:Class="Silverlight20.Thread.ThreadPool" 
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"> 
        <StackPanel HorizontalAlignment="Left" Margin="5">

<TextBlock x:Name="txtMsgQueueUserWorkItem" Text="click here" MouseLeftButtonDown="txtMsgQueueUserWorkItem_MouseLeftButtonDown" Margin="30" />

<TextBlock x:Name="txtRegisterWaitForSingleObject" Text="click here" MouseLeftButtonDown="txtRegisterWaitForSingleObject_MouseLeftButtonDown" Margin="30" />

</StackPanel> 
</UserControl>

ThreadPool.xaml.cs

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Net; 
using System.Windows; 
using System.Windows.Controls; 
using System.Windows.Documents; 
using System.Windows.Input; 
using System.Windows.Media; 
using System.Windows.Media.Animation; 
using System.Windows.Shapes; 
 
namespace Silverlight20.Thread 
{ 
        public partial class ThreadPool : UserControl 
        { 
                public ThreadPool() 
                { 
                        InitializeComponent(); 
                } 
 
                private void txtMsgQueueUserWorkItem_MouseLeftButtonDown(object sender, MouseButtonEventArgs e) 
                { 
                        // ThreadPool - 线程池的管理类 
 
                        // QueueUserWorkItem(WaitCallback callBack, Object state) - 将指定方法加入线程池队列 
                        //         WaitCallback callBack - 需要在新开线程里执行的方法 
                        //         Object state - 传递给指定方法的参数 
                        System.Threading.ThreadPool.QueueUserWorkItem(DoWork, DateTime.Now); 
                } 
 
                private void DoWork(object state) 
                { 
                        // 作为线程管理策略的一部分，线程池在创建线程前会有一定的延迟 
                        // 也就是说线程入队列的时间和线程启动的时间之间有一定的间隔 
 
                        DateTime dtJoin = (DateTime)state; 
                        DateTime dtStart = DateTime.Now; 
                        System.Threading.Thread.Sleep(3000); 
                        DateTime dtEnd = DateTime.Now; 
 
                        // Dispatcher.BeginInvoke() - 在与 Dispatcher 相关联的线程上执行指定的操作。自动线程同步 
                        this.Dispatcher.BeginInvoke(() => 
                        { 
                                txtMsgQueueUserWorkItem.Text += string.Format("\r\n入队列时间{0} 启动时间{1} 完成时间{2}", 
                                        dtJoin.ToString(), dtStart.ToString(), dtEnd.ToString()); 
                        }); 
                } 
 
 
                private void txtRegisterWaitForSingleObject_MouseLeftButtonDown(object sender, MouseButtonEventArgs e) 
                { 
                        System.Threading.AutoResetEvent done = new System.Threading.AutoResetEvent(false); 
 
                        // 为了传递 RegisteredWaitHandle 对象，要将其做一个封装 
                        RegisteredWaitHandlePacket packet = new RegisteredWaitHandlePacket(); 
 
                        // RegisterWaitForSingleObject - 注册一个 WaitHandle 。在超时或发信号的情况下对指定的回调方法做调用 
                        // 第一个参数：需要注册的 WaitHandle 
                        // 第二个参数：需要回调的方法（此处省略掉了委托类型） 
                        // 第三个参数：传递给回调方法的参数 
                        // 第四个参数：超时时间（到超时时间则调用指定的方法） 
                        // 第五个参数：是否为一次调用（是到超时时间一次性调用指定的方法，还是每次超时时间后都调用指定的方法） 
                        packet.Handle = System.Threading.ThreadPool.RegisterWaitForSingleObject 
                                ( 
                                        done, 
                                        WaitOrTimer, 
                                        packet, 
                                        100, 
                                        false 
                                ); 
 
                        System.Threading.Thread.Sleep(555); 
                        done.Set(); // 发出信号，调用 RegisterWaitForSingleObject 所指定的方法 
                } 
 
                public void WaitOrTimer(object state, bool timedOut) 
                { 
                        RegisteredWaitHandlePacket packet = state as RegisteredWaitHandlePacket; 
 
                        // bool timedOut - 是否是因为超时而执行到这里 
                        if (!timedOut)    
                        { 
                                // 如果不是因为超时而执行到这里（即因为 AutoResetEvent 发出了信号而执行到这里），则注销指定的 RegisteredWaitHandle 
                                packet.Handle.Unregister(null); 
                        } 
 
                        this.Dispatcher.BeginInvoke(() => 
                        { 
                                txtRegisterWaitForSingleObject.Text += 
                                        String.Format("\r\n是否收到信号：{0}", (!timedOut).ToString()); 
                        }); 
                } 
        } 
 
        /// <summary> 
        /// 封装了 RegisteredWaitHandle 的类 
        /// </summary> 
        public class RegisteredWaitHandlePacket 
        { 
                public System.Threading.RegisteredWaitHandle Handle { get; set; } 
        } 
}

OK
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本文转自webabcd 51CTO博客，原文链接：http://blog.51cto.com/webabcd/343906，如需转载请自行联系原作者