Only UWP apps can't handle my webcam - qt

I spotted a strange thing. I have a webcam (a4tech p-635, pretty old) which is not recognized by any UWP app, like modern skype. With standard apps, everything works like a charm. I will say even more; same code in Qt compiled with MinGW can handle this camera, but compiled as UWP, can't detect her.
Have you any ideas? I can't find anything which could be a cause. Thanks.

That is most likely caused by the camera drivers. UWP app API is great at abstracting devices and access them via the simple API, but if the webcamera is not recognized, it must be that the drivers for the camera are not providing the right interface that UWP can use.
Please check if there are newer drivers available and if you cannot install some generic driver that would make the camera work.

Related

SqLite for Uno on Native platforms - How to do it?

I'm just starting with Uno. I'm an experienced UWP developer and have done some Mac development (With Xamarin Native).
I've created an Uno solution, and have removed the WASM, WPF and Mobile target projects (only interested in UWP and MacOS)
Now I want to use SQLite in my Uno solution, and not sure how that's achieved. I cant add nuget packages to the shared project, so Im guessing that I need to create an interface class to declare the data access requirements, and then implement that interface separately in the UWP and MacOS projects.
Is this how it's done, or have I got this wrong ?
Does anyone know where on the Uno docs I can find out how to do this
Thanks
OK, I was mostly right. After reading the docs again it seems that rather than interfaces, you need to use partial classes to implement the required class across the platforms you need.
I found out how to do it here:
https://platform.uno/docs/articles/platform-specific-csharp.html

Will a Flex app run on a mobile device?

Can a Flex application that was designed for use on a PC be run on an iPad, iPhone, or Android-based mobile device?
Seems like a simple enough question. Visiting http://www.adobe.com/products/flex.html yields a picture of a dude running a (presumably) Flex application on an Android. So at first glance, the answer would appear to be "yes." End of story.
but yet…
There is so much (mis)information out there on various tech sites that suggest Flash-based technologies simply won't run on iOS or other mobile platforms. Why is this? Perhaps they mean to say that Flex won't run "out of the box" and requires a plugin? Or do they mean it won't run at all?
Every time I think I've reached a definitive conclusion, some post on SlashDot or CNET directly contradicts it. So what's the scoop? Can one take an existing Flex application and run it on iOS/Android? (I realize there are screen size issues to consider so the app might not run effectively. I just want to know if the runtimes are available on the mobile devices to allow the Flex app to launch at all.)
Sorry for the noob question. My background is WPF / HTML5. Adobe technologies are completely foreign to me.
I wrote a lot below if you'd like to read it enjoy, if not sorry for taking your valuable bytes :) I directly answered the questions up here first:
Why is this?
It's a confusing matter read below for the why details.
Perhaps they mean to say that Flex won't run "out of the box" and requires a plugin?
Or do they mean it won't run at all?
Using the flash builder tools (the bin folder in the SDK) you can compile for native desktop application, desktop web browsers, native iOS application, native Android application. Android with FlashPlayer plugin installed will show Flash content within the web browser, iOS will only run the ones compiled with AIR, not in the the web browser but as a native app.
Every time I think I've reached a definitive conclusion, some post on SlashDot or CNET directly contradicts it. So what's the scoop? Can one take an existing Flex application and run it on iOS/Android?
Yes, if using AIR and run as a native app on all three platforms (the desktop Flex API is for the most part a superset of the web Flex API), your other points about performance and form factor are valid and should be considered though. The nice thing is you can write your model/controller code in a common library in AS3 then write separate presentation layer interfaces that all share the library.
Here's the very long version:
Using the flash compiler results in "bytecode" in the form of a file with a swf extension using the swf format, you can read a ton more about that here:
http://www.adobe.com/devnet/swf.html
To interpret the file you need some sort of run-time similar to some degree to running WPF/XAML/C# within a .NET framework context (either desktop or using silverlight on the web). In the case of adobe technologies (rough equivalence):
AS3 = C#
MXML = XAML
Flex = WPF+WCF (client side RPC not server side)
Flash Player = Silverlight
AIR (Adobe integrated runtime) = .NET
Framework Redistributable .dll(s)/.so(s) for desktop OSes
(Read this list very loosely please, I know XAML is preserved in the MSIL or whatever which is different because MXML is compiled to AS3 and only if a debug flag is set on the compiler does it include the debugging symbols, there's certainly tons of differences but I think this is an easy and correct enough model to use)
On iOS the browser does not allow for plugins in the traditional sense of netscape browser plugins or ActiveX plugins. For this reason you'll not be able to execute a plugin ie flashplayer or silverlight in the browser. Since Adobe did release a flashplayer for Android devices that does run in the browser it will work on those devices in the browser, however they have essentially thrown in the towel for supporting this long term, as they have to support the majority mobile device platform, iOS, in order to remain relevant (this was I think more a collective throwing in of the towel by Google, device manufacturers, carriers, Microsoft, all just following suit and trying to make the best business decision, WebKit and V8 or SpiderMonkey can probably do 99% of what Flash can do and better in some cases and WebKit will hopefully not splinter and will remain open source... frameworks and the browsers just need to get fleshed out and stabilized).
If the user installs AIR (or the runtime is packaged with the app) then a Flex/Flash (that is stuff coded in AS3 and/or MXML and compiled to a swf) can be transcoded/packaged to be interpreted by the run-time for that device correctly (be it iOS or Android or whatever RIM did, I don't think they have AIR for Windows Phone 7 and Win8 on ARM won't support browser plugins either). Part of the confusion is possibly from the fact that Apple denied the distribution of Apps that were "cross-compiled" which kept AIR out of the list of options for iOS for a good year, just after Adobe started announcing it was usable for that purpose (kicking Adobe while their down). Another part of the confusion probably comes from real vids of people who have 1 hacked their device or 2 were able to get open source alternatives to the flash player run-time to work on their iOS device (gnash was one I'm aware of from some occasional Linux tinkering, also possibly FAKE vids).
You can run Flex applications on mobile devices, but you cannot simply run any Flex project.
In Flash Builder ( Flex Ide) or in Flash Professional you can create mobile projects. These projects generate native applications for iOS and Android.
Last time I tried, the result and the available components where less than what I expected. So, if you can, I'll much recommend you go for something like Appcelerator.com or similar, which turns HTML5/Js code into native apps. I tried them, worked a lot better than Flex.
Short answer: No
Long answer: You can use Adobe's tools to compile your Flash/Flex app for use as a native iOS app. So you won't be able to embed the app in a web page like you normally could with Flex, but you can build it as a native app. Note you have to have Flash Builder 4.5 to do this.
It won't run on iPhone as a .swf file, but it will run on Android based devices that have adobe flash installed. It will also run on the BB playbook, which also has flash.
Flex is a framework.( Anyway it is very beutiful one which even sometime looks like complete different language ).
As soon as you are building AIR application it can run on various platforms like : Windows, iOS, Android, upcomming TV's, PlayBook, even .. into the future ( maybe/hopefuly ) on Windows Phone, plus Linux ( which AIR future is not very clear anyway ( but hopefuly Adobe will reconsider ) ).
So - application created with Flash Builder 4.5+ would probably run everywhere as soon as it is AIR application.
The compilation methoods is really simple, and you almost simultaneously compiling for everything you wanna to.
And one of the most important things here - your applications will run, work, look and feel the same way you were designed on one device. Flex is the thing which is responsible for everything to looks beutiful on each platform it is running.
For instance i am compiling currently for Android, and without even test i can clearly say that it will looks and feel the same way under iOS and Windows, and it will.

Will a Qt based GUI app work on the Android OS?

If I write a Qt Gui application in c++, will it work on the Android OS?
You might be interested in this video: http://labs.qt.nokia.com/2011/02/28/necessitas/
So, yes, it is possible. Personally I would recommend always using the native platform where possible - chances are it's going to be more stable across all the various Android devices.

Which platform for mobile development?

I have to develop an application which requires Bluetooth and profile change functionality for Symbian phones. After spending sometime I found that following options:
Java: but java does not allow to change profile
Symbian C++: I read basics for Symbian C++ and created some basic stuffs. Symbian extended APIs provide simple APIs for Profile and Bluetooth (I haven't tested yet). But its required lot of efforts to grab these. Specially certificate singing problem. I want to test my application on different devices and wish to give my friends whom having different cellphones. But couldn't due to signing problem.
QT: I am still confused on this. Whether this platform capable to fulfill my requirement or not. Secondly which phone supports QT or not...
Honestly, I am bit frustrated while writing this. I am looking someone, experience in these matter, to guide me in this situation.
You can combine native C++ with Qt. Though you'll lose some of the cross-platform nature of Qt by mixing native C++ with it.
See the XQProfile example on Forum Nokia Wiki for mixing Qt and native Symbian C++ for profile changing.
Qt can be installed to practically all devices from S60 3rd Edition FP1 (S60 3.1) onwards. Newer device models ship with Qt preinstalled. Forum Nokia has device specifications that you can filter based on Qt availability.
QT (+ QML) is the language of choice going forward. I believe it is currently on the following phones: N8,C7,C6,E7. i version 4.6.1 with version 4.7 which has the QML support due shortly.
However if you need to target current and older devices then your only choice is Symbian C++.

Qt - XQAlarm in Desktop versions

I'm starting to porting an Android app to Qt. Planning to port it to MeeGo, Symbian and Linux-Windows desktop versions.
My app uses alarms in Android and I have found XQAlarm class in Qt to be very usefull, BUT its belongs to Mobile Extensions package.
Any equivalent class for desktop (Linux, Windows)? or a workarround class?
If this is for mobile extension, say Symbian, then you will have to use native OS API.
Sorry, by mistake I posted the reply here, instead of replying to : How to set alarm in qt mobility application
I was searching for similar questions on this site for "xqalarm" and got this hit.

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