【WPF】The example of progress bar, label status changed by background worker

来源：互联网发布：淘宝太坑图片编辑：程序博客网时间：2024/06/07 18:28

Demo screenshot;

xaml source code:

<Window x:Class="CommonTesting.MainWindow"        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"        Title="ProcessDisplay" Height="350" Width="525">    <Grid>        <Grid.RowDefinitions>            <RowDefinition Height="*" />            <RowDefinition Height="*" />            <RowDefinition Height="*" />            <RowDefinition Height="*" />            <RowDefinition Height="*" />        </Grid.RowDefinitions>        <Label Grid.Row="0" Name="lblDisplay" />        <ProgressBar Grid.Row="1" Name="pgbPrinting" />        <Button Grid.Row="2" Name="btnPrint" Content="Print" Click="btnPrint_Click" />        <Button Grid.Row="3" Name="btnPause" Content="Pause" IsEnabled="False" Click="btnPause_Click" />        <Button Grid.Row="4" Name="btnCancel" Content="Cancel" IsEnabled="False" Click="btnCancel_Click" />    </Grid></Window>

cs source code:

using System;using System.ComponentModel;using System.Threading;using System.Windows;namespace CommonTesting{    /// <summary>    /// Interaction logic for MainWindow.xaml    /// </summary>    public partial class MainWindow : Window    {        private BackgroundWorker _worker = new BackgroundWorker();        private ManualResetEvent _manualReset = new ManualResetEvent(true);        private bool _isPause = false;        public MainWindow()        {            InitializeComponent();            _worker.DoWork += new DoWorkEventHandler(backgroundWorker_DoWork);            _worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(backgroundWorker_RunWorkerCompleted);            _worker.WorkerSupportsCancellation = true;            //for progress bar            _worker.WorkerReportsProgress = true;            _worker.ProgressChanged += new ProgressChangedEventHandler(backgroundWorker_ProgressChanged);        }        void backgroundWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)        {            pgbPrinting.Value = e.ProgressPercentage;        }        void backgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)        {            if (e.Cancelled)            {                this.Dispatcher.Invoke(new Action(() => {                    lblDisplay.Content = "Cancel...";                    pgbPrinting.Value = 0;                }));            }            else if (e.Error != null)            {                this.Dispatcher.Invoke(new Action(() =>                {                    lblDisplay.Content = "Error...";                    pgbPrinting.Value = 0;                }));            }            else            {                this.Dispatcher.Invoke(new Action(() =>                {                    lblDisplay.Content = "Completed...";                }));            }            btnPrint.IsEnabled = true;        }        void backgroundWorker_DoWork(object sender, DoWorkEventArgs e)        {            this.Dispatcher.Invoke(new Action(() => {                lblDisplay.Content = "Start...";            }));            for (int i = 0; i < 100; i++)            {                Thread.Sleep(100);                if (_worker.CancellationPending)                {                    //receive cancellation message                    e.Cancel = true;                    return;                }                _manualReset.WaitOne();                _worker.ReportProgress(i + 1);            }        }        private void btnPrint_Click(object sender, RoutedEventArgs e)        {            btnPrint.IsEnabled = false;            btnCancel.IsEnabled = btnPause.IsEnabled = true;            _worker.RunWorkerAsync();        }        private void btnCancel_Click(object sender, RoutedEventArgs e)        {            btnPrint.IsEnabled = true;            btnCancel.IsEnabled = btnPause.IsEnabled = false;            if (_isPause)            {                PauseToggle();            }            _worker.CancelAsync();        }        private void btnPause_Click(object sender, RoutedEventArgs e)        {            PauseToggle();        }        private void PauseToggle()        {            _isPause = !_isPause;            if (_isPause)            {                _manualReset.Reset();                btnPause.Content = "Continue";                lblDisplay.Content = "Pause...";            }            else            {                _manualReset.Set();                btnPause.Content = "Pause";                lblDisplay.Content = "Start...";            }        }    }}

0 0