I just encountered an error unable to set property '_itemsCount' of undefined or null reference. There is no such property anwhere in my code, so I browsed the WinJS source and found that there is in fact a property _itemsCount used in the WinJS ListView.
The error didn't reappear, even though I tried reproducing it a number of times. Now I fear I have a Heisenbug lurking somewhere: did anyone encounter this one before? Do you have any tips how to get rid of it?
Update: I looked through the WinJS code a bit and found that _itemsCount is probably related to management of the current selection.
Related
There is one object from one class which is not getting identified during the runtime or debugging.
The same object gets highlighted on devtools. I'm not understanding what is wrong over here.
Does anyone have any idea what is the cause of this issue?
Let me know if require more details.
The reason it was not getting highlighted during runtime was because it is the part of one iframe. After pointing my webDriver to the iframe and then the object , my code was running successfully.
I am attempting to make a simple animation for a card to slide up. I have designed the card, and I found an example online for how to use the Animate.spring function. I followed that but it throws the error: attempted to assign to readonly property.
I can only assume that it is referring to the state, but I specifically changed the state from read only. I have tried searching online for a solution and every stack or git solution I find says to make sure youre using animated.values or animated.views. I am using both and it is still throwing this error. I tried restarting the app and vscode.
I'm trying to add custom content type to existing page builder module in Magento 2 following https://devdocs.magento.com/page-builder/docs/create-custom-content-type/overview.html
Bit of a problem that docs is kind of outdated, but the biggest issue for me right now, is that for some reason, panel with settings of content type is not loading. Console doesn't throw any errors and I'm not even sure how to debug this.
Normal behavior: https://drive.google.com/open?id=1OClPda-WGuc7idNogUnTz0wi4ZSk_Qu_
Behavior of custom content type (settings are not loading at all): https://drive.google.com/open?id=1I-IeTImec-M8DuLfgjiA193mhm0Fwtd8
Maybe someone already stumbled upon issue like this and know possible ways to solve it?
Ok I've found out what problem was, so I'm answering this question in case someone will need this in future.
Check your ui_component xml structure, I was having an issue with naming there (namespace was not correct), and that's why it was not loading.
I created a new blank Windows 10 Universal app and tried to add a WrapPanel exactly as per the sample code in the link: WrapPanel XAML Control
I am getting the following error message on wrapPanel:WrapPanel
The name "WrapPanel" does not exist in the namespace "using:Microsoft.Toolkit.Uwp.UI.Controls.WrapPanel"
I have already added xmlns:wrapPanel="using:Microsoft.Toolkit.Uwp.UI.Controls.WrapPanel" as per sample code.
Full code and errors (please click image for better quality):
I have tried to Clean and Build/Rebuild but it doesn't help. I also made sure that I am targeting the latest Windows 10 version:
Please help!
Update: I tried using xmlns:wrapPanel="using:Microsoft.Toolkit.Uwp.UI.Controls"
as suggested but I still get this error. Again, I tried clean and build/rebuild and am getting the a similar error:
The documentation has a typo. The WrapPanel control is not in the Microsoft.Toolkit.Uwp.UI.Controls.WrapPanel namespace, but rather just in Microsoft.Toolkit.Uwp.UI.Controls, so use the following
xmlns:wrapPanel="using:Microsoft.Toolkit.Uwp.UI.Controls"
And it should work as expected. I will push an update for the docs.
I am getting this exception, I have no clue whatsoever why it throws this ArgumentException.
Does anybody have an idea what is that can cause this exception to occur in a metro app?
Is it due to any mistake in XAML design or is it something else?
You might be setting Selector.SelectedItem in a ComboBox, ListView, etc. to a value that is not actually in the bound ItemsControl.ItemsSource collection.
Try this method, if there are no obvious issues in your code/xaml