Wpf Backgroundworker

1. <Window x:Class="WpfApp53.MainWindow"
2. xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
3. xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
4. xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
5. xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
6. xmlns:local="clr-namespace:WpfApp53"
7. mc:Ignorable="d"
8. Title="MainWindow" Height="450" Width="800">
9. <Grid>
10. <Grid.RowDefinitions>
11. <RowDefinition Height="*"/>
12. <RowDefinition Height="Auto"/>
13. <RowDefinition Height="Auto"/>
14. <RowDefinition Height="Auto"/>
15. </Grid.RowDefinitions>
16. <ListBox Grid.Row="0" x:Name="listBox1"/>
17. <ProgressBar Grid.Row="1" x:Name="progressBar1" Height="20" Margin="5"/>
18. <StackPanel Grid.Row="2" Orientation="Horizontal" Margin="5">
19. <TextBlock Text="Status: "/>
20. <TextBlock x:Name="statusTextBox"/>
21. </StackPanel>
22. <Grid Grid.Row="3" Margin="10">
23. <Grid.ColumnDefinitions>
24. <ColumnDefinition Width="*"/>
25. <ColumnDefinition Width="*"/>
26. </Grid.ColumnDefinitions>
27. <Button Grid.Column="0" x:Name="startBtn" Content="Start" Click="StartBtn_Click"/>
28. <Button Grid.Column="1" x:Name="cancelBtn" Content="Cancel" Click="CancelBtn_Click"/>
29. </Grid>
30. </Grid>
31. </Window>

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1. 1 using System;
2. 2 using System.Collections.Generic;
3. 3 using System.ComponentModel;
4. 4 using System.Linq;
5. 5 using System.Text;
6. 6 using System.Threading;
7. 7 using System.Threading.Tasks;
8. 8 using System.Windows;
9. 9 using System.Windows.Controls;
10. 10 using System.Windows.Data;
11. 11 using System.Windows.Documents;
12. 12 using System.Windows.Input;
13. 13 using System.Windows.Media;
14. 14 using System.Windows.Media.Imaging;
15. 15 using System.Windows.Navigation;
16. 16 using System.Windows.Shapes;
17. 17
18. 18 namespace WpfApp53
19. 19 {
20. 20 /// <summary>
21. 21 /// Interaction logic for MainWindow.xaml
22. 22 /// </summary>
23. 23 public partial class MainWindow : Window
24. 24 {
25. 25 BackgroundWorker bgWorker;
26. 26 public MainWindow()
27. 27 {
28. 28 InitializeComponent();
29. 29 cancelBtn.IsEnabled = false;
30. 30 }
31. 31
32. 32 private void StartBtn_Click(object sender, RoutedEventArgs e)
33. 33 {
34. 34 listBox1.Items.Clear();
35. 35 startBtn.IsEnabled = false;
36. 36 cancelBtn.IsEnabled = true;
37. 37 bgWorker = new BackgroundWorker();
38. 38 bgWorker.DoWork += BgWorker_DoWork;
39. 39 bgWorker.ProgressChanged += BgWorker_ProgressChanged;
40. 40 bgWorker.RunWorkerCompleted += BgWorker_RunWorkerCompleted;
41. 41 bgWorker.WorkerReportsProgress = true;
42. 42 bgWorker.WorkerSupportsCancellation = true;
43. 43
44. 44 int maxItems = 50;
45. 45 progressBar1.Minimum = 1;
46. 46 progressBar1.Maximum = 100;
47. 47
48. 48 statusTextBox.Text = "Starting...";
49. 49 bgWorker.RunWorkerAsync(maxItems);
50. 50 }
51. 51
52. 52 private void BgWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
53. 53 {
54. 54 if(e.Cancelled)
55. 55 {
56. 56 statusTextBox.Text = "Cancelled";
57. 57 }
58. 58 else
59. 59 {
60. 60 statusTextBox.Text = "Completed";
61. 61 }
62. 62 statusTextBox.IsEnabled = true;
63. 63 cancelBtn.IsEnabled = false;
64. 64 }
65. 65
66. 66 private void BgWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)
67. 67 {
68. 68 double percent = (e.ProgressPercentage * 100) / 50;
69. 69 progressBar1.Value = Math.Round(percent, 0);
70. 70 listBox1.Items.Add(new ListBoxItem { Content = e.ProgressPercentage + " item added" });
71. 71 statusTextBox.Text = Math.Round(percent, 0) + "% percent completed";
72. 72 }
73. 73
74. 74 private void BgWorker_DoWork(object sender, DoWorkEventArgs e)
75. 75 {
76. 76 int? maxItems = e.Argument as int?;
77. 77 for(int i=1;i<=maxItems.GetValueOrDefault();i++)
78. 78 {
79. 79 if(bgWorker.CancellationPending)
80. 80 {
81. 81 e.Cancel = true;
82. 82 break;
83. 83 }
84. 84 Thread.Sleep(200);
85. 85 bgWorker.ReportProgress(i);
86. 86 }
87. 87 }
88. 88
89. 89 private void CancelBtn_Click(object sender, RoutedEventArgs e)
90. 90 {
91. 91 bgWorker.CancelAsync();
92. 92 startBtn.IsEnabled = true;
93. 93 }
94. 94 }
95. 95 }

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来源：https://www.cnblogs.com/Fred1987/archive/2019/09/15/11523444.html