I have a please wait form in a windows application that gets rendered before a long running task, the please wait contains an animated gif that needs to "spin" during this process but I can't get this work.
I finally got the form to display correctly using the following code:
frmChooser chooser = frmChooser.Instance;
chooser.Url = this.UrlTextBox.Text;
frmBuildNotification fb = new frmBuildNotification();
fb.Show(this);
fb.Update();
Application.DoEvents();
chooser.BuildTreeView();
fb.Close();
this.Hide();
chooser.Show(this);
The GIF is contained within a PictureBox control on frmBuildNotification
I've read somewhere that you'll need to repaint the form for the image to animate, but this seems a bit tedious?
You need to keep the DoEvents message pump going and it also helps if you throw your notification form on another thread. Try this:
bool done = false;
frmBuildNotification fb = null;
ThreadPool.QueueUserWorkItem((x) =>
{
using (fb = new frmBuildNotification())
{
fb.Show();
while (!done)
Application.DoEvents();
fb.Close();
}
});
frmChooser chooser = frmChooser.Instance;
chooser.Url = this.UrlTextBox.Text;
chooser.BuildTreeView();
done = true;
this.Hide();
chooser.Show(this);
Related
I have a situation(mentioned below) due to which my selenium script is failing. Can someone help me?
I have a webpage where there is a save button, clicking on save button opens a new popup window. My requirement is to switch to the new window and click on one of the buttons(in the new window) which will automatically close the window and navigates to some other page. I have written a code which actually works fine but sometimes due to the application problem the new window is not getting closed. And due to this my script is failing. Here is the code I have used.
public void test() {
// i have two pages gets involved in this scenario
driver.get("some url"); // user is in page 1
// clicking on save button
driver.findElement(By.xpath("some xpath")).click(); // a new window opens
Set<String> winIDS = driver.getWindowHandles();
if (winIDS.size() > 1) {
Iterator<String> it = winIDS.iterator();
it.next();
String childWindow = it.next();
driver.switchTo().window(childWindow);
driver.findElement(By.xpath("some xpath")).click();
//after clicking on this button the user is navigated to page2
}
// after clicking on the button in the new window the new window gets closed and the user is navigate to page 2 as mentioned before.
// To validate if that has happened i am using the below code so that my test case flow wont be stopped. But
// the code is getting hanged at the new window as the app fails to perform the button click action on the new window.
winIDS = driver.getWindowHandles();
if(winIDS.size() > 1)
{
Iterator<String> it = winIDS.iterator();
it.next();
String childWindow = it.next();
driver.switchTo().window(childWindow);
driver.close();
//i m making the test failed here as the new window is not closed.
}
}
Looking at your code, I can see that you do twice the iteration to next window:
it.next();
String childWindow = **it.next();**
The second it.next() is obsolet.
Hope this solvs your issue.
I have to implement busy indication and progress reporting. The constraint is, that I have to use the provided Control Library, which offers a Window for progress reporting.
The following code works fine, but does not block the UI, which in some times is required.
private async void StartLongRunningTask2Sync() {
var wndHandle = Application.Current.Windows.OfType<Window>().SingleOrDefault(x => x.IsActive);
if (wndHandle == null)
{
return;
}
IntPtr windowHandle = new WindowInteropHelper(wndHandle).Handle;
var progressWindow = new ProgressBarCustomized(windowHandle)
{
Value = 0, CanCancel = true, CanRetry = false, Thumbnail = null, IsIndeterminate = true
};
progressWindow.Show();
await Task.Run(() => this.longRunningTaskComponent.DoLongRunningTask(this.taskIterations, this.iterationSleepTime));
progressWindow.Close();
}
The following code, which blocks the UI would work so far that the dialog is opened, but the long running task never gets executed until the dialog is closed again:
private async void StartLongRunningTask2Sync() {
var wndHandle = Application.Current.Windows.OfType<Window>().SingleOrDefault(x => x.IsActive);
if (wndHandle == null)
{
return;
}
IntPtr windowHandle = new WindowInteropHelper(wndHandle).Handle;
var progressWindow = new ProgressBarCustomized(windowHandle)
{
Value = 0, CanCancel = true, CanRetry = false, Thumbnail = null, IsIndeterminate = true
};
progressWindow.ShowDialog();
await Task.Run(() => this.longRunningTaskComponent.DoLongRunningTask(this.taskIterations, this.iterationSleepTime));
progressWindow.Close();
}
So I tried with this approach:
private async void StartLongRunningTask2Sync() {
var wndHandle = Application.Current.Windows.OfType<Window>().SingleOrDefault(x => x.IsActive);
if (wndHandle == null)
{
return;
}
IntPtr windowHandle = new WindowInteropHelper(wndHandle).Handle;
var progressWindow = new ProgressBarCustomized(windowHandle)
{
Value = 0, CanCancel = true, CanRetry = false, Thumbnail = null, IsIndeterminate = true
};
Task.Run(() => progressWindow.ShowDialog());
await Task.Run(() => this.longRunningTaskComponent.DoLongRunningTask(this.taskIterations, this.iterationSleepTime));
progressWindow.Close();
}
When doing this, I get the following error:
The calling thread cannot access this object because a different thread owns it.
After investigation of the custom progress window I found out, that the call "base.ShowDialog()" throws this error.
Is there a way to do what I like or do I have to do this with a totally different approach?
Best regards
UPDATE:
Yes, I have searched for this error and yes, I have tried several approaches with Dispatcher.Invoke() etc...
So the "real" question:
How can I show a blocking Window when a long running task is running and closing it after the long running task has finished and, eventually, inform the window about the progress of the action. The solution should (preferably) work with the MVVM pattern and not rely on (too much) code behind.
So the "real" question: How can I show a blocking Window when a long running task is running and closing it after the long running task has finished and, eventually, inform the window about the progress of the action.
You've already got most of the pieces; you just need to put them together.
How can I show a blocking Window
All UI should go on a single GUI thread. This isn't strictly necessary, but it's a great simplifier and works for the vast, vast majority of applications. A "blocking Window" is known in the UI world as a "modal dialog", and you show one by calling ShowDialog.
// Start the long-running operation
var task = LongRunningOperationAsync();
// Show the dialog
progressWindow.ShowDialog();
// Retrieve results / propagate exceptions
var results = await task;
closing it after the long running task has finished
For this, you need to wire up the completion of the task to close the window. This is pretty straightforward to do using async/await:
async Task DoOperationAsync(ProgressWindow progressWindow)
{
try
{
await LongRunningOperationAsync();
}
finally
{
progressWindow.Close();
}
}
// Start the long-running operation
var task = DoOperationAsync(progressWindow);
// Show the dialog
progressWindow.ShowDialog();
// Retrieve results / propagate exceptions
var results = await task;
inform the window about the progress of the action
Assuming your operation is using the standard IProgress<T> interface for reporting progress:
async Task DoOperationAsync(Window progressWindow, IProgress<int> progress)
{
try
{
await LongRunningOperationAsync(progress);
}
finally
{
progressWindow.Close();
}
}
var progressWindowVM = ...;
var progress = new Progress<int>(value =>
{
progressWindowVM.Progress = value;
});
var task = DoOperationAsync(progressWindow, progress);
progressWindow.ShowDialog();
var results = await task;
Another common use case to consider is the cancelling of the operation if the user closes the progress dialog themselves. Again, this is straightfoward if your operation is already using the standard CancellationToken:
async Task DoOperationAsync(Window progressWindow, CancellationToken token, IProgress<int> progress)
{
try
{
await LongRunningOperationAsync(token, progress);
}
catch (OperationCanceledException) { }
finally
{
progressWindow.Close();
}
}
var progressWindowVM = ...;
var progress = new Progress<int>(value =>
{
progressWindowVM.Progress = value;
});
var cts = new CancellationTokenSource();
progressWindow.Closed += (_, __) => cts.Cancel();
var task = DoOperationAsync(progressWindow, cts.Token, progress);
progressWindow.ShowDialog();
var results = await task;
The solution should (preferably) work with the MVVM pattern and not rely on (too much) code behind.
MVVM works great within a single window. As soon as you start trying to data-bind window-level actions and attributes, a lot of it falls apart. This is not due to MVVM being a poor pattern, but rather just that a lot of MVVM frameworks do not handle this well.
The example code above only uses data binding to report progress to the progress dialog. If your MVVM framework can data-bind the showing/hiding of a modal window, then you could use my NotifyTaskCompletion type to drive that. Also, some frameworks have a more elegant (MVVM) way to handle Window.Closed, but the details depend on your framework.
The calling thread cannot access this object because a different thread owns it.
This is a very common error and if you had searched online, you would have found a very simple explanation.
You cannot manipulate UI objects on a non UI thread.
The solution is simple. Don't attempt to open a dialog Window on a non UI thread.
Perhaps if you can clarify what your actual question is (by editing your question, not by commenting), then I can help further?
I think I have found a nearly working solution here:
Create MVVM Background Tasks with Progress Reporting
The only thing I have to get around with is the deactivation of the main window when showing the dialog.
I know there is a bunch of threads about initializing stuff in a different thread so you dont need to freeze your UI. But in my case this initialization involves creating a lot of plots (polylines in a canvas) so it seems to need to freeze the UI.
It could be good enough to hide the frame where things are being initialized (I already let a "loading.." message in below) and freeze the UI then (couple of seconds) and then show again the frame.
This is what I have so far. But is not working... it freezes the UI before hiding nothing and it unfreezes after loading the fully initializes frame.
Otherwise the thing works like a charm.
void Historics_showExperimentResults(object sender, EventArgs e)
{
aepPage = new AEPPage();
resultsPage = new AEPResultSet();
// I try to hide the frame. Below there is a "Loading..." nice text.
// not sure if it's the best way but it works if I dont show anything at the end
ParadigmFrame.Dispatcher.Invoke((Action)delegate
{
ParadigmFrame.Content = null;
ParadigmFrame.UpdateLayout();
});
// This is the initialization that needs to have the GUI thread
//because it draw some plots and polylines
aepPage.Dispatcher.Invoke((Action)delegate
{
aepPage.init(resultSet);
});
//Then I want to go and visualize the initialized page with the plots
ParadigmFrame.Dispatcher.Invoke((Action)delegate
{
ParadigmFrame.Navigate(aepPage);
});
}
Any clue??? As I said I tried to put the init in a different thread and add a event when finished, but this threads needs the control over the UI for initializing the polylines in the canvas so .. it doesn't work :(
Thanks in advance !
It looks like Historics_showExperimentResults is already running on UI thread. Try this:
void Historics_showExperimentResults(object sender, EventArgs e)
{
aepPage = new AEPPage();
resultsPage = new AEPResultSet();
new Thread(_ =>
{
// I try to hide the frame. Below there is a "Loading..." nice text.
// not sure if it's the best way but it works if I dont show anything at the end
ParadigmFrame.Dispatcher.Invoke((Action)delegate
{
ParadigmFrame.Content = null;
ParadigmFrame.UpdateLayout();
});
// This is the initialization that needs to have the GUI thread
//because it draw some plots and polylines
aepPage.Dispatcher.Invoke((Action)delegate
{
aepPage.init(resultSet);
});
//Then I want to go and visualize the initialized page with the plots
ParadigmFrame.Dispatcher.Invoke((Action)delegate
{
ParadigmFrame.Navigate(aepPage);
});
}).Start();
}
I won´t mark this as an answer since it is not .. but still is the workaround I´m using right now.
What I did is split the fade out, the init and the fade in into pieces.
I created a storyboard, fade out and attach the next step to the Finished event so, in some kind of pseudocode it would be:
StoryBoard sb = new StoryBoard;
OnClick(object sender blabla)
{
storyBoard.add(fade out animation over ParadigmFrame);
storyBoard.Completed += performInit;
storyBoard.Begin();
}
So this part is executed and the paradigmFrame disappears showing the ¨Loading...¨ message that´s bellow.
Then ..
private blabla performInit()
{
aepPage.Dispatcher.Invoke((Action)delegate
{
aepPage.Finished += initFinished;
aepPage.init(resultSet);
});
}
For sure I created the Finished event in my aepPage class and fired it when the initialization is finished. So during all this process the UI is freeze. The "Loading..." message is visible and it is not awful but the REAL solution should not freeze the UI in here...
And then I show it up
private void initFinished()
{
storyBoard.add(fade in animation over ParadigmFrame);
storyBoard.Completed -= performInit;
storyBoard.Begin();
}
This is my long and ugly workaround ... I´m still open to new solutions !!!
Thanks !
I have a Silverlight 5 application that uses ImageTools for Silverlight to save a Canvas to a PNG image. I understand that I need to work with the Canvas on the UI thread and have the following code, which works:
if (saveFileDialog.ShowDialog() == true)
{
var stream = saveFileDialog.OpenFile();
writeableBitmap.Dispatcher.BeginInvoke(delegate
{
ExtendedImage extendedImage = writeableBitmap.ToImage();
new PngEncoder().Encode(extendedImage, stream);
});
}
The problem is that if the Canvas is very large it can take a noticeable time for the code in the BeginInvoke to complete. Since this is running on the UI thread it freezes the browser window during its execution.
After the user selects the location of where to save the exported image, I'd like to popup some child window that tells the user, "Please wait...", then run the image saving code posted above, and afterwards hide the child window automatically, but I'm not having much luck accomplishing that.
For starters, the BeginInvoke code runs asynchronously, so how do I know when it has completed?
If you need to call ToImage() on the UI Thread thats fine, but it doesnt mean you have to encode the image too.
Something like this will ensure the UI stays responsive.
if (saveFileDialog.ShowDialog() == true)
{
using (var stream = saveFileDialog.OpenFile())
{
writeableBitmap.Dispatcher.BeginInvoke(delegate
{
ExtendedImage extendedImage = writeableBitmap.ToImage();
System.Threading.ThreadPool.QueueUserWorkItem(item =>
{
new PngEncoder().Encode(extendedImage, stream);
});
});
}
}
I've created a busy indicator - basically an animation of a logo spinning. I've added it to a login window and bound the Visibility property to my viewmodel's BusyIndicatorVisibility property.
When I click login, I want the spinner to appear whilst the login happens (it calls a web service to determine whether the login credentials are correct). However, when I set the visibility to visible, then continue with the login, the spinner doesn't appear until the login is complete. In Winforms old fashioned coding I would have added an Application.DoEvents. How can I make the spinner appear in WPF in an MVVM application?
The code is:
private bool Login()
{
BusyIndicatorVisibility = Visibility.Visible;
var result = false;
var status = GetConnectionGenerator().Connect(_model);
if (status == ConnectionStatus.Successful)
{
result = true;
}
else if (status == ConnectionStatus.LoginFailure)
{
ShowError("Login Failed");
Password = "";
}
else
{
ShowError("Unknown User");
}
BusyIndicatorVisibility = Visibility.Collapsed;
return result;
}
You have to make your login async. You can use the BackgroundWorker to do this. Something like:
BusyIndicatorVisibility = Visibility.Visible;
// Disable here also your UI to not allow the user to do things that are not allowed during login-validation
BackgroundWorker bgWorker = new BackgroundWorker() ;
bgWorker.DoWork += (s, e) => {
e.Result=Login(); // Do the login. As an example, I return the login-validation-result over e.Result.
};
bgWorker.RunWorkerCompleted += (s, e) => {
BusyIndicatorVisibility = Visibility.Collapsed;
// Enable here the UI
// You can get the login-result via the e.Result. Make sure to check also the e.Error for errors that happended during the login-operation
};
bgWorker.RunWorkerAsync();
Only for completness: There is the possibility to give the UI the time to refresh before the login takes place. This is done over the dispatcher. However this is a hack and IMO never should be used. But if you're interested in this, you can search StackOverflow for wpf doevents.
You can try to run busy indicar in a separate thread as this article explains: Creating a Busy Indicator in a separate thread in WPF
Or try running the new BusyIndicator from the Extended WPF Toolkit
But I'm pretty sure that you will be out of luck if you don't place the logic in the background thread.
Does your login code run on the UI thread? That might block databinding updates.