Threads Dispatchers Static Code

public partial class TestWindow : Window
{
public ICommand ExecuteAction;
public MainWindow()
{
InitializeComponent();
}
Thread th;
Thread thMain;
private void BtnTest_Click(object sender, RoutedEventArgs e)
{
th = new Thread(UpdateValue);
th.Start();
}
private void BtnSearch_Click(object sender, RoutedEventArgs e)
{
string sourceDir = string.Empty;
string searchText = string.Empty;
wpMain.Children.Clear();
sourceDir = txtInputDir.Text.Trim();
searchText = txtInput.Text.Trim();
thMain = new Thread(() => PerformAction(sourceDir, searchText));
thMain.SetApartmentState(ApartmentState.MTA);
thMain.Start();
}
private void PerformAction(string sourceDir, string searchText)
{
try
{
//sourceDir = @"C:\Users\santhosh.polu\source\repos\TFS_JIRA_SUPPORT_Solution";
if (Directory.Exists(sourceDir))
{
List<string> lstDirsFiles = Directory.GetDirectories(sourceDir, "*", SearchOption.AllDirectories).ToList();
List<string> lstDirsFiles1 = Directory.GetFiles(sourceDir, "*", SearchOption.AllDirectories).ToList();
lstDirsFiles.AddRange(lstDirsFiles1);
int totalCount = lstDirsFiles.Count;
if (totalCount < 1)
return;
if (lstDirsFiles.Count > 0)
{
int i = 0;
while (i < lstDirsFiles.Count)
{
string currentItem = lstDirsFiles[i];
Dispatcher.Invoke(new Action(() =>
{
lblStatus.Content = currentItem;
}));
if (Directory.Exists(currentItem))
{
DirectoryInfo dir = new DirectoryInfo(currentItem);
String dirName = dir.Name.ToString();
if (dirName.ToLower().Contains(searchText.ToLower()))
{
Dispatcher.Invoke(new Action(() =>
{
Button btn = new Button();
btn.Content = dirName;
btn.Background = Brushes.AliceBlue;
btn.ToolTip = "Directory : " + dir.FullName;
btn.Tag = dir.FullName;
btn.Click += Btn_Click;
wpMain.Children.Add(btn);
}));
}
}
else if (File.Exists(currentItem))
{
FileInfo fi = new FileInfo(currentItem);
String fileName = fi.Name.ToString();
if (fileName.ToLower().Contains(searchText.ToLower()))
{
Dispatcher.Invoke(new Action(() =>
{
Button btn = new Button();
btn.Content = fileName;
btn.ToolTip = "File : " + System.IO.Path.GetDirectoryName(fileName);
btn.Background = Brushes.IndianRed;
btn.Tag = System.IO.Path.GetDirectoryName(fileName);
btn.Click += Btn_Click1;
wpMain.Children.Add(btn);
}));
}
}
i++;
}
}
else
{
MessageBox.Show("No Directories exist.");
}
}
else
{
MessageBox.Show("Directory Does not exist.");
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message.ToString() + System.Environment.NewLine + ex.StackTrace.ToString());
}
}
private void Btn_Click1(object sender, RoutedEventArgs e)
{
Button btn = sender as Button;
Process.Start("explorer.exe", btn.Tag.ToString());
}
private void Btn_Click(object sender, RoutedEventArgs e)
{
Button btn = sender as Button;
Process.Start("explorer.exe", btn.Tag.ToString());
}
public void UpdateValue()
{
while (true)
{
Application.Current.Dispatcher.Invoke(
DispatcherPriority.Background,
new Action(() =>
{
txtCurrent.Text = DateTime.Now.ToString("DD MM yyyy hh mm ss");
}));
}
}
private void BtnStop_Click(object sender, RoutedEventArgs e)
{
if (thMain!= null)
{
thMain.Abort();
}
}
}

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

Santhosh7y ago
I got the solution. It is Just Context Switching.

Every time we Use Dispatcher, UI thread is accessed and then control goes to main thread.
In my code, same thing happend.

In While loop i am using Dispatcher which is causing the problem.

Amit Gupta
Dispatcher is asynchronous i guess.

Thanks for Giving me a new idea.
Amit Gupta7y ago
Do take advantage of async await feature to traverse the directory asynchronously. Please beaware that using Diapatcher.Invoke is synchronous and runs on main thread which leads to UI freezing.

Threads Dispatchers Static Code

Amit Gupta