如何使用ProgressBar更新正确实现BackgroundWorker？
也问了这个问题
为了对发生的事情有一个清晰的了解，并考虑到评论，本文的内容也来自这里
我现在真正想做的是调用一个带有进度条的新表单，并使其运行并进行动画处理，同时我的后台线程将我的长进程运行到数据库中，然后调用关闭表单事件
后台工作者在这里设置
public partial class MainWindow : Window{
//Declare background workers
BackgroundWorker bw = new BackgroundWorker();
BackgroundWorker bwLoadCSV = new BackgroundWorker();
BackgroundWorker bwProgressBar = new BackgroundWorker();
然后代表们在这里添加
public MainWindow() {
bwLoadCSV.WorkerReportsProgress = true;
bwLoadCSV.WorkerSupportsCancellation = true;
bwLoadCSV.DoWork += new DoWorkEventHandler(bwLoadCSV_DoWork);
bwLoadCSV.ProgressChanged += new ProgressChangedEventHandler(bwLoadCSV_ProgressChanged);
bwLoadCSV.RunWorkerCompleted += new RunWorkerCompletedEventHandler(bwLoadCSV_RunWorkerCompleted);
调用是从主窗口类在这里进行的
private void CSV_Load_Click(object sender, RoutedEventArgs e) ///Function to read csv into datagrid
///
{
//Turn Cursor to wait
System.Windows.Forms.Cursor.Current = System.Windows.Forms.Cursors.WaitCursor;
//Test connection to sql server
if (CHHoursDataProvider.IsDatabaseOnline() == false)
{
System.Windows.Forms.MessageBox.Show("Can not establish contact with sql server" + "\n" + "Contact IT", "Connection Error");
//Set UI picture
return;
}
//Set a control to update the user here
tbLoadDgStat.Visibility = Visibility.Visible;
tbLoadDgStat.Text = "Getting data templete from Database...";
string FilePath = txFilePath.Text;
if (bwLoadCSV.IsBusy != true)
{
//load the context object with parameters for Background worker
bwCSVLoadContext Context = new bwCSVLoadContext();
Context.Site = cBChSite.Text;
Context.FilePath = txFilePath.Text;
Context.FileName = fileTest;
Context.Wageyear = cbWageYear.Text;
Context.Startdate = ((DateTime)dpStartDate.SelectedDate);
Context.Enddate = ((DateTime)dpEndDate.SelectedDate);
bwLoadCSV.RunWorkerAsync(Context);
}
后台工作者做的工作是
private void bwLoadCSV_DoWork(object sender, DoWorkEventArgs e) {
BackgroundWorker worker = sender as BackgroundWorker;
bwCSVLoadContext Context = e.Argument as bwCSVLoadContext;
worker.ReportProgress((10));
if ((worker.CancellationPending == true))
{
e.Cancel = true;
}
else
{
// Perform a time consuming operation and report progress load csv into datagrid.
为了报告后台工作，我这样做。在这里，我试图加载一个新的名为ProgressDialog的表单，该表单上有一个进度条，我尝试将其设置为Indeterminable，这样它就可以在我的ProgressDialoge表单中“摆动”，以向用户显示正在进行的操作。我已经使用了后台工作中的报告程序部分，因为我相信它可以访问主窗口线程，并且我希望从主窗口线程中调用invoke方法，但是我不确定
这是记者
private void bwLoadCSV_ProgressChanged(object sender, ProgressChangedEventArgs e) {
this.Dispatcher.Invoke((MethodInvoker)delegate { tbLoadDgStat.Visibility = Visibility.Visible; });
//tbLoadDgStat.Visibility = Visibility.Visible;
//this.progressBar1.Value = e.ProgressPercentage;//This works but pauses on long steps
if (e.ProgressPercentage == 10)
{
//Try to open a new form with a class ProgressDialog and set the progressbar
// on the frm to IsIndeterminate=true
//THIS IS NOT WORKING
this.Dispatcher.BeginInvoke (new Action(() =>
{ ProgressDialog progressDialog = new ProgressDialog();
progressDialog.SetIndeterminate(true);
}));
//this updates the main form OK
this.Dispatcher.Invoke((MethodInvoker)delegate { tbLoadDgStat.Text = "Getting data templete from Database..."; });
}
else if (e.ProgressPercentage == 20)
{
this.Dispatcher.Invoke((MethodInvoker)delegate { tbLoadDgStat.Text = "Data template retrieved..."; });
}
else
{
if (e.ProgressPercentage % 10 == 0)
{
this.Dispatcher.Invoke((MethodInvoker)delegate { tbLoadDgStat.Text = "Adding Data..." + e.ProgressPercentage.ToString() + "%"; });
}
}
最后是ProgressDialog表单的xaml及其类
<Window x:Class="Test_Read_CSV.ProgressDialog" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Progress Dialog" Height="115" Width="306" Name="ProgressPopup">
<Grid>
<ProgressBar Height="31" HorizontalAlignment="Left" Margin="12,33,0,0" Name="progressBar1" VerticalAlignment="Top" Width="250" />
<TextBox Height="23" HorizontalAlignment="Left" Margin="7,4,0,0" Name="tbEvent" VerticalAlignment="Top" Width="254" IsReadOnly="True" IsEnabled="False" />
</Grid>
类
/// <summary>/// Interaction logic for ProgressDialog.xaml
/// </summary>
public partial class ProgressDialog : Window
{
public ProgressDialog()
{
WindowStartupLocation = WindowStartupLocation.CenterScreen;
InitializeComponent();
}
public ProgressDialog(String Purpose)
{
InitializeComponent();
tbEvent.Text = Purpose;
WindowStartupLocation = WindowStartupLocation.CenterScreen;
}
public void UpdateProgress(int progress)
{
progressBar1.Dispatcher.BeginInvoke(
new Action(() =>
{
progressBar1.Value = progress;
}
));
}
public void SetIndeterminate(bool isIndeterminate)
{
progressBar1.Dispatcher.BeginInvoke(
new Action(() =>
{
if (isIndeterminate)
{
progressBar1.IsIndeterminate = true;
}
else
{
progressBar1.IsIndeterminate = false;
}
}
));
}
}
}
我已经阅读并完成了一些有关后台工作者的教程，甚至还涉及了一些线程，但似乎无法获得我想要的结果
我的想法是，我有两个漫长的过程，我要么从远程bd获取数据表克隆，要么从wpf应用程序（.net
4）更新数据库。在进程运行时，我希望有一个进度条控件并对其进行更新，原因很明显，这是为了明确一些工作正在进行。因此，我在后台工作程序中执行了常规的报告进度例程，并且可以正常工作…但是，在我的dowork线程中，我有以下命令
CHHoursDataProvider CH = new CHHoursDataProvider();oTable = CH.CloneCHHours();
这是与db进行通信的地方，并且该命令在vpn远程连接上花费了60-90秒，因此即使我这样做
CHHoursDataProvider CH = new CHHoursDataProvider();worker.ReportProgress((10));
oTable = CH.CloneCHHours();
worker.ReportProgress((20));
主窗口看起来仍然冻结，好像已经崩溃了！
因此，我要做的就是在调用后台工作的开始时将进度条设置为运行，并使其保持运行状态直到任务结束。这是完成我的第一个项目所需要做的，三天后，我仍然无法解决这个问题！
所以我尝试了以下
在bw中，进度已更改，并且在主窗口类中
this.progressBar2.IsIndeterminate = true;但是，动画直到Dowork线程完成才开始。
然后，我创建了另一个后台工作程序来更新progressbar2，该程序链接到主窗口上的按钮是可以的，但是当我尝试从另一个后台工作程序或主窗口类中使用它时，直到工作完成后，线程已在第一个后台工作者上完成
然后，我尝试遵循一个invoke方法，但真的迷失了！
所以任何人都可以帮忙，我可以猜测这与线程和在错误的线程上工作等有关，但是我对此一无所知。
我可以根据需要发布更多代码
伊恩
回答：
由于您没有显示完整的BackgroundWorker代码，所以我无法确定您是否正确实现了它。这样，我所能做的就是向您展示一个更新ProgressBar控件的简单工作示例：
UserControl XAML：
<UserControl x:Class="WpfApplication1.Views.TestView" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300" Loaded="UserControl_Loaded">
<ProgressBar x:Name="progressBar" Height="25" Margin="20" Minimum="0"
Maximum="50" />
</UserControl>
MainWindow XAML：
<Window x:Class="WpfApplication1.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:Views="clr-namespace:WpfApplication1.Views"
Title="MainWindow" Height="350" Width="525">
<Views:TestView />
</Window>
UserControl 后面的代码：
using System.ComponentModel;using System.Threading;
using System.Windows;
using System.Windows.Controls;
namespace WpfApplication1.Views
{
public partial class TestView : UserControl
{
private BackgroundWorker backgroundWorker = new BackgroundWorker();
public TestView()
{
InitializeComponent();
backgroundWorker.WorkerReportsProgress = true;
backgroundWorker.ProgressChanged += ProgressChanged;
backgroundWorker.DoWork += DoWork;
// not required for this question, but is a helpful event to handle
backgroundWorker.RunWorkerCompleted += BackgroundWorker_RunWorkerCompleted;
}
private void UserControl_Loaded(object sender, RoutedEventArgs e)
{
backgroundWorker.RunWorkerAsync();
}
private void DoWork(object sender, DoWorkEventArgs e)
{
for (int i = 0; i <= 100; i++)
{
// Simulate long running work
Thread.Sleep(100);
backgroundWorker.ReportProgress(i);
}
}
private void ProgressChanged(object sender, ProgressChangedEventArgs e)
{
// This is called on the UI thread when ReportProgress method is called
progressBar.Value = e.ProgressPercentage;
}
private void BackgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
// This is called on the UI thread when the DoWork method completes
// so it's a good place to hide busy indicators, or put clean up code
}
}
}
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