Develop Reference

Module not specified after opening project from another computer

I keep my projects in my Dropbox folder. I installed Android Studio on my laptop and I tried to open the Project. All java files had a red circle which I managed to fix by marking the Directory as Sources Root. When I try to run the application, the Edit configuration window pops up with a sign at the bottom saying that Module is not specified, in red. There is no module I can select in the appropriate combobox. Syncing project with grandle files has no effect and importing the project instead of opening it makes things even worse. At the Projects side tab, by selecting the Android option, I can only see the Grandle Scripts structure and not the project files. The project files are visible when I select the Project option from the combobox.
The project cannot even open at the original computer anymore. I am new to Android and I have spent a lot of time developing this project. What can I do to reverse the situation?

You have to change some gradle properties.
First you open android studio and create a new project. Then change your old project's all gradle properties according to new project. like bellow--
Go to your build.gradle(Module:app) script and change the gradle version like compile 'com.android.support:appcompat-v7:25.3.1' to your current version.
Go to your build.gradle(Project:your app) script change this line classpath 'com.android.tools.build:gradle:2.3.0' to your current version.
Finally you have to change gradle-wrapper.properties(Gradle Version) distributionUrl=https\://services.gradle.org/distributions/gradle-3.3-all.zip
to your current version
Now sync your project, I hope it will working fine.

Android studio: this project is not gradle based project

I have one project which was initially in eclipse, then i managed somehow to convert it to gradle and everything was working fine in Android Studio.
But then i didn't work some time with the project and after few months when i returned to project i am surprised that Android Studio has problems with this project.
When i selected "Android" from top left dropdown in AS, where you should see the project as Android, i saw no files, then i did something and now i see there one empty folder Java.
If i hit button "sync project with gradle files" AS says message as posted in name of question, but it is gradle based project.. there are gradle files etc.
Do you someone know why is this problem? Why it should stop work like this?
Thank you

Make sure you open the project from its root directory. i.e. the directory which contains the top level build.gradle file.
The missing top level gradle file is what causes this error.

For native Flutter Projects:
Note that this error will also appear if you "sync your project with Gradle files " in the root directory. Gradle works only in your android directory (flutter_name/android).
Configure Gradle version
I got this error because i wanted to change some build values like the Gradle version and the Gradle plugin version (and other build values ex. kotlin):
In your current project: File>Open
Select directory: user/StudioProjects/flutter_name/android
Open directory in a new window
After it is opened it will load some packages (see right bottom), which will take some time.
Under File>Project Structure Project you can set the gradle version and under Modules variables of your build
Now you can sync your project with Gradle files or at least read out the error messages, that come with your configuration
After configuration, you might need to restart your project with File>Invalid Caches/Restart....

That worked for me:
copy the file build.gradle
drop the copied file build.gradle in
your app/project folder .

My project stopped showing all of sudden and already had build.gradle file.
I just reopened it via File > Open.

Android Studio - Android Project View is Missing

I've found some webpage but it does not guide me back to normal android project view.
http://developer.android.com/sdk/installing/studio-androidview.html
I did File => Other Settings => Default Project Structure => Default Settings => OK It make even worse, import library become not function-able.

I also had this problem (creating new project also looked similar to IntelliJ IDEA), got it fixed when I enabled some Android-related plugins.
Go to Preferences (Settings on Windows and Linux) > Plugins and enable Android Support, at a minimum.
Now you will have "Android" option in the Project View.

Try:
View -> Tool Windows -> Project OR the shortcut is alt+1.
If that's not working try:
Window -> Restore Default Layout OR the shortcut is shift+F12.
Also, check that Studio is up to date:
Help -> Check for update...

None of the above solutions worked for me so I fixed this by removing the .gradle and .idea folders from my project.

The square at the bottom left corner of android studio lets you spread the screen or it populates it with side menus.

For me, it happened when I used Kotlin KTS for Gradle files, but created a java library module for this project. After trying to reimport project I got an error:
New Gradle Sync is not supported due to containing buildSrc module
Solution:
Migrate added module to kts
Remove created by Wizard settings.gradle, if you already use settings.gradle.kts
Reimport project
File -> Close project
Android Studio: import project
Show it your current project location

Just had the problem happen to me again. I got the problem solved, but unfortunately I can't confirm the solution, now that it's fix; but I have strong suspicions on what was the cause.
In my case, the problem occurred as a result of reorganizing my project directory. My projects are stored in given directory lets call it "Projects". I renamed that fold to "ProjectsBackup" and created a new "Projects" directory. I then moved selected projects now contained in the "ProjectBackup" directory to the new "Projects" directory. After moving the first project, I used Android Studio to open that project. That's when the problem occurred. I got a message that it couldn't find the gradle-wrapper and offered me the choice to create it. The gradle-wrapper is stored in a directory call "gradle" and its stored in the "Projects" directory. I had not copied that directory over from the "ProjectsBackup" to the new "Projects" directory. At the time, I thought nothing about that since, a new one was created. After trying all the various suggestion in this problem discussion, android studio offered a notification from me to update my "android gradle" plugin. I did the update and after that the "android" view was now available for me to select. The android gradle update fixed the problem.
I unfortunately, can't tell you what changed as a result of the update, nor can I tell you how you can force Android Studio to update or reinstall the android gradle plugin. All I can tell you is that I got lucky that android studio gave me that notification to update the android gradle plugin. Things like "file/project structure" and changing the Android Gradle Plugin Version, didn't fix the problem. What I did notice, was that when I first looked at that, the drop-down list of android gradle versions was an empty list. I manually put one in "3.6.3", but it didn't help. If you run into this problems I would suggest you look at the dates of the two file in the "wrapper" directory and compare those to projects you may have that are working correctly with the android view. I wish I would have checked the date of the wrapper jar file, when it wasn't working. That's what I think might have been wrong (i.e. I got a wrapper.jar file that was incompatible with my version of android studio - unfortunately I can't prove that)

problem solve i have click this button

Importing library in Android Studio

I have little experience with importing libraries. I am using Android Studio, and am trying to use parse.com's library with no luck. I followed these instructions, and tried a few other things when that didn't work. Please help me out. Let me know if you need any more information. Thanks for your time.
This is my MainActivity where I would initialize my Parse client key:
Project Structure showing I have imported the libraries:
UPDATE
Gradle:
UPDATE:
When I try to Build, I get this error: Gradle: error: package com.parse does not exist
When I try cleaning through command prompt

Put the jar into the libs folder
Right click it and hit 'Add as library'
Ensure that compile files('libs/~~~~~~~~.jar') is in your build.gradle file
Do a clean build (You can do this easily in android studio but just as a better method, go to your project folder using windows explorer and open a Command window there by right clicking the folder while holding shift and type gradlew build.

To add to the answer of #ThePoloDoc and for your update Command Prompt image, you need to do the following to clear that error:
Go to Control Panel -> System -> Right Side see for Advanced System settings
Select Environmental Variables
In the new window, search for the PATH variable. Add the java installation folder something similar to C:\PATH_TO_JDK\bin
Replace the PATH_TO_JDK with the installation of your java directory
Try opening the command prompt and you'll see the error gone.
UPDATE:
I have got a doubt in your question. Why do you manually compile gradle? I use Android Studio. But I always click the Sync Project with Gradle Files button on the top. It does everything for me

What is Android Dependencies? Remove it from Build Path, ClassNotFoundException occurs

I'm working on a team project. I included a .jar file in Build Path and committed to SVN. When I updated code in my working directory, a new folder appears in Eclipse called "Android Dependencies". If I let it be there, my program runs; If I remove it, my program reports a ClassNotFoundException.
Now how to fix this ClassNotFoundException?

For the people whose heart dropped when they read the comment that deleting the Android Dependencies virtual folder will destroy your project, there is an easy fix.
Right click on the destroyed project
Select "Android Tools > Fix Project Properties" in the dropdown
I hosed my project dependencies when trying to set up my git repo, and this is fixed it.

Android Dependencies is a virtual folder where Eclipse shows what JAR files the project depends on. It's not a physical folder; you won't find it on your hard disk. And the folder is not checked in into Subversion.
Do not delete that folder. You will destroy your project.
To fix it, just revert to an older Subversion revision and check it in again.

I've had a similar problem after setting up a git repo with my project.
The problem was that the appcompat import lost its folder reference.
If the 'Fix Project Properties' mentioned doesn't work for you try this:
Go to Project > Properties
Go to the 'Android' tab
Under 'Libraries', if there's a red 'X' next to the appcompat folder, remove
it then hit 'add' and add it in again. The reference should show a
green tick now.
Save and clean the project if needs be

If you also have marked project build target below API level 16 in the Android project properties, the error is going to come because prior to this level, there was no Android dependencies.