一个关于多线程的问题

[bbjiabcd]

我要在WinForm里实现这样一个功能：点击一个按钮，程序创建一个新后台线程，处理一个需要一定时间的任务（比如：发电子邮件或者复制文件等），此时，主窗体不能没有响应。处理完后，返回操作结果，主窗体显示处理结果。在处理时，主窗体能显示处理进度更好。
最好能提供示例代码。本人菜鸟，望赐教。

[bdmh]

        private delegate void SetProgressBar(int value);
        private void SetPBar(int value)
        {
            if (this.InvokeRequired)
                this.Invoke(new Action<int>(SetPBar), value);
            else
            {
                this.progressBar1.Value = value;
            }
        }
        private void SetValue()
        {
            SetProgressBar setbar = new SetProgressBar(SetPBar);
            for (int i = 0; i < 100000; i++)
            {
                setbar.Invoke(i);
            }
        }
        private void button10_Click(object sender, EventArgs e)
        {
            progressBar1.Maximum = 100000;
            Thread thread = new Thread(new ThreadStart(SetValue));
            thread.Start();
        }

[bbjiabcd]

前2个函数和第一行的声明，能解释一下吗？

[bigbaldy]

private void button1_Click(object sender, EventArgs e)
{
new Thread(() =>
{
for(int i=0;i<10000;i++)
{
Invoke((MethodInvoker)(() => { progressBar1.Value = i; }));
}
}).Start();
}

[SocketUpEx]

拷贝文件的例子

类代码:
using System;
using System.IO;
using System.Runtime.InteropServices;
using System.Threading;

namespace WindowsFormsApplication1
{
    /// <summary>
    /// 继续滥用委托
    /// </summary>
    /// <param name="sourceFile"></param>
    /// <param name="targetFile"></param>
    public delegate void CopyProgressHandler(String sourceFile, String targetFile);

    /// <summary>
    /// 拷贝文件夹类
    /// </summary>
    public class CopyDirectory
    {
        /// <summary>
        /// 继续滥用事件
        /// </summary>
        public event CopyProgressHandler CopyProgress;

        #region Win32 API

        private const int MAX_PATH = 260;
        private const int MAX_ALTERNATE = 14;

        [StructLayout(LayoutKind.Sequential)]
        private struct FILETIME
        {
            public uint dwLowDateTime;
            public uint dwHighDateTime;
        };

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
        private struct WIN32_FIND_DATA
        {
            public FileAttributes dwFileAttributes;
            public FILETIME ftCreationTime;
            public FILETIME ftLastAccessTime;
            public FILETIME ftLastWriteTime;
            public uint nFileSizeHigh; //changed all to uint from int, otherwise you run into unexpected overflow
            public uint nFileSizeLow;  //| http://www.pinvoke.net/default.aspx/Structures/WIN32_FIND_DATA.html
            public uint dwReserved0;   //|
            public uint dwReserved1;   //v
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = MAX_PATH)]
            public string cFileName;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = MAX_ALTERNATE)]
            public string cAlternate;
        }

        [DllImport("kernel32", CharSet = CharSet.Unicode)]
        private static extern IntPtr FindFirstFile(string lpFileName, out WIN32_FIND_DATA lpFindFileData);

        [DllImport("kernel32", CharSet = CharSet.Unicode)]
        private static extern bool FindNextFile(IntPtr hFindFile, out WIN32_FIND_DATA lpFindFileData);

        [DllImport("kernel32.dll", SetLastError = true)]
        private static extern bool FindClose(IntPtr hFindFile);

        #endregion

        /// <summary>
        /// 拷贝
        /// </summary>
        /// <param name="sourceDirectory">源文件</param>
        /// <param name="targetDirectory">目标文件夹</param>
        public void Copy(String sourceDirectory, String targetDirectory)
        {
            IntPtr INVALID_HANDLE_VALUE = new IntPtr(-1);
            WIN32_FIND_DATA findData;

            IntPtr findHandle;

            findHandle = FindFirstFile(sourceDirectory + "*.*", out findData);
            if (findHandle != INVALID_HANDLE_VALUE)
            {
                do
                {
                    if ((findData.dwFileAttributes & FileAttributes.Directory) != 0)
                    {
                        if (findData.cFileName != "." && findData.cFileName != "..")
                        {
                            Copy(String.Format("{0}{1}{2}", sourceDirectory, findData.cFileName, "\\"), targetDirectory);
                        }
                    }
                    else
                    {
                        String strFile = sourceDirectory + findData.cFileName;
                        if (File.Exists(strFile))
                        {
                            try
                            {
                                FileInfo fileInfo = new FileInfo(strFile);
                                String strCopyTargetFile = String.Format("{0}{1}", targetDirectory, fileInfo.Name);
                                if (CopyProgress != null)
                                {
                                    // 触发事件,通知界面
                                    CopyProgress(strFile, strCopyTargetFile);
                                }
                                // 拷贝文件
                                File.Copy(strFile, strCopyTargetFile);
                            }
                            catch
                            {
                            }
                        }
                    }
                }
                while (FindNextFile(findHandle, out findData));
                FindClose(findHandle);
            }
        }
    }
}

窗体代码:

using System;
using System.IO;
using System.Runtime.InteropServices;
using System.Threading;

namespace WindowsFormsApplication1
{
    /// <summary>
    /// 继续滥用委托
    /// </summary>
    /// <param name="sourceFile"></param>
    /// <param name="targetFile"></param>
    public delegate void CopyProgressHandler(String sourceFile, String targetFile);

    /// <summary>
    /// 拷贝文件夹类
    /// </summary>
    public class CopyDirectory
    {
        /// <summary>
        /// 继续滥用事件
        /// </summary>
        public event CopyProgressHandler CopyProgress;

        #region Win32 API

        private const int MAX_PATH = 260;
        private const int MAX_ALTERNATE = 14;

        [StructLayout(LayoutKind.Sequential)]
        private struct FILETIME
        {
            public uint dwLowDateTime;
            public uint dwHighDateTime;
        };

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
        private struct WIN32_FIND_DATA
        {
            public FileAttributes dwFileAttributes;
            public FILETIME ftCreationTime;
            public FILETIME ftLastAccessTime;
            public FILETIME ftLastWriteTime;
            public uint nFileSizeHigh; //changed all to uint from int, otherwise you run into unexpected overflow
            public uint nFileSizeLow;  //| http://www.pinvoke.net/default.aspx/Structures/WIN32_FIND_DATA.html
            public uint dwReserved0;   //|
            public uint dwReserved1;   //v
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = MAX_PATH)]
            public string cFileName;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = MAX_ALTERNATE)]
            public string cAlternate;
        }

        [DllImport("kernel32", CharSet = CharSet.Unicode)]
        private static extern IntPtr FindFirstFile(string lpFileName, out WIN32_FIND_DATA lpFindFileData);

        [DllImport("kernel32", CharSet = CharSet.Unicode)]
        private static extern bool FindNextFile(IntPtr hFindFile, out WIN32_FIND_DATA lpFindFileData);

        [DllImport("kernel32.dll", SetLastError = true)]
        private static extern bool FindClose(IntPtr hFindFile);

        #endregion

        /// <summary>
        /// 拷贝
        /// </summary>
        /// <param name="sourceDirectory">源文件</param>
        /// <param name="targetDirectory">目标文件夹</param>
        public void Copy(String sourceDirectory, String targetDirectory)
        {
            IntPtr INVALID_HANDLE_VALUE = new IntPtr(-1);
            WIN32_FIND_DATA findData;

            IntPtr findHandle;

            findHandle = FindFirstFile(sourceDirectory + "*.*", out findData);
            if (findHandle != INVALID_HANDLE_VALUE)
            {
                do
                {
                    if ((findData.dwFileAttributes & FileAttributes.Directory) != 0)
                    {
                        if (findData.cFileName != "." && findData.cFileName != "..")
                        {
                            Copy(String.Format("{0}{1}{2}", sourceDirectory, findData.cFileName, "\\"), targetDirectory);
                        }
                    }
                    else
                    {
                        String strFile = sourceDirectory + findData.cFileName;
                        if (File.Exists(strFile))
                        {
                            try
                            {
                                FileInfo fileInfo = new FileInfo(strFile);
                                String strCopyTargetFile = String.Format("{0}{1}", targetDirectory, fileInfo.Name);
                                if (CopyProgress != null)
                                {
                                    // 触发事件,通知界面
                                    CopyProgress(strFile, strCopyTargetFile);
                                }
                                // 拷贝文件
                                File.Copy(strFile, strCopyTargetFile);
                            }
                            catch
                            {
                            }
                        }
                    }
                }
                while (FindNextFile(findHandle, out findData));
                FindClose(findHandle);
            }
        }
    }
}

[bigbaldy]

[Quote=引用 4 楼 的回复:]

拷贝文件的例子


C# code


类代码:
using System;
using System.IO;
using System.Runtime.InteropServices;
using System.Threading;

namespace WindowsFormsApplication1
{
/// <summary>
/// 继续滥用委托
//……
[/Quote]

你不如直接用C写了

[SocketUpEx]

[Quote=引用 5 楼 的回复:]
你不如直接用C写了
[/Quote]

不要这样喂
不要这样喂
Directory.GetFiles太垃圾了
竟然不是异步的
文件一多
就有可能卡死界面
有木有?
有木有?

[SocketUpEx]

尼玛
吃了饭重看这张帖
才发现
我给的代码根本不是多线程
是委托事件的例子

[bbjiabcd]

可能上面的问题表述不够清楚,我再重新说下
private void SendEmail()
{
try
{
client.Send(msg);
tSSlblStatus.Text = "发送完成";
MessageBox.Show("发送成功", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
catch (Exception ex)
{
tSSlblStatus.Text = "发送失败";
MessageBox.Show(ex.Message, "发送邮件出错", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
}
tSSlblStatus.Text = "";
txtReceive.Enabled = true; //这几句设置Enable的语句会出错
txtTitle.Enabled = true;
txtNeirong.Enabled = true;
btSend.Enabled = true;
btSettings.Enabled = true;
cByxj.Enabled = true;
}

private void btSend_Click(object sender, EventArgs e)
{
tSSlblStatus.Text = "准备发送...";
txtReceive.Enabled = false;
txtTitle.Enabled = false;
txtNeirong.Enabled = false;
btSend.Enabled = false;
btSettings.Enabled = false;
cByxj.Enabled = false;
...
Thread thread = new Thread(new ThreadStart(SendEmail));
tSSlblStatus.Text = "正在发送邮件...";
thread.Start();
}

这是我编的发送电子邮件的例子。线程结束前，需要将发送成功，或者失败的信息传送给主窗体，将MessageBox显示和改变控件Text、Enable的代码移到主窗体中，最好能将这些代码放进一个新的方法中，当主窗体收到线程的消息时执行这个方法。

[SocketUpEx]

public Form1()
{
InitializeComponent();
Control.CheckForIllegalCrossThreadCalls = false;
}

加上CheckForIllegalCrossThreadCalls = false就行了

[bbjiabcd]

现在网上很多关于 线程间通信 的资料都讲的是：如何子线程来控制UI中的控件。
而我要问的是：1、如何给线程传递一个参数，难道必须用全局变量？
2、如何在线程返回时，传递一个参数给主窗体，并使主窗体执行一个方法来响应（这个参数必须用全局变量？）

[xboxeer]

1:利用lambda表达式做闭包
2：在上面闭包的基础上传递一个委托进去 线程返回时回调 或者用Task什么的来做 这个支持异步回调的
[Quote=引用 11 楼 的回复:]

现在网上很多关于 线程间通信 的资料都讲的是：如何子线程来控制UI中的控件。
而我要问的是：1、如何给线程传递一个参数，难道必须用全局变量？
2、如何在线程返回时，传递一个参数给主窗体，并使主窗体执行一个方法来响应（这个参数必须用全局变量？）
[/Quote]

[gao117348222]

用background控件呗

[SocketUpEx]

using System;
using System.Threading;

namespace Test
{
    class Program
    {

        private static void Foo(Object obj)
        {
            if(obj != null)
            {
                ThreadData threadData = obj as ThreadData;
                if (threadData != null)
                {
                        Console.WriteLine(String.Format("ThreadName={0},RunTime={1}", threadData.ThreadName, threadData.RunTime));
                }
            }
        }

        static void Main()
        {
            ThreadData threadData = new ThreadData();
            threadData.ThreadName = "TestThread";
            threadData.RunTime = System.DateTime.Now;

            Thread t = new Thread(new ParameterizedThreadStart(Foo));
            t.IsBackground = true;
            t.Start(threadData);

            Console.ReadKey();
        }
    }

    class ThreadData
    {
        public String ThreadName;
        public DateTime RunTime;
    }
}

[bbjiabcd]

我不想用Control.CheckForIllegalCrossThreadCalls = false;的方法
不想在子线程中控制主窗体的控件。
MessageBox.Show("发送成功", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
MessageBox.Show(ex.Message, "发送邮件出错", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
tSSlblStatus.Text = "";
txtReceive.Enabled = true;
txtTitle.Enabled = true;
txtNeirong.Enabled = true;
btSend.Enabled = true;
btSettings.Enabled = true;
cByxj.Enabled = true;

我希望把这些语句放到主窗体中。
因此必须在子线程运行完成后传送一个参数给主窗体，由主窗体执行这些语句。
怎样才能实现？

[bbjiabcd]

程序现在改成这样，没有问题了，传递参数和回调已经实现。就是传回参数时，用的是全局变量，闭包还是没搞懂。
public class ResultShow
{
public bool Success;
public string ErrMessage;
public ResultShow()
{
Success = false;
ErrMessage = "";
}
public ResultShow(bool suc)
{
Success = suc;
if (suc)
ErrMessage = "";
else
ErrMessage = "Unknown Error";
}
public ResultShow(bool suc, string errm)
{
Success = suc;
if (suc)
ErrMessage = "";
else
ErrMessage = errm;
}
}

public static ResultShow r1 = new ResultShow();
public delegate void MyInvoke();

private void SendEmail(object msg)
{
try
{
client.Send((MailMessage)msg);
r1.Success = true;
}
catch (Exception ex)
{
r1.Success = false;
r1.ErrMessage = ex.Message;
}
MyInvoke mi = new MyInvoke(SendEnd);
this.BeginInvoke(mi);
}

private void SendEnd()
{
if (r1.Success)
{
tSSlblStatus.Text = "发送完成";
MessageBox.Show("发送成功", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
else
{
tSSlblStatus.Text = "发送失败";
MessageBox.Show(r1.ErrMessage, "发送邮件出错", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
}
tSSlblStatus.Text = "";
txtReceive.Enabled = true;
txtTitle.Enabled = true;
txtNeirong.Enabled = true;
btSend.Enabled = true;
btSettings.Enabled = true;
cByxj.Enabled = true;
}

private void btSend_Click(object sender, EventArgs e)
{
tSSlblStatus.Text = "准备发送...";
txtReceive.Enabled = false;
txtTitle.Enabled = false;
txtNeirong.Enabled = false;
btSend.Enabled = false;
btSettings.Enabled = false;
cByxj.Enabled = false;
string mailContent = txtNeirong.Text;

MailMessage msg = new System.Net.Mail.MailMessage();
...
Thread thread = new Thread(new ParameterizedThreadStart(SendEmail));
thread.IsBackground = true;
tSSlblStatus.Text = "正在发送邮件...";
thread.Start(msg);
}

[bbjiabcd]

算了，关于传回参数的问题，在此不深究了。
以上程序已经没有错误，并且能够达到目的了。
谢谢所有回帖的热心朋友！