Camera control Locks Camera on phone

[judithPA]

I have been having problems with the camera control in a canvas app so have stripped everything out. I now have a blank screen with a button that takes me to a second screen. On this screen there is

Camera control: Camera1

Image Control with Image Property: Camera1.Photo

Button to return to screen 1

All is fine running in a browser but on my Android phone I can go into the photo screen ok the first time but on going back to screen 1 and out again to Screen2 the camera gives the message

The camera could not be started because it is in use by another app....

Interestingly if I leave the phone on this screen and it times out, reopening the phone releases the camera.

Any suggestions please as I have been grappling with this for weeks and really need to get it working.

[Chris-D]

I've found camera controls problematic because they behave differently on different devices. 

I think the camera is turned off if it's not visible. You could try adding a variable to the 'Visible' property of the camera, and turning it on/off with the Screen's 'OnVisible' and 'OnHidden' properties. 

[judithPA]

I had  tried turning the visibility on and off when switching screens but I don't think I was doing that correctly as you mention creating a variable to do that?

How do I create the variable please and could I try changing the edit mode to disabled too?

[Chris-D]

You could try changing display mode too. Here's code for both.

We use UpdateContext() to create a variable that's only visible on this screen since we don't need to use this anywhere else. 

Screen.OnVisible:

UpdateContext({ CameraControlEnabled: true});

Screen.OnHidden:

UpdateContext({ CameraControlEnabled: false});

Then we can use this variable in the camera properties:

CameraControl.EditMode:

If( CameraControlEnabled, DisplayMode.Edit, DisplayMode.Disabled)

CameraControl.Visible:

CameraControlEnabled

[judithPA]

I think I have added this correctly

photoScreen has my camera control and on this screen

photoScreen.Visible set to     UpdateContext({CameraControlEnabled:true});

photoScreen.Hidden set to   UpdateContext({CameraControlEnabled:false});

Then the camera control is Camera1

Camera1.DisplayMode set to  If(CameraControlEnabled,DisplayMode.Edit,DisplayMode.Disabled)

Camera1.Visible  set to  CameraControlEnabled

But I still get the same issue. All fine going into photoScreen the first time but going back to screen1 and returning and the camera is locked. Do I need to set anything on the button that returns me to the first screen to clear the camera? It currently is just set

button1.OnSelect   to Back()

I have also noticed that when I am hopping in and out editing the app on the browser and testing on the phone in between, even though I have come out of the app on the phone, the app on the browser is locked in Read Only mode. I have looked at Power Apps settings on my phone, cleared the cache and the only other setting I can see is that it is set to optimize images for upload.  

I am really struggling here.

[judithPA]

I have just tried this out on an iPhone and all is OK? But Android (Samsung Galaxy) still having issues.

[Chris-D]

I've just tried this myself. I have an app which uses the camera control. My own phone is a Samsung Galaxy S9, quite old now. 

The first time I did this, when I went back to the camera screen my phone rebooted! When I tried again, it worked fine. 

I think the code you have is the best you can get. This type of fault is something to do with the Power Apps mobile app, not your app. 

You could try some delay, i.e. wait 5, 10, 20 seconds before returning to the screen and see if that works. It could be that Power Apps takes a few seconds to shut the camera down so if you try and access the camera again too quickly it could fail. 

Also something I've found with the camera control, front and rear cameras aren't always the same device number. The first property on the camera control is the camera device number. 0 is sometimes the front, sometimes the back. Sometimes there are more than 2 devices but only 2 cameras. On my S9, there are 3 camera devices but 2 of them are the front camera. 

[judithPA]

Thanks for all your help. My phone is only a Galaxy A8 so maybe just too lowly. Fortunately all my engineers have iPhones so I will go ahead and set up the app for them but really irritating that it fails on my phone. Is it worthwhile logging this with Microsoft?

[Chris-D · Accepted solution]

It's probably already known but maybe if more people report it they might fix it sooner. 

[KAdler]

Hello everybody,

experiencing the same stuff here as well. i try to repeatedly use a barcodescanner and afterwards want to take a picture which then i add to a database to the matching barcode i scanned. First run works without problems but when i try to call the camera for the second picture i always get the error, that the camera is already in use. I already tried releasing the camera by changing the camera in the camera control depending on the active screen or changing the visibility itself without success.