WPF中的多进程(Threading)处理实例(二)
2021-04-13 05:27
标签：www parse ports contains ace tsp percent closed sqrt 说明：public DispatcherOperation BeginInvoke(DispatcherPriority priority, Delegate method);其中DispatcherPriority是从-1到10 的枚举值，10优先级最高。在UpdateTextRight方法中的一下代码段 2.1FindPrimesInput WPF中的多进程(Threading)处理实例(二) 标签：www parse ports contains ace tsp percent closed sqrt 原文地址：https://www.cnblogs.com/lonelyxmas/p/8986724.html
1 //错误的处理
2 private void cmdBreakRules_Click(object sender, RoutedEventArgs e)
3 {
4 Thread thread = new Thread(UpdateTextWrong);
5 thread.Start();
6 }
7
8 private void UpdateTextWrong()
9 {
10 txt.Text = "Here is some new text.";
11 }
12
13 //正确的处理
14 private void cmdFollowRules_Click(object sender, RoutedEventArgs e)
15 {
16 Thread thread = new Thread(UpdateTextRight);
17 thread.Start();
18 }
19
20 private void UpdateTextRight()
21 {
22 this.Dispatcher.BeginInvoke(DispatcherPriority.Normal,
23 (ThreadStart) delegate()
24 {
25 //txt.Text = "Here is some new text.";
26 UpdateText();
27 }
28 );
29 }
30
31 private void UpdateText()
32 {
33
34 txt.Text = "这是更新后的文本。";
35 }
this.Dispatcher.BeginInvoke(DispatcherPriority.Normal,
(ThreadStart)delegate()
{
//txt.Text = "Here is some new text.";
UpdateText();
}
);
可以用一下代码来替换，以增加代码的可读性
private delegate void UpdateTextDelegate();
this.Dispatcher.BeginInvoke(DispatcherPriority.Normal,new UpdateTextDelegate(UpdateText));
其实，这与上篇实例中应用的方法是相同的。
2.BackgroundWorker
FindPrimesInput
1 public class FindPrimesInput
2 {
3 public int To
4 { get; set; }
5
6 public int From
7 { get; set; }
8
9 public FindPrimesInput(int from, int to)
10 {
11 To = to;
12 From = from;
13 }
14
15 }
2.2 Worker
Worker
1 public class Worker
2 {
3 public static int[] FindPrimes(int fromNumber, int toNumber)
4 {
5 return FindPrimes(fromNumber, toNumber, null);
6 }
7
8 public static int[] FindPrimes(int fromNumber, int toNumber, System.ComponentModel.BackgroundWorker backgroundWorker)
9 {
10 int[] list = new int[toNumber - fromNumber];
11
12 // Create an array containing all integers between the two specified numbers.
13 for (int i = 0; i )
14 {
15 list[i] = fromNumber;
16 fromNumber += 1;
17 }
18
19
20 //find out the module for each item in list, divided by each d, where
21 //d is 22 //if the remainder is 0, the nubmer is a composite, and thus
23 //we mark its position with 0 in the marks array,
24 //otherwise the number is a prime, and thus mark it with 1
25
26 //Math.Floor 返回小于或等于指定双精度浮点数的最大整数。
27 int maxDiv = (int)Math.Floor(Math.Sqrt(toNumber));
28
29 int[] mark = new int[list.Length];
30
31 for (int i = 0; i )
32 {
33 for (int j = 2; j )
34 {
35
36 if ((list[i] != j) && (list[i] % j == 0))
37 {
38 mark[i] = 1;
39 }
40
41 }
42
43 int iteration = list.Length / 100;
44 if ((i % iteration == 0) && (backgroundWorker != null))
45 {
46 //BackgroundWorker.CancellationPending获取一个值，指示应用程序是否已请求取消后台操作。
47 if (backgroundWorker.CancellationPending)
48 {
49 // Return without doing any more work.
50 return null;
51 }
52
53 //BackgroundWorker.WorkerReportsProgress 获取或设置一个值，该值指示 System.ComponentModel.BackgroundWorker 能否报告进度更新。
54 if (backgroundWorker.WorkerReportsProgress)
55 {
56 //float progress = ((float)(i + 1)) / list.Length * 100;
57 //BackgroundWorker.ReportProgress 引发 System.ComponentModel.BackgroundWorker.ProgressChanged 事件。
58 backgroundWorker.ReportProgress(i / iteration);
59 //(int)Math.Round(progress));
60 }
61 }
62
63 }
64
65 //create new array that contains only the primes, and return that array
66 int primes = 0;
67 for (int i = 0; i )
68 {
69 if (mark[i] == 0)
70 primes += 1;
71
72 }
73
74 int[] ret = new int[primes];
75 int curs = 0;
76 for (int i = 0; i )
77 {
78 if (mark[i] == 0)
79 {
80 ret[curs] = list[i];
81 curs += 1;
82 }
83 }
84
85 if (backgroundWorker != null && backgroundWorker.WorkerReportsProgress)
86 {
87 backgroundWorker.ReportProgress(100);
88 }
89
90 return ret;
91
92 }
93
94
95 }
2.3BackgroundWorker XAML XAML
1 Window x:Class="Multithreading.BackgroundWorkerTest"
2 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
3 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
4 Title="Multithreading" Height="323.2" Width="305.6"
5 xmlns:cm="clr-namespace:System.ComponentModel;assembly=System"
6 >
7 Window.Resources>
8 cm:BackgroundWorker x:Key="backgroundWorker"
9 WorkerReportsProgress="True" WorkerSupportsCancellation="True"
10 DoWork="backgroundWorker_DoWork" ProgressChanged="backgroundWorker_ProgressChanged"
11 RunWorkerCompleted="backgroundWorker_RunWorkerCompleted">cm:BackgroundWorker>
12 Window.Resources>
13
14 Grid Margin="5">
15 Grid.RowDefinitions>
16 RowDefinition Height="Auto">RowDefinition>
17 RowDefinition Height="Auto">RowDefinition>
18 RowDefinition Height="Auto">RowDefinition>
19 RowDefinition>RowDefinition>
20 RowDefinition Height="Auto">RowDefinition>
21 Grid.RowDefinitions>
22 Grid.ColumnDefinitions>
23 ColumnDefinition Width="Auto">ColumnDefinition>
24 ColumnDefinition>ColumnDefinition>
25 Grid.ColumnDefinitions>
26
27
28 TextBlock Margin="5">From:TextBlock>
29 TextBox Name="txtFrom" Grid.Column="1" Margin="5">1TextBox>
30 TextBlock Grid.Row="1" Margin="5">To:TextBlock>
31 TextBox Name="txtTo" Grid.Row="1" Grid.Column="1" Margin="5">500000TextBox>
32
33 StackPanel Orientation="Horizontal"
34 Grid.Row="2" Grid.Column="1">
35 Button Name="cmdFind"
36 Margin="5" Padding="3"
37 Click="cmdFind_Click">Find PrimesButton>
38 Button Name="cmdCancel"
39 Margin="5" Padding="3" IsEnabled="False"
40 Click="cmdCancel_Click">CancelButton>
41 StackPanel>
42
43 TextBlock Grid.Row="3" Margin="5">Results:TextBlock>
44 ListBox Name="lstPrimes" Grid.Row="3" Grid.Column="1"
45 Margin="5">ListBox>
46
47
48 ProgressBar Name="progressBar"
49 Grid.Row="4" Grid.ColumnSpan="2"
50 Margin="5" VerticalAlignment="Bottom" MinHeight="20"
51 Minimum="0" Maximum="100" Height="20">ProgressBar>
52 Grid>
53 Window>
2.4 CS code 1 public partial class BackgroundWorkerTest : System.Windows.Window
2 {
3 public BackgroundWorkerTest()
4 {
5 InitializeComponent();
6 //BackgroundWorker 在单独的线程上执行操作
7 //Window.FindResource(object resourceKey)搜索具有指定密钥的资源，找不到则会引发异常
8 backgroundWorker = ((BackgroundWorker)this.FindResource("backgroundWorker"));
9 }
10
11 private BackgroundWorker backgroundWorker;
12
13 private void cmdFind_Click(object sender, RoutedEventArgs e)
14 {
15 // Disable the button and clear previous results.
16 cmdFind.IsEnabled = false;
17 cmdCancel.IsEnabled = true;
18 lstPrimes.Items.Clear();
19
20 // Get the search range.
21 int from, to;
22 if (!Int32.TryParse(txtFrom.Text, out from))
23 {
24 MessageBox.Show("Invalid From value.");
25 return;
26 }
27 if (!Int32.TryParse(txtTo.Text, out to))
28 {
29 MessageBox.Show("Invalid To value.");
30 return;
31 }
32
33 // Start the search for primes on another thread.
34 FindPrimesInput input = new FindPrimesInput(from, to);
35 backgroundWorker.RunWorkerAsync(input);
36 }
37
38 private void backgroundWorker_DoWork(object sender, DoWorkEventArgs e)
39 {
40 // Get the input values.
41 FindPrimesInput input = (FindPrimesInput)e.Argument;
42
43 // Start the search for primes and wait.
44 int[] primes = Worker.FindPrimes(input.From, input.To, backgroundWorker);
45
46 //BackgroundWorker.CancellationPending 获取一个值，指示应用程序是否已请求取消后台操作。
47 if (backgroundWorker.CancellationPending)
48 {
49 e.Cancel = true;
50 return;
51 }
52
53 // Return the result.
54 e.Result = primes;
55 }
56
57 private void backgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
58 {
59 if (e.Cancelled)
60 {
61 MessageBox.Show("Search cancelled.");
62 }
63 else if (e.Error != null)
64 {
65 // An error was thrown by the DoWork event handler.
66 MessageBox.Show(e.Error.Message, "An Error Occurred");
67 }
68 else
69 {
70 int[] primes = (int[])e.Result;
71 foreach (int prime in primes)
72 {
73 lstPrimes.Items.Add(prime);
74 }
75 }
76 cmdFind.IsEnabled = true;
77 cmdCancel.IsEnabled = false;
78 progressBar.Value = 0;
79 }
80
81 private void backgroundWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)
82 {
83 //ProgressChangedEventArgs.ProgressPercentage 获取异步任务的进度百分比
84 progressBar.Value = e.ProgressPercentage;
85 }
86
87 private void cmdCancel_Click(object sender, RoutedEventArgs e)
88 {
89 //BackgroundWorker.CancelAsync() 请求取消挂起后的操作
90 backgroundWorker.CancelAsync();
91 }
92 }
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文章标题：WPF中的多进程(Threading)处理实例(二)
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