Question

我的代码是这样的：

private void testToolStripMenuItem_Click(object sender, EventArgs e)
{
    toolStripStatusLabel1.Text = " Device Testing...";

    positive = false;

    clearsensors_gui();
    datarec = false;
    cmd = 04;
    datarec = serialport_FT(0, 1);

    if (datarec)
    {
        char ab = Convert.ToChar(rec_data[1]);
        //MessageBox.Show("\n" + ab + "\n");
        int cab = Convert.ToInt16(ab);
        int cabc1 = cab & 1;
        int cabc2 = cab & 2;
        int cabc3 = cab & 4;
        int cabc4 = cab & 8;
        int cabc5 = cab & 16;
        int cabc6 = cab & 32;

        if (cabc1 == 1)
            ovalShape1.FillColor = Color.Green;
        else
            ovalShape1.FillColor = Color.Red;

        if (cabc2 == 2)
            ovalShape2.FillColor = Color.Green;
        else
            ovalShape2.FillColor = Color.Red;

        if (cabc3 == 4)
            ovalShape3.FillColor = Color.Green;
        else
            ovalShape3.FillColor = Color.Red;

        if (cabc4 == 8)
            ovalShape4.FillColor = Color.Green;
        else
            ovalShape4.FillColor = Color.Red;

        if (cabc5 == 16)
            ovalShape5.FillColor = Color.Green;
        else
            ovalShape5.FillColor = Color.Red;

        if (cabc6 == 32)
            ovalShape6.FillColor = Color.Green;
        else
            ovalShape6.FillColor = Color.Red;

        toolStripStatusLabel1.Text = " Device Tested";
    }
    else
    {
        toolStripStatusLabel1.Text = "Try Again or Communication With Device Failure....";
    }
}

上面的代码是读取传感器，即datarec = serialport_FT（0,1）;函数在GUI端为我提供了一个传感器输出，稍后将用红色\绿色椭圆形描述（1-6）

问题：datarec = serialport_FT(0, 1);此函数需要liltime，因此GUI会冻结，直到那个时候如何避免这种情况？

我尝试使用后台工作程序，但没有把这整个过程放到哪里当进入ovalShape并更改其属性时，也遇到了交叉线程操作错误。

我没有得到在后台使用的函数的哪个部分以及何时何地返回第1个帖子

如果我必须使用线程

，请帮助我使用backgroundworker或使用invoke

Answer 1

你可以这样做：

toolStripStatusLabel1.Text = " Device Testing...";
positive = false;
clearsensors_gui();
datarec = false;
cmd = 04;

BackgroundWorker worker = new BackgroundWorker();

worker.DoWork += delegate(object s, DoWorkEventArgs args)
{
    // Will be run on background thread
    args.Result = serialport_FT(0, 1);
};

worker.RunWorkerCompleted += delegate(object s, RunWorkerCompletedEventArgs args)
{
    bool result = (bool)args.Result;

    if (result)
    {
        // Do your UI updates here
    }
};

worker.RunWorkerAsync();

一项改进可能是将datarec和rec_data组合为args.Result中的元组。

Answer 2

在后台工作程序中，您使用DoWork事件。

worker.DoWork += new DoWorkEventHandler(yourEventHandler); 

void yourEventHandler(object sender, DoWorkEventArgs e)
{
//your work here
}

Answer 3

当您使用WinForms时，这是一篇很棒的MSDN文章，可以帮助您开始在应用程序中使用多个线程：Give Your .NET-based Application a Fast and Responsive UI with Multiple Threads

这篇文章“已有几天了”，但今天的原则仍然绝对有效。

如果您使用的是.NET 4.x版本，还可以使用Task Parallel Library更轻松地处理多个线程。

即将推出的.NET 4.5还提供了更加舒适的等待和asyc关键字：Asynchronous Programming with Async and Await。

Answer 4

将它放在后台线程中，就像你已经尝试过的那样（或者更好的是Task），但要注意只能通过Control.Invoke（对于WinForms）或{{3来调用与GUI相关的操作。（对于WPF）。

Answer 5

使用标签随着任务的进展实时更新。你可以试试这个代码[使用BackGroundWorker]。查看DoWork您放置业务逻辑的位置[请参阅代码中的BusinessClass用法]，然后查看后台任务在任务进行时实时向UI发送信号的ProgressChanged＆amp;最后看到RunWorkerCompleted在任务完成，错误或取消后处理代码的位置。

using System.ComponentModel;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form3 : Form
    {
        private BackgroundWorker _worker;
        BusinessClass _biz = new BusinessClass();
        public Form3()
        {
            InitializeComponent();
            InitWorker();
        }

        private void InitWorker()
        {
            if (_worker != null)
            {
                _worker.Dispose();
            }

            _worker = new BackgroundWorker
            {
                WorkerReportsProgress = true,
                WorkerSupportsCancellation = true
            };
            _worker.DoWork += DoWork;
            _worker.RunWorkerCompleted += RunWorkerCompleted;
            _worker.ProgressChanged += ProgressChanged;
            _worker.RunWorkerAsync();
        }


        void DoWork(object sender, DoWorkEventArgs e)
        {
            int highestPercentageReached = 0;
            if (_worker.CancellationPending)
            {
                e.Cancel = true;
            }
            else
            {
                double i = 0.0d;
                int junk = 0;
                for (i = 0; i <= 199990000; i++)
                {
                    int result = _biz.MyFunction(junk);
                    junk++;

                    // Report progress as a percentage of the total task.
                    var percentComplete = (int)(i / 199990000 * 100);
                    if (percentComplete > highestPercentageReached)
                    {
                        highestPercentageReached = percentComplete;
                        // note I can pass the business class result also and display the same in the LABEL  
                        _worker.ReportProgress(percentComplete, result);
                        _worker.CancelAsync();
                    }
                }

            }
        }

        void RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            if (e.Cancelled)
            {
                // Display some message to the user that task has been
                // cancelled
            }
            else if (e.Error != null)
            {
                // Do something with the error
            }
        }

        void ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            label1.Text =  string.Format("Result {0}: Percent {1}",e.UserState, e.ProgressPercentage);
        }
    }

    public class BusinessClass
    {
        public int MyFunction(int input)
        {
            return input+10;
        }
    }
}

如何避免冻结GUI？

5 个答案: