Android Studio Not Recognizing Imports in TextView - android-studio

I want to watch android sources code, but Android Studio has so many errors in base Android code. How do I fix these?

Since no one has jumped in here to help with this...
The longer answer here is that the imports (in red) are failing because Android Studio can't find them. So all the calls made to those libraries are failing. So ALL your code after that is full of errors.
For instance, the android.annotation.ColorInt seems to be broken. A quick Google search provides THIS: https://developer.android.com/reference/android/support/annotation/ColorInt.html
Which tells me that the reason that dependency is broken is because whatever you have there is deprecated and should now use a new reference.
Continue with this sort of research and your problem is solved.

Related

Android studio keeps underlining all classes red while saying that R doesn't exist

I know this has been asked many times, but usually the advice is something along the lines of "decrease Android gradle plugins version" or something like that. Firstly, that doesn't seem to work for me, secondly, decreasing the version in order to solve this kind of problem doesn't seem like a good practice and I'd like to avoid it (especially since Android Studio warns me I should increase the version back again when I try to decrease it).
So now what exactly is happening + some details that might help:
Every class is underlined with red color in the project explorer and there are loads of "java package R does not exist" messages in the Problems view
When I open any class, suddenly its red underline disappears and there are actually no errors in this class
It happens if and only if AS does an automatic build (I can see "21:03 Auto build completed with errors" in the Event log). When I build manually, there are no errors in the Problems view, and no class is underlined (that is, until AS does auto build again, which happens all the time)
In any way, this doesn't prevent building of the application/APK/AAB, installing it on the phone/virtual, and running it
This has been happening ever since I updated Android Studio to v4.1 (I now use Android gradle plugin v4.1.0)
(Of course, I also tried all the obvious stuff - deleting every temporary/generated file, invalidating cache, restarting, cleaning, etc. etc. Everything I could think of.)
I had a problem like this before, it had nothing to do with the gradle ijust add "import com.package.appname.R;" into myclass and is worked

Android Studio very slow lint

I do not remember the exact version, but about from 3.2, the lint processing of Android studio has become dreadful.
ctrl + b won't work for about 5min after putting the code, and red lines which are supposed to indicate unwritten methods or wrong referencing is completely broken.
I never had such issue on the previous versions, and I don't know what to do with this. I looked through stackoverflow with the tag android-studio, but no one seems to have the same issue, or I'm selecting the wrong keyword for this.
But, all three of my colleagues are having the same issue from a certain version of Android studio.
Is this an issue with vmOption? Please help.

visual layout editor does not allow drag&drop

I'am a newby in android studio and learning a lot, but now have a problem where i cannot seem to find the answer to.
In android studio you can visualy drag&drop your screen.
I have seen it can do al lot (although you sometimes need the xml) but for me it is not working at all.
I mean i cannot drag&drop any widgets on the screen at all.
Tried changing the theme: no help (really tried a lot of them)
Tried a complete new project: same story
Tried other APK verion: same story
Tried Invalidatd caches / restart: no help
Even with a new project (EmptyActivity) it add's a android.support.v4.widget.NestedScrollView and then gives error's on that
(Failed to find style 'coordinatorLayoutStyle' in current theme).
It also gives an error on layout_height/layout_with not being there. But they are there for each widget.
Please do not missunderstand: when i execute the project i runs just fine (both on phone and emulator) but the visual builder for the screen.....:-(
Does somebody knows how to solve this.
If more info is needed please ask.
Any help is more than welcome.
There are several things that could be causing this:
Your caches could be messed up. Try going to
File > Invalidate Caches / Restart ... (I know that you already tried this, but posting for future views.)
Also, make sure that you don't have Drag-n-Drop with ALT pressed only checked in your Settings (Appearance & Behavior - Appearance).
Finally, in a default project created in Android Studio, there are two XML files created for each layout. For example, content_main.xml is embedded within activity_main.xml. Make sure that you are using content_main.xml for your design work.
In the end i fixed it by changing the SDK version in de gradle file.
still do not understand why it was wrong as studio genereded it that way but now it works so.... for me: case closed.

onAttach method crossed in Android Studio 2.3.3

I am new to android and I have been learning android from Bucky`s tutorials from youtube. I am using android studio 2.3.3. I am learning fragments and I have to use an overridden method by the name of "onAttach()",
Whenever i go for this method, its always crossed. Why is it so? Anyone?
Screenshot1
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Bucky's tutorials are extremely out of date.I can still remember watching them in 2012. The crossed mark you saw means the method you're trying to override is deprecated. This doesn't mean it wouldn't work, however it means that anytime Google may remove it and then it wouldn't work. Either way, it is your job to stay up to date. Override methods that are not crossed. And try reading more tutorials than watching videos; they tend to be more informative.
You're overriding a deprecated onAttach(Activity activity) instead of onAttach(Context context). There's a lot to read about this problem here on SO, e.g. Android Fragment onAttach() deprecated.

How to debug Android Studio Project (using NDK and JNI) line by line to see the workflow?

I was using Visual Studio and it's Debug mechanism is really useful to me. With many header and C files in 1 project, just a simple F10 it could take me a tour around from the beginning of the main() function so that I could see the sequence of the code being executed.
Now I'm jumping into Android Studio and start with a project using NDK, JNI (this project for example: https://github.com/googlesamples/android-ndk/tree/master/gles3jni), it makes me confused because there're many .java files and others C++ (native code) files and I don't know which code from which file is executed first and how it goes on.
My Question is: I'm looking for a way to debug in Android Studio line by line from the beginning to see its workflow likes how Visual Studio did but all I got from searching is how to start from a breakpoint when debugging.
I have tried putting the break point in the onCreate() method of the launcher activity and use F8 to Step Over and F7 to Step Into but it doesn't work as i expect. It keeps taking me to the super class Activity.java and GLSurafaceView.java instead of taking me to the C++ code. Is there any way to do so in Android Studio and how to do it?
I have tried with others project but the problem still remain the same. Hope someone could help.
This won't happen. Your app (the Java boilerplate code) is set to respond to many system events that happen when the user works with the app and the device on which the app is installed. If your c++ code is a piece of monolythic straightforward algorithm, you can set s breakpoint in the beginning and really follow step by step. But with Android Studio, even this process is not as easy as with Vusial Studio. To begin with, it's always remote debugging, dependent on delicate communication protocols.
This said, you can try to set up Microsoft Visual Studio as your IDE for debugging native Android code. It is surprisingly robust, and also may be more familiar to you.
Since you've asked about Android Studio, I will answer about that - I am not familiar with Visual Studio for Android and perhaps it is better for what you are asking.
In Android studio such debugging is very hard - although some people said they managed to get it to work, I wasn't able to. Especially in a complex environment. So, what I'm doing is extensive logging, with as many details as possible, and visual debugging - put some text view on the screen and update it with the info you need. This could be quite powerful in some cases. Or, alternatively, make some changes in your ui or your scene as a result of certain conditions you define - so you could see the visual effect. Again, much less useful than debugging, but can still be quite powerful.

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