I'm just looking into CefSharp and am confused about NewScreenshot. I've found lots of references to it as well as example code, but none of it works. I found it marked as obsolete in the 63.0 docs...
Has NewScreenshot been removed? If so, what replaces it (how can I tell that the screen has rendered)? For my purposes a blocking (non-async) method would work fine.
Update:
Searching the source for the latest version of CefSharp I find no reference to NewScreenshot.
I started with the Minimal Example that #amaitland referred to. I made a few changes, adapting it for my use. As part of that change I moved the Shutdown() call to the program's destructor.
When I ran the project I received a mystifying error about calling Shutdown() from a thread different than the thread from which Initialize() was called.
Looking through the code I saw ScreenshotAsync and, as I wasn't (knowingly) using another thread, suspected it may be involved. I looked for another way to get my SVG image and found NewScreenshot. Which of course didn't solve my problem, which was that the GC was running my destructor in a different thread (I had no idea that could happen).
At any rate, by this time I'd shucked ScreenshotAsync for NewScreenshot which is how I ended up here.
I set a breakpoint in my handler (which I haven't included as it's never called). Here's what I hope is the relevant code. I've omitted the init code but I believe it's unchanged from the example.
public static void Main()
{
private const string url = "https://www.google.com/";
browser = new ChromiumWebBrowser();
browser.Paint += OnBrowserPaint;
browser.Load(url)
Console.ReadKey();
}
In stepping through the code in the debugger, I set a breakpoint on browser.Load(url). If I examine browser.Paint, I find errors:
Here's the tooltip for DeclaringMethod:
I have no idea if this is related to my event handler not firing, but want to point it out in the event it is involved.
I appreciate your other suggestions but feel I need to find out why an event that should be firing is not.
I'll be happy to reduce and upload the project if it will help. Oh, and thanks for your help!
Related
I'm working on a new piece of code at work to assist the rest of the programmers in making app server calls. Previously we just had a .i file and relied on the developer to make sure you made all the right calls and cleaned up the app server connection at the end of the program. Obviously some people have forgotten to do that in the past and it's caused problems for us.
I've been building a basic appserver.cls file, but I can't figure out how to get it to disconnect at the end of the program.
I've tried the following things so far.
ON CLOSE OF THIS-PROCEDURE
DO:
clAppServer:cleanupAppServer().
END.
This doesn't seem to fire at the end of the webspeed call.
DESTRUCTOR appserver():
cleanupAppServer().
END DESTRUCTOR.
This works when it does garbage collection, but Progress doesn't seem to do garbage collection at the end of a webspeed call and the objects are still in memory (which is an entirely different issue that I need to deal with).
ON CLOSE OF SESSION:LAST-PROCEDURE
DO:
clAppServer:cleanupAppServer().
END.
This doesn't even compile obviously.
I've tried a whole bunch of other things that are variants on these three to no avail.
Is there any way to do what I'm asking? Bonus points if it can be inside the appserver.cls file.
If I understand the question, you want to disconnect from another AppServer once the work is done. Would try something along the lines of the below work?
Create a AppServer-handle-wrapper class. This class is responsible for the A/S connection; it has a public "Handle" (or similarly-named) property that you can use to run stuff on the AppServer.
In this class' destructor you can add code that does your clean-up : disconnect and delete server handle .
Code that wants to run something on the AppServer does something like ...
def var asConn as AppServerConnection.
asConn = new AppServerConnection().
run foo.p on asConn:Handle (param1, out param2).
// cause GC
asConn = ?.
// manually destroy
delete object asConn.
The destructor will then do the right thing.
Note that if you have this code in an internal procedure or method, then the variable would go out of scope at the end of it, and the GC would kick in.
There's an example of this approach at https://github.com/consultingwerk/ADE-Sourcecode/blob/566ac0a6e085d6305a8f364f13a1d805d3597d2a/src/netlib/OpenEdge/Net/ServerConnection/ClientSocket.cls
Bear in mind that in the ClientSocket is that the handle is private - you may want to make it public for a general AppServer connection.
This is the code,
void MainWindow::start() { //a slot that responds to a button press
//...
trayIcon->setVisible(true);
trayIcon->showMessage(tr("Foo"),
tr("Foo fooo foooo fooooo foooooo baaaaar"),
QSystemTrayIcon::Information,
1000);
//...
}
But I don't see the message immediately after the button is pressed - it shows up after several seconds; sometimes it even doesn't show up at all. First, I tried removing all other statements in the function. But it didn't work. I tried QApplication::processEvents(); too, but in vain. I Googled but couldn't come up with any relevant solution. Does anyone know how to find out what's the problem?
What operating system do you use? According to the showMessage documentation:
Note that display of messages are dependent on the system
configuration and user preferences, and that messages may not appear
at all. Hence, it should not be relied upon as the sole means for
providing critical information.
Under Linux it works as expected. You could try calling qApp->processEvents() after the showMessage call.
Regularly during my application run, I get
TypeError: Error #1009: Cannot access a property or method of a null object reference.
at mx.managers::SystemManager/stageEventHandler()[C:\autobuild\3.4.0\frameworks\projects\framework\src\mx\managers\SystemManager.as:5649]
This is the full stack trace. Obviously, I guess there is something wrong, but I can't understand what.
Is there any way for me to find the origin of that bad behaviour ?
EDIT
Having added my SDK sources to my debugger, I can now say precisely which line it is :
private function stageEventHandler(event:Event):void
{
if (event.target is Stage)
mouseCatcher.dispatchEvent(event); // This is line 5649
}
mouseCatcher is indeed null. The current event target is indeed a Stage object, and event type contains the "deactivate" String. As event occurs at application startup (before I try to do any kind of user interaction), I guess it's a kind of initialization bug, but where ? and why ?
Look at the source code, this is always your best option. The 3.4 SDK is open source (datavisualization and the flash player itself aside) and you probably already have the source for it in your FlashBuilder/FlexBuilder install/sdks folder. Use grep or windows grep to find the file in question (or find, whatever floats your boat). Open the SystemManager file and check what's happening at that line, check for calls to the method (if it's public use grep again, if it's private you just need to look within the SystemManager). Try to understand why it gets to this point, as pointed out by some others it's likely a timing related issue where you're trying to access something before it has been assigned, in this case the SystemManager, you probably need to defer whatever action you're taking that is causing the error to a later part of the life-cycle (if you're using initialize event or pre-initialize try on creationComplete instead since that will be dispatched after the createChildren method is called).
Note: Mine is located here
C:\CleanFS\SDKs\flex\3.4.0.9271\frameworks\projects\framework\src\mx\managers
In my copy of SystemManager with the version of the SDK I have that line number doesn't make any sense since it's a block closure not an executable line so you'll have to look at your specific version.
It looks like you are using the Flex 3.4 SDK. Are you listening for the ADDED_TO_STAGE event when the application loads? Or doing anything with the Stage object on load? If so, you might be hitting a bug specific to the 3.4 SDK:
http://bugs.adobe.com/jira/browse/SDK-23332
The most obvious solution is to swap out the 3.4 SDK for a later version (3.4A, 3.5 or 3.6). You can do that here: http://opensource.adobe.com/wiki/display/flexsdk/Download+Flex+3
All of your code should be backwards compatable with the newer Flex 3 SDKs.
In my AIR application (with mate-Framework) i did follwing things:
click on a button
call a method in my model "onApplicationBusy"
apply some filter in arraycollections.
In my onApplicationBusy there is this code:
FlexGlobals.topLevelApplication.enabled = false;
FlexGlobals.topLevelApplication.
I trace every step and all methods are called in right order.
But my application never becomes disabled.
Why. Is there a method for this purpose.
I try InvalidateDisplayList or ValidateNow or callLater. But all tries won't work. Probably i try it on the wrong place?
I assume, my application is so busy while applying filters (4 values for 10.000 lines) that the disabled property can't processed.
If i call the method without applying the filters all works fine.
If i call just the disbaled property but never enable the app again, the app will shown as disabled after applying the filters. for me too late.
What i origin want is a clear behavior, when the app is busy and when not (ready for clicking on buttons and all this stuff).
If you can help me or know a method, how can i shown a busy application, please help me
Thanks
Frank
All right, the setTimeout Method solve my issue. I assume, I have to wait for the next screen refresh.
Why callLater won't work and when i have to implement those functions, because i have too less ressources while my filterFunction is running?
Frank
I'm using FlexGlobals.topLevelApplication.stage.mouseChildren = false | true;
Worth noting that I first tried setting the mouseEnabled flag but found various visual elements would not update at all while mouseEnabled = false.
I am using MVVM Light and am using Messages to communicate between ViewModels to let a ViewModel know when it is ok to execute something. My problem is that I register for a message and then it receives it multiple times. so to keep from my program executing something more than once I have to create boolean flags to see if it has already been recieved. Any idea why it does this and how I can stop it?
Make sure you unregister your message handlers once you do not need them anymore. The Messenger keeps a reference to the registered methods and this prevents them from being garbage collected.
Therefore, for ViewModels: make sure that you call Cleanup once you done (or implement IDisposable and call Cleanup from there).
For Views (Controls, Windows, or similar) call Messenger.Unregister in an event that occurs on the teardown of the view, e.g. the Unloaded event.
This is a known behaviour of the MVVM and has been discussed in several places.
Very old question but I solved the problem by doing this:
static bool isRegistered = false;
and then, in the constructor:
if( !isRegistered )
{
Messenger.Default.Register<MyMessage>(this, OnMessageReceived);
isRegisterd = true;
}
I have seen this issue before. It had to do with the Messenger.Default.Register being called more than once. The MVVMLight Messenger class will register the same item 'x' number of times. This is why when you call the Send you get it many times.
Anyone know how to prevent MVVMLight from registering multiple times?
really old but thought I would answer just in case somebody needs it. I was fairly new to silverlight at the time and the issue ended up being a memory leak as the viewModel, which had multiple instances, was still in memory.
As other contributors mentioned, the same message is being registered multiple times. I have noticed this behavior taking place while navigating to View X then navigating back to View Z where the message is registered in the constructor of the Z ViewModel. One solution is to set the NavigationCacheMode property to Required
<Page
........
........
NavigationCacheMode="Required">