I'm setting a global variable to null before navigating to the mainpage and in the mainpage I check to see if that variable is null of not, but It isn't.
It seems to be behaving correctly when I slow down the execution using breakpoints.
Otherwise Doing a
NavigationService.Navigate(new Uri("/MainPage.xaml", UriKind.Relative));
straight after setting something in app just makes that not work.
Are there any considerations that I am missing, because I fear that the issue could be anywhere in the app (i've looked for anything that sets it back, and there's also nothing running in between Navigate and it landing on MainPage
You could try using on the mainPage, OnNavigatedFrom page event and under that change the value to Null. Also Handle your app with Tombstoning appropriately and back up persistent Data, Even have it load that Persistent Data when you navigate to a new page and then check to make sure that valued reference is Null.
I do hope this helps you, i have recently had an issue similar.
Related
I have built a class library that acts as a GUI framework that can be inherited by other projects. This application is based on projects Wild and Gemini.
My problem is that upon restoring Avalon Dock's layout using the standard serializer
var layoutSerializer = new XmlLayoutSerializer(manager);
where manager is type DockingManager. The manager restores and empty tab. My guess is that Caliburn Micro cannot find the stored ViewModel (named HomeViewModel). However, I am struggling to confirm this.
I believe my bootstrapper to be correct and that the MEF containers are being setup correctly to allow resolution of external types. I have debugged the project to a point where I think this issue is occurring and in the output window I can see Attach(Home) where the attach is occurring (note, "Home" is the display name of the HomeViewModel). However, I don't know what is wrong with the attach process as this is handled by MEF/Caliburn.
I am really stuck with debugging this an wondered if
Any one could offer any insightful advice as to how to proceed with the debugging process?
Anyone would be willing to take a look at the solution?
I have spent a hell of a lot of time debugging this without any luck and the problem is sufficiently esoteric and illusive as to render most posts here irrelevant to me.
Thanks for your time.
as discussed and after looking on the sample code provided, I understand that the following
HomeViewModel or can say LayoutItemBase is not supposed to be reopened as ShouldReopenOnStartup is set to false
if you close the application while leaving a document open for HomeViewModel it is restored on next start with blank view [Not OK]
Analysis
the SaveState method was correctly honoring ShouldReopenOnStartup value and was not emitting the state for the HomeViewModel but dock manager was still emitting an element for the document.
So upon next restart the LoadState does not find any stored state but a window was created as an element was present in the dock manager's layout state
<LayoutDocument Title="HomePP" IsSelected="True" IsLastFocusedDocument="True" ContentId="d716f824-cfff-4b54-8fd6-2d026a99369a" .../>
you did try to use e.Cancel property of Serialization callback to cancel the event, but seems like it is not supposed to prevent of loading a window but just simply to cancel the event if not needed.
Resolution
So the ideal approach is to close the documents which are not supposed to be restored before saving the layout
here is how I did
ShellViewmodel.cs : Line 279 method SaveState(string)
change the following code
if (!item.ShouldReopenOnStartup)
continue;
to
if (!item.ShouldReopenOnStartup)
{
//this item is not supposed to be restored so close the window before saving layout
IDocument doc = item as IDocument;
if (doc != null)
CloseDocument(doc);
continue;
}
I need to setup a quite huge Application with arround >20 main views plus forms. A mainview will at least contain one grid but can contain upto ten grids. There are also some mainviews that contains a Portal-Panel.
Now it comes that it take quite some time till a mainview opens which don't happends as I tested it with just one instead of >20. The Application lays within a Viewport with fit layout which holds a container with Borderlayout. The Mainview always render within the center while the other regions are used for navigation.
My first approach caching things within a tabpanel
My first approach was to got with a Tab-Panel with hidden tabs. Parallel to that I manage a MixedCollection where I make lookups if the View has already been inserted into the tabpanel or has to be created. If it has already been inserted I fetch the positon from the MixedCollection and run the setActiveTab(). But it seems worthless cause it takes all the same time to insert a new mainview or to activate a existing with setActiveTab().
So what I am doing wrong and how can I make this better?
Edit
The problem seems to come from the rendertime and that the component seems to get reredenred each time setActiveTab() is used. It takes up to 2-3 secs to render a view into the center panel. Therefore I thought I can be speed it up by caching a already created view so that the rendering and sizing didn't need to be done. I guess I should mention that in the north region a menu is also rendered each time, which not get's chached but that shouldn't matter, shouldn't it?
How the views are switched
I have a extra controller that manages the menue-view and the main-view changes. For that the menue gets removed from the container and the new menue is added and for the main-view a lookup is done in the mentioned mixed-collection if the view has already been created and if so the tab-index is received and the tab activated. If not the view get added as new tab and is afterwards added with it's ident and index to the mixed collection.
It may help you to take a look at suspendLayouts() and resumeLayouts()
You run Ext.suspendLayouts(); before you begin changing the views and Ext.resumeLayouts(true) after you are done with all views.
You should also check for overnesting, meaning you have nested to much components into each other.
Example:
If a grid is the only component within a tabpanel then it would be overnesting if you place that grid in a extra panel and then into the tabpanel.
Firstly what I found that non active tabs will be populated anyway. I don't know why. But my stores for not active tabs loaded anyway.
Second, it is really doesn't matter the size of your app. We have a lot of views and everything works pretty fast.
In most cases it is depends:
First is nesting - review your code. Less nesting more speed. For example instead of panel if you dont need all stuff that panel provide- use container. Because all this stuff is add more divs to your dom.
Depends how you create your view. Without your code it is really hard to say, why it is slow. Maybe you create your view every time when you open tab, or go to another view.
As mention #sra try to use suspendLayouts - it means that your browser will render your stuff only resumeLayouts, instead of rerender everything everytime when you add any component.
If you use windows - use closeAction:hide instead of destroy.
Not use Ext.getCmp(). I also hear that refs can slow down application because they start searching your component from the body. But it not proved info :) Use component.down('id'), component.up('xtype') it will search only from your component not from the body.
Not create your view from controller everytime when you do something using Ext.create('Panel'). It means it will created everytime.
Use less global events because this is also slowdown your app.
It is really hard to say what is the issue in your case without code. This is only few point that can help you. But my suggestion to looking to nesting and how and where you create a view.
I'm trying to create a Wizard at runtime in VB.NET using the WPF NavigationService and I'm having some problems.
I need to add controls to the PageFunction pages at runtime which seems to involve passing arguments to the PageFunction pages when I create them (prior to navigating to them). This means that the PageFunction pages need to override the default constructor and add arguments to it. This seems to work fine.
The problem is that I also need to call OnReturn once I've navigated beyond the first page (to go back to a previous page) but the OnReturn doesn't work unless I use the default constructor on the PageFunction page it is navigating back to.
The work around I've been considering is creating some global values that the PageFunctions could acssess at runtime in their default constructor but I can't figure out how to define global variables in the MainWindow that the PageFunction pages can get access to.
Any tips or suggestions would be appretiated!
Thanks
Mike
p.s. I can also post my code if that will help.
Since posting my question I discovered that if I set KeepAlive = True on the first PageFunction it solves my problem above
I am making an asynchronous call to a web service. Since it might take a few seconds there is a status Label used to let the user know what's going on. But even though the call is async the first call seems to block for a few seconds and the status label takes too long to get updated. In WinForms I could force the label to refresh (using Update() I think) but not in WPF. Any super easy ways to get this working?
Thanks,
Gerry
You could move the entire call logic into a QueueWorkUserItem or BackgroundWorker block. That way the first proxy initialization would not block the UIThread (before the async. Begin/End pattern kicks in). Assuming that you are using databinding the object exposing the property bound to the Label implemented INotifyPropertyChanged everything should happen automagically.
I'd (wildly) guess that the blocking is due to the creation/initialization of the service proxy classes. If so, you could try to create the proxy earlier, or call your asynchronous web service in another thread.
The general answer to your question about refreshing controls... I have always relied on data binding to do this. That won't help though if the main UI thread is stuck doing something. And if the UI thread is stuck, I don't know that there's any way to get it to draw.
There isn't a way to tell the label to refresh that will actually work in your case. If the UI is being blocked, it won't refresh. Basically, when you actually get to the point where you update the label's text, it will show in WPF. The only possible exception that I can think to that would be if you are using a non-WPF control but even then it should work.
My suggestion would be to update the label before you perform the first action (even before variables are initialized, since this might be where the issue actually is). Here is a pseudocode example of what I mean (just in case I wasn't clear):
private void KickOffProcess()
{
label1.Text = "Processing ..."; //This is where you need to move the label update code
AsyncCall();
}
What could be the reasons for the Main application form not to be shown in TaskBar?
ShowInTaskbar property is set to "true", but form doesn't show itself there if after running the application and before the Main form appears I switch to some other window. Form exists, but until I minimize apps that are above to make it visible, it won't show in Taskbar.
UPDATE. Form does not have an Owner.
I've added form.Activate() after form.Show(). Now it always jumps out when completely loaded, and doesn't get lost under some other screens.
Though it is not a solution, but a crutch, responses are welcome anyway.
Check if your main form has a Parent defined or an Owner. In either case that would exclude it from being in the task bar in its own right. Also worth trying TopMost=true.
I had the same issue with one project I wrote.
No icon showing in the Taskbar unless I forced Windows to refresh it.
It was a call to
this.MinimumSize = new Size(wid, len);
In the Form_Load that was the issue.
I had a similar issue when the program was run from an installer (InstallMate in my case). I eventually pinned the problem down to changing the form's title text (Text) in the Form1_Load() method. When I moved that title changing text to just below the InitializeComponent(); bit, the problem went away.
I hope this can help someone else, despite the specificness of my circumstances.
I had the same issue as #deegee where setting MinimumSize in the Form Load causing the non display in the Taskbar. I fixed the issue with setting the Form Visible to False then to True.