WPF 精修篇 长时间线程加取消功能

原文:WPF 精修篇 长时间线程加取消功能

    <Grid>





        <Grid.RowDefinitions>





            <RowDefinition Height="11*"/>





            <RowDefinition Height="29*"/>





        </Grid.RowDefinitions>





        <StackPanel Orientation="Horizontal" Margin="0" VerticalAlignment="Center">





            <Label>开始数据</Label>





            <TextBox x:Name="beginText" HorizontalAlignment="Left" Height="31" TextWrapping="Wrap" Text="100" VerticalAlignment="Top" Width="100"/>





            <Label>结束数据</Label>





            <TextBox x:Name="endText" HorizontalAlignment="Left" Height="31" TextWrapping="Wrap" Text="1000000000" VerticalAlignment="Top" Width="100"/>





            <Button x:Name="button" Content="开始" HorizontalAlignment="Center" VerticalAlignment="Center" Width="75" Click="Button_Click"/>





            <Button x:Name="Cancel" Content="取消" HorizontalAlignment="Center" VerticalAlignment="Center" Width="75" Click="Cancel_Click"/>





        </StackPanel>





        <StackPanel Margin="0" Grid.Row="1">





            <TextBlock x:Name="odd" TextWrapping="Wrap"  Text="奇数数量："/>





            <TextBlock x:Name="even" TextWrapping="Wrap" Text="偶数数量："/>





        </StackPanel>





    </Grid>

        private int oddcount =0;





        private int evencount =0;





        public void Make(int from ,int to) 





        {





            for (int i = from; i < to; i++)





            {





                if (TokenSource.IsCancellationRequested) 





                {





                    evencount = -1;





                    oddcount = -1;





                    return;





                }





                if (i % 2 == 0)





                {





                    evencount++;





                }





                else 





                {





                    oddcount++;





                }





            }





        }





        private void Button_Click(object sender, RoutedEventArgs e)





        {





            int from=0;





            int to = 0;





            if(int.TryParse(beginText.Text,out from)&&int.TryParse(endText.Text,out to) )





            {





                button.IsEnabled = false;





                ThreadPool.QueueUserWorkItem(_ =>





                {





                    TokenSource = new CancellationTokenSource();





                    Make(from, to);





                   





                    Dispatcher.BeginInvoke(new Action(() =>





                    {





                        if (oddcount < 0 || evencount < 0)





                        {





                            odd.Text = "操作取消";





                            even.Text = "操作取消";





                        }





                        else





                        {





                            odd.Text = "奇数数量：" + oddcount;





                            even.Text = "偶数数量：" + evencount;





                        }





                        button.IsEnabled = true;





                    }));





                  





                });





        





            }





 





        }





 





        public CancellationTokenSource TokenSource = null;





        private void Cancel_Click(object sender, RoutedEventArgs e)





        {





            if (TokenSource != null) 





            {





                TokenSource.Cancel();





                TokenSource = null;





            }





 





        }