进度条工作但标签未更新

Question

我有一个带接口的库.

Public Interface Progress
{
    int ProgressValue{get;set;},
    string ProgressText{get;set;},
}

库有一个方法Create(虚拟代码):

Public Class TestLibrary
{

    Progress _progress;

    Public void Create()
    {
        foreach(var n in TestList)
        {
            // Do Something
            _progress.ProgressValue = GetIndex(n);
            _progress.ProgressText = "Updating..." + n;
        }
    }
}

我有一个引用此库并调用Create方法的项目.它甚至实现了接口进度.

Public Class TestProject : Progress
{
    public int ProgressValue
    {
        get{return progressBar1.Value;}
        set{progressBar1.Value = value;}
    }

    public int ProgressText
    {
        get{return label1.Text;}
        set{label1.Text = value;}
    }
}

现在,当我运行应用程序时,Progress Bar表现正常并正确显示进度,但label1的Text文本根本没有变化.但它在for循环结束时会发生变化并显示循环中的最后一项.任何人都可以帮助我吗？

注意:所有这些代码都是直接编写的,没有经过测试,因为我现在没有我的应用程序.对不起任何语法错误.

Answer 1

听起来你的所有工作都是在UI线程上完成的.不要那样做.

相反,在后台线程中运行循环本身,并使用Control.Invoke或Control.BeginInvoke(可能在Progress实现中)将调用编组到UI线程以更新UI.这将使您的UI在处理时保持响应(并且能够更新标签等).

Answer 2

用过的Label instead of ProgressBar.你可以尝试这段代码[ using BackGroundWorker] -

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;
        }
    }
}

几天前发布在这里