Develop Reference

Showing busy indicator on a STA thread

I have a long operation wehre I'd like to show the Extended Toolkits busy indicator. I made a previous post about this and it was fixed Wpf Extended toolkit BusyIndicator not showing during operation. However, during that call I have to interact with a UI element (canvas) and I get a "The calling thread must be STA, because many UI components require this". I understand (now) that a background worker(see code):
private void CboItemId_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
BackgroundWorker _backgroundWorker = new BackgroundWorker();
_backgroundWorker.DoWork += new DoWorkEventHandler(backgroundWorker_DoWork);
_backgroundWorker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(_backgroundWorker_RunWorkerCompleted);
ItemSearchBusyIndicator.IsBusy = true;
// Mouse.OverrideCursor = System.Windows.Input.Cursors.Wait;
if (RdoItemSearch.IsChecked == false) return;
///backgroundWorker_DoWork(null, null);
if (CboItemId.SelectedValue == null) return;
if (CboItemId.SelectedValue.ToString() != string.Empty)
{
selectedItem = CboItemId.SelectedValue.ToString();
_backgroundWorker.RunWorkerAsync();
}
// Mouse.OverrideCursor = System.Windows.Input.Cursors.Arrow;
}
public void backgroundWorker_DoWork(object sender, DoWorkEventArgs e)
{
LoadItemData(selectedItem);
}
uses MTA and cannot be set to STA. So i tried calling the internal function that uses the UI elelment in its own thread:
public void LoadItemData(string itemId)
{
Axapta ax = new Axapta();
files.Clear();
try
{
ax.Logon(Settings.Default.Server, null, Settings.Default.Test, null);
AxaptaContainer path = (AxaptaContainer)ax.CallStaticClassMethod(Settings.Default.ClassName, Settings.Default.ItemData, itemId);
for (int i = 1; i <= path.Count; i++)
{
AxaptaContainer somestring = (AxaptaContainer)path.get_Item(i);
for (int j = 1; j <= somestring.Count; j += 2)
{
string extension = Path.GetExtension(somestring.get_Item(j + 1).ToString().ToLower());
if (extension == ".jpg"
|| extension == ".jpeg"
|| extension == ".gif"
|| extension == ".png"
|| extension == ".bmp"
|| extension == ".pdf")
/* key=path - value=description */
files.Add(somestring.get_Item(j + 1).ToString(), somestring.get_Item(j).ToString());
}
}
// _canvas.Children.Clear();
Thread t = new Thread(new ThreadStart(LoadPictures));
t.SetApartmentState(ApartmentState.STA);
t.Start();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
ax.Logoff();
}
}
Heres where I interact with the canvas element:
private void LoadPictures()
{
foreach (DictionaryEntry filePath in files)
{
try
{
Picture p = new Picture();
ToolTip t = new ToolTip();
t.Content = filePath.Value;
p.ToolTip = t;
TextBlock tb = new TextBlock();
tb.Text = filePath.Value.ToString();
Canvas.SetTop(tb, y);
Canvas.SetLeft(tb, x);
p.ImagePath = filePath.Key.ToString();
p.OriginalImagePath = filePath.Key.ToString();
p.ImageName = filePath.Value.ToString();
_canvas.Children.Add(p); //<-------This is where i seem to error
}
catch (Exception ex)
{
MessageBox.Show("Error:" + ex.Message,"File Load Error",MessageBoxButton.OK,MessageBoxImage.Error);
}
}
}
but I get a "The calling thread cannot access this object because a different thread owns it"
I don't know how to call the long running (LoadItemData()) function while showing the BusyIndicator without a backgroundworker. Any help appreciated

There are multiple approaches:
1) Async binding, it's not recommended, but it is there. You can run long running task in property getter, framework will prevent UI from blocking, when it is finished - UI will get updated.
2) Use BackgroundWorker or Task/Thread to run code, but invoke it into UI thread. In your example:
Dispatcher.InvokeAsync(() => _canvas.Children.Add(p));
3) You can block UI thread of main window completely, no problems. But to indicate about its being busy you can create window in another thread and show there busy status (run animations, etc):
var thread = new Thread(() =>
{
var window = new SomeWindow();
window.ShowDialog();
});
thread.SetApartmentState(ApartmentState.STA);
thread.IsBackground = true;
thread.Start();

Increment ProgressBar within another class

it's my first question I'm asking here, so please be gentle with me ;)
So I've actually got two WinForms in my C# application I'm writing at the moment (I'm quite new to C#).
This window has a button, which saves photos from an usb device you selected before in a list box to another folder.
After clicking on this button my main thread is of course busy with copying, so I decided to create another WinForm which contains my ProgressBar.
Foreach completed copy, I want to increment my ProgressBar accordingly.
So I count the number of copies I have to do and give it the progressbar as maximum. But my problem at the moment is, that I really don't know how to increment the ProgressBar without getting a Thread Unsafe Exception.
Here's my ProgressWindow code:
public partial class ProgressWindow : Form
{
BackgroundWorker updateProgressBarThread = new BackgroundWorker();
private Boolean _isThreadRunning = false;
public Boolean IsThreadRunning
{
get { return _isThreadRunning; }
set { _isThreadRunning = value; }
}
private int _progressbarLength;
public int ProgressbarLength
{
get { return _progressbarLength; }
set { _progressbarLength = value; }
}
private int progress = 1;
public ProgressWindow()
{
Show();
InitializeComponent();
}
private void StartUpdateThread(object sender, DoWorkEventArgs e)
{
BackgroundWorker worker = sender as BackgroundWorker;
// Reports progress to the ProgressChangedEvent function. (Thread Safe)
}
private void FinishProgressThread(object sender, RunWorkerCompletedEventArgs e)
{
if (!_isThreadRunning)
{
MessageBox.Show("Erfolgreich kopiert");
Close();
}
}
private void ProgressChangedEvent(object sender, ProgressChangedEventArgs e)
{
this.copyProgressbar.Value = e.ProgressPercentage;
this.progressStatus.Text = e.ProgressPercentage.ToString();
}
public void CallUpdateThread()
{
updateProgressBarThread.WorkerReportsProgress = true;
updateProgressBarThread.DoWork += new DoWorkEventHandler(StartUpdateThread);
updateProgressBarThread.ProgressChanged += new ProgressChangedEventHandler(ProgressChangedEvent);
updateProgressBarThread.RunWorkerCompleted += new RunWorkerCompletedEventHandler(FinishProgressThread);
updateProgressBarThread.RunWorkerAsync();
}
}
I want to increment my ProgressBar with 1 after each succesful copy.
How do I do this from my main thread?
This is the function which actually handles the copy process
private void SaveFile(System.IO.DirectoryInfo root)
{
try
{
IEnumerable<DirectoryInfo> directoriesNames = root.EnumerateDirectories();
// New instance of thread ProgressWindow.
ProgressWindow progress = new ProgressWindow();
progress.CallUpdateThread();
foreach (DirectoryInfo element in directoriesNames)
{
// Query all subdirectories and count everything with the in the configuration made settings.
if (!element.Attributes.ToString().Contains("System"))
{
// Now we insert the configuration we applied.
String fileExtension = null;
if (Properties.Settings.Default._configPhoto)
{
fileExtension = "*.jpg";
}
if (Properties.Settings.Default._configWordDocument)
{
fileExtension = "*.odt";
}
FileInfo[] jpgList = element.GetFiles(fileExtension, SearchOption.AllDirectories);
// set the size of the progress bar
progress.ProgressbarLength = jpgList.Count();
// Now we go through all our results and save them to our backup folder.
foreach (FileInfo tmp in jpgList)
{
string sourceFilePath = tmp.FullName;
string destFilePath = PATHTOBACKUP + "\\" + tmp.Name;
progress.IsThreadRunning = true;
try
{
System.IO.File.Copy(sourceFilePath, destFilePath, true);
}
catch (IOException ioe)
{
MessageBox.Show(ioe.Message);
}
}
}
}
// progress.IsThreadRunning = false;
}
catch (UnauthorizedAccessException e)
{
MessageBox.Show(e.Message);
}
}
It's pretty obvious that I have to do this after this function
System.IO.File.Copy(sourceFilePath, destFilePath, true);
But how do I report this to my ProgressWindow?
I really hope I explained it well enough, not sure if I'm missing something important.
Thanks in advance guys

Here is a compact example of the key components:
Clicking button starts new thread worker
Progress is done by file lengths, not by number of files
BeginInvoke used to update the progress bar (avoid cross Thread exception)
ProgressBar pb = new ProgressBar() { Minimum = 0, Maximum = 100 };
Button btn = new Button();
btn.Click += delegate {
Thread t = new Thread(() => {
DirectoryInfo dir = new DirectoryInfo("C:\\temp\\");
var files = dir.GetFiles("*.txt");
long totalLength = files.Sum(f => f.Length);
long length = 0;
foreach (var f in files) {
length += f.Length;
int percent = (int) Math.Round(100.0 * length / totalLength);
pb.BeginInvoke((Action) delegate {
pb.Value = percent;
});
File.Copy(f.FullName, "...");
}
});
t.IsBackground = true;
t.Start();
};

Want to use Task Parallel Library with progress reporting for updating database

i developed a application where multiple connection string are stored. i just iterate in for loop and connect each db and execute sql against each db. in this way i update multiple database with bulk sql statement.
Now i need to use now Task Parallel Library to update multiple db simultaneously instead of updating one after one in loop. i also want to handle exception and also want to show multiple progress bar for multiple database operation. pause & resume functionality should be there.
when i will click on button then multiple db connection will be open and for each task a new progress bar will be added in my form. each progress bar will show each db operation progress. when any task will be finish then that corresponding progress bar will be removed from form.
any one can guide me with sample code how to do it using TPL.
here i got one code which update one progressbar but i need to update multiple progress bar.
int iterations = 100;
ProgressBar pb = new ProgressBar();
pb.Maximum = iterations;
pb.Dock = DockStyle.Fill;
Controls.Add(pb);
Task.Create(delegate
{
Parallel.For(0, iterations, i =>
{
Thread.SpinWait(50000000); // do work here
BeginInvoke((Action)delegate { pb.Value++; });
});
});
UPDATE Question
i did it in this way. code works but all progress bar value increase sequentially.
i have one form and one user control in winform apps. please have a look at my code and tell me what is wrong there.
main for code
public partial class Main : Form
{
public Main()
{
InitializeComponent();
this.DoubleBuffered = true;
}
private void btnStart_Click(object sender, EventArgs e)
{
Progress ucProgress = null;
Dictionary<string, string> dicList = new Dictionary<string, string>();
dicList.Add("GB", "conn1");
dicList.Add("US", "conn2");
dicList.Add("DE", "conn3");
fpPanel.Controls.Clear();
Task.Factory.StartNew(() =>
{
foreach (KeyValuePair<string, string> entry in dicList)
{
ucProgress = new Progress();
ucProgress.Country = entry.Key;
ucProgress.DBConnection = entry.Value;
fpPanel.BeginInvoke((MethodInvoker)delegate
{
fpPanel.Controls.Add(ucProgress);
ucProgress.Process();
});
//fpPanel.Controls.Add(ucProgress);
System.Threading.Thread.SpinWait(5000000);
}
});
}
private void Main_Resize(object sender, EventArgs e)
{
this.Invalidate();
}
private void Main_Paint(object sender, PaintEventArgs e)
{
using (LinearGradientBrush brush = new LinearGradientBrush(this.ClientRectangle,
Color.WhiteSmoke,
Color.LightGray,
90F))
{
e.Graphics.FillRectangle(brush, this.ClientRectangle);
}
}
}
user control code
public partial class Progress : UserControl
{
public Progress()
{
InitializeComponent();
lblMsg.Text = "";
pbStatus.Minimum = 0;
pbStatus.Maximum = 100;
}
public string Country { get; set; }
public string DBConnection { get; set; }
public string Sql { get; set; }
public void SetMessage(string strMsg)
{
lblMsg.Text = strMsg;
}
public void Process()
{
var uiScheduler = TaskScheduler.FromCurrentSynchronizationContext();
Task.Factory.StartNew(() =>
{
lblMsg.BeginInvoke((MethodInvoker)delegate
{
lblMsg.Text = "Connecting country " + Country;
});
pbStatus.BeginInvoke((MethodInvoker)delegate
{
pbStatus.Value = 30;
});
System.Threading.Thread.SpinWait(50000000);
//***********
lblMsg.BeginInvoke((MethodInvoker)delegate
{
lblMsg.Text = "executing sql for country " + Country;
});
pbStatus.BeginInvoke((MethodInvoker)delegate
{
pbStatus.Value = 60;
});
System.Threading.Thread.SpinWait(50000000);
//***********
lblMsg.BeginInvoke((MethodInvoker)delegate
{
lblMsg.Text = "sql executed successfully for country " + Country;
});
pbStatus.BeginInvoke((MethodInvoker)delegate
{
pbStatus.Value = 100;
});
System.Threading.Thread.SpinWait(50000000);
});
//System.Threading.Thread.SpinWait(50000000); // do work here
}
}

perhaps it can be starting point. Handling pause/resume depends from your needs and can be tweaked.
var cancellationTokenSource = new CancellationTokenSource();
var cancellation = cancellationTokenSource.Token;
void UpdateDatabases(IEnumerable<...> databases, CancellationToken cancellation)
{
foreach(db in databases)
{
//create as many ProgressBar instances as databases you want to update
//check if ProgressBar exist, then return it and reuse, otherwise create new
ProgressBar pb = new ProgressBar();
pb.Maximum = iterations;
pb.Dock = DockStyle.Fill;
Controls.Add(pb);
//start thread for every database/progress bar
Task.Factory.StartNew(progressBar =>
{
var start = (ProgressBar)progressBar).Value; //use last value in case of pause
Parallel.For(start, iterations,
new ParallelOptions(){CancellationToken = cancellation}
(i, loopState) =>
{
if (loopState.ShouldExitCurrentIteration)
return;
//perhaps check loopState.ShouldExitCurrentIteration inside worker method
Thread.SpinWait(50000000); // do work here
BeginInvoke((Action)delegate { ((ProgressBar)progressBar).Value++; });
});
},
pb, cancellation)
.ContinueWith(task =>
{
//to handle exceptions use task.Exception member
var progressBar = (ProgressBar)task.AsyncState;
if (!task.IsCancelled)
{
//hide progress bar here and reset pb.Value = 0
}
},
TaskScheduler.FromCurrentSynchronizationContext() //update UI from UI thread
);
}
}
//.........
//Call
UpdateDatabases(databases, cancellation)
//To suspend, call
cancellationTokenSource.Cancel();
//To resume - simply call UpdateDatabases again
cancellationTokenSource = new CancellationTokenSource();
cancellation = cancellationTokenSource.Token;
UpdateDatabases(databases, cancellation)
Update
I've reviewed your code. Take a look at the revisited code and adapt it to your needs. Main mistakes - mess with closures and creating the Progress from non-ui thread. To enable parallel processing you can use Parallel.ForEach (see MSND for possible overloads). Also the design looks little bit strange for me(you're mixing data and logic in the Progress ). From UI perspective it's also strange that progress bars will appear in order of processing but not in original order as they are in list (it will be a problem if you decide to sort the list alphabetically)
I hope it help.
main for code
private void btnStart_Click(object sender, EventArgs e)
{
Progress ucProgress = null;
Dictionary<string, string> dicList = new Dictionary<string, string>();
dicList.Add("GB", "conn1");
dicList.Add("US", "conn2");
dicList.Add("DE", "conn3");
fpPanel.Controls.Clear();
Func<KeyValuePair<string, string>, object> createProgress = entry =>
{
var tmp = new Progress {Country = entry.Key, DBConnection = entry.Value};
fpPanel.Controls.Add(tmp);
return tmp;
};
Task.Factory.StartNew(() =>
{
//foreach (KeyValuePair<string, string> entry in dicList)
Parallel.ForEach(dicList,
entry =>
{
//create and add the Progress in UI thread
var ucProgress = (Progress)fpPanel.Invoke(createProgress, entry);
//execute ucProgress.Process(); in non-UI thread in parallel.
//the .Process(); must update UI by using *Invoke
ucProgress.Process();
System.Threading.Thread.SpinWait(5000000);
});
});
}
user control code
public void Process()
{
//uiScheduler - Not used
//var uiScheduler = TaskScheduler.FromCurrentSynchronizationContext();
//The Task is not necessary because the Process() called from Parallel.ForEach
//Task.Factory.StartNew(() =>
//{
//BeginInvoke or Invoke required
lblMsg.BeginInvoke((MethodInvoker)delegate
{
lblMsg.Text = "Connecting country " + Country;
});
pbStatus.BeginInvoke((MethodInvoker)delegate
{
pbStatus.Value = 30;
});
System.Threading.Thread.SpinWait(50000000);
//***********
lblMsg.BeginInvoke((MethodInvoker)delegate
{
lblMsg.Text = "executing sql for country " + Country;
});
pbStatus.BeginInvoke((MethodInvoker)delegate
{
pbStatus.Value = 60;
});
System.Threading.Thread.SpinWait(50000000);
//***********
lblMsg.BeginInvoke((MethodInvoker)delegate
{
lblMsg.Text = "sql executed successfully for country " + Country;
});
pbStatus.BeginInvoke((MethodInvoker)delegate
{
pbStatus.Value = 100;
});
System.Threading.Thread.SpinWait(50000000);
//});
//System.Threading.Thread.SpinWait(50000000); // do work here
}

Control.BeginInvoke does not call delegate when UI function is idle

I am modifying a windows desktop application that works with some external hardware. When the user activates the hardware from the application a progress (UI) form is started. This form creates a thread that performs all of the work with the hardware. The problem comes when I try to report progress back to the UI thread. It appears that the first of my Control.BeginInvoke ("Negotiating message") works fine. However, the second one (first adjustment to progressbar) never seems to call it's delegate and as a result the application locks up on the subsequent endinvoke. I believe the issue is that the GUI is now in an idle state, but I am not sure how to fix the situation. Any help would be appreciated. Code found below:
In the UI Load Method Thread:
private void frmTwainAquire_Load(object sender, EventArgs e)
{
try
{
//Show the GUI
this.Visible = showGUI;
pbScanningProgress.Value = 0;
btnCancel.Enabled = false;
btnCancel.Visible = false;
// Set the delegates.
SetScanMessageDelegate = new SetScanMessage(this.SetScanMessageMethod);
SetRegistrationMessageDelegate = new SetRegistrationMessage(this.SetRegistrationMessageMethod);
AddScanProgressDelegate = new AddScanProgress(this.AddScanProgressMethod);
AddRecogProgressDelegate = new AddRecogProgress(this.AddRecogProgressMethod);
// Set progress bars.
pbScanningProgress.Value = 0;
pbRecognition.Value = 0;
abortScan = false;
// Create thread here!
twainInstance = new rScan.Twain();
rScanning = new rScanThread(this, twainInstance);
// Start the thread.
rScanning.tScan = new Thread(rScanning.Scan);
rScanning.tScan.Start();
}
catch (Exception ex)
{
// Error checking here.
}
}
Delegate Methods:
public void SetScanMessageMethod(string scanMessage)
{
this.lblScanMessage.Text = scanMessage;
}
public void SetRegistrationMessageMethod(string recogMessage)
{
this.lblRecognition.Text = recogMessage;
}
public void AddScanProgressMethod(int progress)
{
this.pbScanningProgress.Value += progress;
}
public void AddRecogProgressMethod(int progress)
{
this.pbRecognition.Value += progress;
}
Thread method that is giving the problem. Please note that the thread is in a different class then the previous two code blocks (both are in the UI class):
public class rScanThread : IMessageFilter
public void Scan()
{
// Set progress bar message.
IAsyncResult result;
if (frmTwainAquireInstance.lblScanMessage.IsHandleCreated && frmTwainAquireInstance.lblScanMessage.InvokeRequired)
{
result = frmTwainAquireInstance.lblScanMessage.BeginInvoke(frmTwainAquireInstance.SetScanMessageDelegate, "Negotiating Capabilities with Scanner.");
frmTwainAquireInstance.lblScanMessage.EndInvoke(result);
}
else
{
frmTwainAquireInstance.lblScanMessage.Text = "Negotiating Capabilities with Scanner.";
}
// Start the intialization of the rScan process.
bool intializeSuccess = twainInstance.Initialize(frmTwainAquireInstance.Handle);
// If the process could not be started then quit.
if (!intializeSuccess)
{
frmTwainAquireInstance.Close();
return;
}
if (frmTwainAquireInstance.pbScanningProgress.IsHandleCreated && frmTwainAquireInstance.pbScanningProgress.InvokeRequired)
{
result = frmTwainAquireInstance.pbScanningProgress.BeginInvoke(frmTwainAquireInstance.AddScanProgressDelegate, 33);
frmTwainAquireInstance.pbScanningProgress.EndInvoke(result); // Lock up here.
}
else
{
frmTwainAquireInstance.pbScanningProgress.Value += 33;
}
// Do more work after. The code never makes it this far.
} // End of rScanThread.Scan()

C# Thread dataGridView and Loading

Im trying to load a dataGridView which takes some time, so ive come up with an idea of hiding the datagridview and put an image over the top which says Loading... when finished, the image goes away and the datagrid reappears. Ive tried to do this using threading but having no luck.
Can somebody tell me if i am approaching this in the right way?
Label loadingText = new Label();
PictureBox loadingPic = new PictureBox();
private void TelephoneDirectory_Load(object sender, EventArgs e)
{
dataGridView1.Visible = false;
Thread i = new Thread(LoadImage);
i.Start();
Thread t = new Thread(LoadData);
t.Start();
}
void LoadImage()
{
if (this.InvokeRequired)
{
this.Invoke(new MethodInvoker(LoadImage));
}
else
{
loadingPic.Image = Properties.Resources.ReportServer;
loadingPic.Location = new Point(0, 0);
loadingPic.Name = "loadingPic";
loadingPic.Dock = DockStyle.Fill;
loadingPic.SizeMode = PictureBoxSizeMode.CenterImage;
loadingText.Text = "Loading, please wait...";
loadingText.Name = "loadingText";
loadingText.TextAlign = ContentAlignment.MiddleCenter;
loadingText.Size = new Size(this.Size.Width, 30);
loadingText.Font = new System.Drawing.Font("Segoe UI", 9);
loadingText.Location = new Point(0, (this.Size.Height / 2 + 10));
this.Controls.AddRange(new Control[] { loadingPic, loadingText });
loadingText.BringToFront();
}
}
private void LoadData()
{
if (dataGridView1.InvokeRequired)
{
dataGridView1.Invoke(new MethodInvoker(this.LoadData));
}
else
{
DirectorySearcher sea = null;
DirectoryEntry dir = null;
DirectoryEntry d = null;
string domainname = System.DirectoryServices.ActiveDirectory.Domain.GetComputerDomain().Name;
domainname = domainname.Replace(".", ",DC=");
try
{
dir = new DirectoryEntry();
dir.Path = "LDAP://DC=" + domainname;
sea = new DirectorySearcher(dir);
sea.Filter = "(&(objectClass=user)(extensionAttribute1=1)(telephoneNumber=*))";
sea.PageSize = 2000;
SearchResultCollection res = sea.FindAll();
foreach (SearchResult result in res)
{
//DO ALL MY STUFF
dataGridView1.Rows.Add(row);
}
}
catch { }
LoadDataComplete();
}
}
void LoadDataComplete()
{
PictureBox loadingGraphic = this.Controls["loadingPic"] as PictureBox;
Label LoadingLabel = this.Controls["loadingText"] as Label;
DataGridView dataGrid = this.Controls["dataGridView1"] as DataGridView;
dataGrid.Visible = true;
LoadingLabel.Visible = false;
LoadingLabel.Dispose();
loadingGraphic.Visible = false;
loadingGraphic.Dispose();
dataGridView1.Sort(dataGridView1.Columns[0], ListSortDirection.Ascending);
dataGridView1.ClearSelection();
}

Spawning threads for this might not be the best idea, you could use ThreadPool or BackgroundWorker
Loading image should be fast enough that you could just do it synchronously, so make sure you actually need to do some operation on the other thread before you actually need it.
Ask yourself questions like: what if actually my image will load later then my dataTable? ("but it loads faster every time I checked" is not an valid argument when talking about threads)
At the beginning of your methods you are using .Invoke which basically means "wait for UI thread and invoke my code on it synchronously" which bombards your whole idea.
Try something like this:
Load image synchronously
Use ThreadPool to load your DataTable in it, but without using .Invoke
When it's loaded and you need to interact with UI -> then put your code in .Invoke()
Pseudocode coud look like this:
private void TelephoneDirectory_Load(object sender, EventArgs e)
{
dataGridView1.Visible = false;
LoadImage();
ThreadPool.QueueUserWorkItem(new WaitCallback(o => LoadData()));
}
void LoadData()
{
//...Do loading
//but don't add rows to dataGridView
if (dataGridView1.InvokeRequired)
{
//Invoke only the ui-interaction code
dataGridView1.Invoke(new MethodInvoker(this.LoadDataComplete));
}
}
void LoadDataComplete()
{
foreach (SearchResult result in res)
{
//DO ALL MY STUFF
//If do all my stuff is compute intensive and doesn't require UI,
//put it before Invoke() (like here)
dataGridView1.Rows.Add(row);
}
//Rest of code
}