Develop Reference

Problem with rendering, how can I solve it?

I have a problem with the preview of my app.
In the log file i have a few errors :
This is a group project but I am the only one encountering this problem. I just downloaded Android Studio so I did not touch anything in the settings.
Any idea?

Add constraint layout dependency in build.gradle
implementation 'androidx.constraintlayout:constraintlayout:1.1.3'

Just click the blue text that prompt in your console
or try to add these into your gradle (app level)
implementation 'com.android.support:appcompat-v7:28.0.0'
implementation 'com.android.support:design:28.0.0'
And you can update them to latest version if Android Studio tells you there's a new version.

Android Navigation Component: Fragments are not visible in drop down list when adding destination from nav_graph.xml

When I am trying to add a destination when clicking
"New destination" button, from the dropdown list I am not able to see any fragments which are already there in my project.
I also face this issue when I am trying to add a blank fragment by clicking "Create a blank destination" option from the drop down.
I tried restarting the IDE, and this Android Navigation Component Not Displaying Fragment but it doesn't resolve my issue.
Navigation dependency: implementation "androidx.navigation:navigation-fragment:1.0.0-rc02"
My project is already migrated to AndroidX.
Am I missing something? Any help would be appreciated.
Gradle dependency:
def nav_version = "1.0.0-rc02"
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'androidx.appcompat:appcompat:1.1.0-alpha02'
implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
implementation 'com.google.android.material:material:1.0.0'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'androidx.test:runner:1.1.2-alpha02'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0-alpha02'
implementation 'androidx.cardview:cardview:1.0.0'
implementation "android.arch.navigation:navigation-fragment:$nav_version"

I had the same problem.
Just use these dependencies.
//Android Navigation Architecture
implementation "androidx.navigation:navigation-fragment-ktx:2.1.0-alpha05"
implementation "androidx.navigation:navigation-ui-ktx:2.1.0-alpha05"

I had the same problem and i solved it by simply checking the superior build-gradle for the kotlin version, it may be the case if you recently updated your kotlin plugin but didnt update your code.
So in android studio in project navigation bar(ANDROID): Gradle Scripts -> build.gradle(project) -> look for buildscript - ext and update "kotlin_version" for your kotlin plugin version (this can be checked in tools -> kotlin -> Configure kotlin plugin updates)

I also had the exact same problem, I was using older library version(1.0.0-alpha05)
But as soon as I switched to
implementation "android.arch.navigation:navigation-fragment-ktx:1.0.0"
implementation "android.arch.navigation:navigation-ui-ktx:1.0.0"
Other fragments started showing up!

I am facing this issue even with version 2.2.1. I have solved this by adding the fragment in the XML code. Then I am able to add actions from the visual editor.
Example:
<fragment
android:id="#+id/test"
android:name="com.example.test.ui.test.TestFragment"
android:label="Test Label"
tools:layout="#layout/fragment_test"/>

Sometimes Fragments don't show up in the graph because classes haven't been made for them. After calling onViewCreate within a class, while returning correct inflater they show up in the graph.

Just I built and Run the project once. Then Fragments appeared as destinations in the Fragments List in NavGraph.

Could not determine artifacts for androidx.appcompat:appcompat:1.0.2: No cached version available for offline mode

Gradle Dependencies are:
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'androidx.appcompat:appcompat:1.0.2'
implementation 'com.google.android.material:material:1.1.0-alpha05'
implementation 'androidx.constraintlayout:constraintlayout:2.0.0-alpha3'
implementation 'androidx.vectordrawable:vectordrawable:1.1.0-alpha01'
implementation 'androidx.recyclerview:recyclerview:1.0.2'
implementation 'androidx.cardview:cardview:1.0.0'
implementation 'com.hendraanggrian.material:collapsingtoolbarlayout-subtitle:1.0.0'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'androidx.test:runner:1.1.1'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
Gradle Project Sync failed every time after clean and rebuild.

To resolve this issue please Turn off Gradle offline mode.
Just go to (android studio 3.6 and above)
View -> Tool Window -> Gradle -> Toggle Offline Mode Icon
Click here to see the Toggle Offline Mode Icon

Gradle is in offline mode, which means that it won't go to the network to resolve dependencies.
Go to Preferences (File->Settings->Build, Execution, Deployment) -> Gradle and uncheck "Offline work".

if gradle global settings is set to offline work ,android studio will not be able to resolve this for you
To Resolve this
Go to preferences
Build,Execution,Deployment
Gradle
Global gradle settings
Uncheck offline work
Then Rebuild your project/Try sync
Make sure you have a working internet connection else possibly not work

enter image description here
Go to build.gradle(:app) and change
implementation 'androidx.appcompat:appcompat:1.4.0'
to
implementation 'androidx.appcompat:appcompat:1.3.1'
as shown in the diagram

Go to settings then search for gradle. Here are 2 status:
Your gradle is set to work offline(by checkbo
Your gradle path is not set correctly(if there wasn't problem before)
If all thing is ok then search proxy in setting page and check them. You can also check your connectivity here.
These 3 ways may solve the problem.

Android Studio 3.1.3 render fail, missing styles, failed to insantiate one or more classes

I wanted to get started with learning to code for android devices and for this i've bought a course on udemy. Unfortunately after the third video I couldn't go on because of some very annoying problems in the Android studio version 3.1.3. I tried to solve the problems but since i'm just a very beginer in programming and espacially in java I didn't stand a chance to solve it on my own and sadly every solution which i've found on the internet didn't function. So here is my problem.
Every time I start a project (no matter which) the layout won't load. And then I get this 4 messages.
Pic 1
Pic 2
I think the render problem is because of the missing styles and the missing styles are because of the classes which failed to instantiate. I think the private ressources problem is independent. So I really have no clue how to solve this problem. I think i tried almost everything. Is it possible that it has something to do with the java development kid? I've downloaded the newest version but I'm not sure if Android Studio is using it. Or maybe something with the normal java software is wrong.
Maybe the build.gradle will help you to find a solution:
pic 3
I really appreciate your time and your answers and if you need some further information please let me know.
Thank you and kind regards
Gmunderos7
UPDATE:
I've downloaded both versions on this website:
https://developer.android.com/studio/preview/?utm_source=android-studio
And both of them don't have this problems (just the private ressource). Would you recommend using one of the versions (or maybe an older version than 3.1.3 which don't has this problems)?
And can someone even use version 3.1.3 without such problems?

Step 1: "File" -> "Invalidate caches / Restart" -> "Invalidate"
Step 2: "File" -> "Close project"
Step 3: In launcher window delete your project
Step 4: Open your project by "Open an existing Android Studio project"
Step 5: Write nice code :)

I had the same problem and i fixed it today, I changed my dependencies into these
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:27.1.1'
implementation 'com.android.support:cardview-v7:27.1.1'
implementation 'com.android.support:design:27.1.1'
implementation 'android.arch.core:runtime:1.1.1'
implementation 'com.android.support.constraint:constraint-layout:1.1.2'
implementation 'com.firebaseui:firebase-ui-firestore:4.1.0'
implementation 'com.android.support:recyclerview-v7:27.1.1'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
compile 'com.google.firebase:firebase-core:16.0.0'
apply plugin: 'com.google.gms.google-services'
}

I can't see "hello world" [duplicate]

This question already has answers here:
Why textView "Hello world!" isn't showing on screen?
(3 answers)
Closed 4 years ago.
I'm learning how to build an app through Android Studio. According to the tutorials, I'm supposed to see "Hello World" when I select Activity main/ Design. Instead, it's blank and when I add a button doesn't show anything in the design.
Did I miss anything? I checked different YouTube videos and forums, I couldn't find a response. How can I fix it?

As we both can see, in the upper right corner of your screen there is a red circle error indicator. Click on it and it will pop up a screen were the respective error is explained.
If there are any errors of syntax or stuff like that, it will provide short descriptions of where the error is located and how to solve it. If not, sometimes the program has some bugs and a "Refresh Layout" button will appear in the error log. Click on that and it might solve the problem.
You can also go in File > Sync With File System and File > Sync Project With Gradle Files
Hope this helps

Go to Gradle Scripts and inside Gradle Scripts changes the dependencies for these:
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:28.0.0'
implementation 'com.android.support.constraint:constraint-layout:1.1.3'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}
Or just change the implementations:
implementation 'com.android.support:appcompat-v7:28.0.0'
implementation 'com.android.support.constraint:constraint-layout:1.1.3'
I think that it happens for the version of android.