Develop Reference

Trouble with gradle in android studio

I know about this questions:
Failed to resolve: com.android.support:cardview-v7:26.0.0 android
Could not resolve com.android.support:appcompat-v7:26.1.0 [duplicate]
Could not resolve com.android.support:appcompat-v7:26.1.0 in Android Studio new project
And I've read this documentations:
Migrate to Android Plugin for Gradle 3.0.0
Migrating to Android 8.0
So I'm posting this question believing its not a duplicate.
I've installed Android Studio 3.4.1. I didn't have any previous version before and I started a new project.
Every setting in Gradle file have been set by Android Studio itself and I've checked them all.
I have already tried
invalidate and restart android studio
Could not resolve com.android.support:appcompat-v7:26.1.0 in Android Studio new project
Failed to resolve: com.android.support:cardview-v7:26.0.0 android
These are the file contents:
build.gradle (Module:app)
apply plugin: 'com.android.application'
android {
compileSdkVersion 29
buildToolsVersion "29.0.0"
defaultConfig {
applicationId "com.example.myapplication"
minSdkVersion 28
targetSdkVersion 29
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'androidx.appcompat:appcompat:1.0.2'
implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
}
Top level build.gradle
// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
repositories {
google()
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.4.1'
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}
allprojects {
repositories {
google()
jcenter()
maven {url 'https://maven.google.com/'}
maven { url "https://jitpack.io" }
maven { url 'https://dl.bintray.com/guardian/android' }
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}
gradle-wrapper.properties
#Mon Jun 10 17:40:01 IST 2019
distributionBase=GRADLE_USER_HOME
distributionPath=wrapper/dists
zipStoreBase=GRADLE_USER_HOME
zipStorePath=wrapper/dists
distributionUrl=https\://services.gradle.org/distributions/gradle-5.1.1-all.zip
I use google() in repositories as here clearly says:
// If you're using a version of Gradle lower than 4.1, you must instead use:
// maven {
// url 'https://maven.google.com'
// }
My gradle version is 4.1 so I don't need above code.
But I still get this error as the others have been asking about:
Unable to resolve dependency for
':app#releaseUnitTest/compileClasspath': Could not resolve
androidx.constraintlayout:constraintlayout:1.1.3.
ERROR: Unable to resolve dependency for
':app#releaseUnitTest/compileClasspath': Could not resolve
androidx.versionedparcelable:versionedparcelable:1.0.0.
ERROR: Unable to resolve dependency for
':app#releaseUnitTest/compileClasspath': Could not resolve
androidx.lifecycle:lifecycle-runtime:2.0.0.
ERROR: Unable to resolve dependency for
':app#releaseUnitTest/compileClasspath': Could not resolve
androidx.legacy:legacy-support-core-ui:1.0.0.
ERROR: Unable to resolve dependency for
':app#releaseUnitTest/compileClasspath': Could not resolve
androidx.vectordrawable:vectordrawable-animated:1.0.0.
ERROR: Unable to resolve dependency for
':app#releaseUnitTest/compileClasspath': Could not resolve
androidx.fragment:fragment:1.0.0.
I have also unchecked the offline check box from gradle and using default
Why should I get this error when I'm creating a new project in AS 3.4.1 and it has been set all the necessary settings?

You are trying to mix AppCompat and Jetpack dependencies, and you cannot do that.
I think you might not have the right repository setup for the Jetpack libraries (why it can't find any Jetpack libraries).
Don't use: implementation 'androidx.appcompat:appcompat:1.0.2' . (this is Jetpack) -- use AppCompat versions of this (besides - Jetpack is NOT consistent with Appcompat versions earlier then 28.x). Bottom line, get rid of anything that says (androidx).

Define repositories for both Appcompat and jetpack
allprojects {
repositories {
google()
jcenter()
maven {url 'https://maven.google.com/'}
maven { url "https://jitpack.io" }
maven { url 'https://dl.bintray.com/guardian/android' }
}
}
After that sync project with gradle.. let me know its working or not.

Replace
implementation 'com.android.support:appcompat-v7:26.1.0'
implementation 'com.android.support:design:26.1.0'
with
implementation 'com.android.support:appcompat-v7:26.0.0'
implementation 'com.android.support:design:26.0.0'
EDIT:-
You should invalidate your cache and restart. Follow this steps file -> invalidate caches/Restart Then select invalidate and restart

Unable to resolve dependency for ':app#debug/compileClasspath': Could not resolve com.android.volley:volley:1.1.1

I tried to import android volley into my project, but it failed. I dont know what happened. This is the build.gradle file:
apply plugin: 'com.android.application'
android {
compileSdkVersion 28
defaultConfig {
applicationId "com.example.root.wifi1"
minSdkVersion 22
targetSdkVersion 28
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support.constraint:constraint-layout:1.1.3'
implementation 'com.android.volley:volley:1.1.1'
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'
}
And this is the build.gradle for project:
buildscript {
repositories {
google()
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.1.4'
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}
allprojects {
repositories {
google()
jcenter()
//maven { url "https://jitpack.io" }
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}
I have tried using volley library version 1.1.1, 1.1.0, the one from mcxiaoke, and a few other versions, but none of them worked. I also tried to switch my gradle version, and also tried to create local library using android volley that I cloned. Someone suggested to add maven { url "https://jitpack.io" } to allproject repositories, I also tried it, but it also didnt work. Of course I have also tried to disable offline gradle from Settings menu, but it didnt change anything.
this is the error :
Unable to resolve dependency for ':app#debug/compileClasspath': Could not resolve com.android.volley:volley:1.1.1.
Unable to resolve dependency for ':app#debugAndroidTest/compileClasspath': Could not resolve com.android.volley:volley:1.1.1.
Unable to resolve dependency for ':app#debugUnitTest/compileClasspath': Could not resolve com.android.volley:volley:1.1.1.
Unable to resolve dependency for ':app#release/compileClasspath': Could not resolve com.android.volley:volley:1.1.1.
Unable to resolve dependency for ':app#releaseUnitTest/compileClasspath': Could not resolve com.android.volley:volley:1.1.1.
Everytime I changed the volley version the error was just like that too.
I dont know what to do now, please help
PS: if i comment/remove the volley dependency my project works 100% fine, and I dont use a proxy-protected internet

Try to add this
allprojects {
repositories {
jcenter()
maven {
url "https://maven.google.com"
}
}}
To your build.gradle and then make a Clean project also Invalidate Cache & Restart from file options should work.

Why I can not add my project dependencies?

When I start a new project, I see the following errors about my dependencies.
Actually, I'm using a VPN but I don't know what's the problem?!
And I didn't have this problem before, but now see that since updating my Android Studio, and I should say I searched about this problem a lot but didn't find any solution
Unable to resolve dependency for ':app#debug/compileClasspath': Could not resolve com.google.android.gms:play-services-maps:16.0.0.
Open File
Show Details
Unable to resolve dependency for ':app#debugAndroidTest/compileClasspath': Could not resolve com.android.support.test:runner:1.0.2.
Open File
Show Details
Unable to resolve dependency for ':app#debugAndroidTest/compileClasspath': Could not resolve com.android.support.test.espresso:espresso-core:3.0.2.
Open File
Show Details
Unable to resolve dependency for ':app#debugAndroidTest/compileClasspath': Could not resolve com.google.android.gms:play-services-maps:16.0.0.
Open File
Show Details
Unable to resolve dependency for ':app#debugUnitTest/compileClasspath': Could not resolve com.google.android.gms:play-services-maps:16.0.0.
Open File
Show Details
Unable to resolve dependency for ':app#release/compileClasspath': Could not resolve com.google.android.gms:play-services-maps:16.0.0.
Open File
Show Details
Unable to resolve dependency for ':app#releaseUnitTest/compileClasspath': Could not resolve com.google.android.gms:play-services-maps:16.0.0.
Open File
Show Details
build.gradle (Module:app):
apply plugin: 'com.android.application'
android {
compileSdkVersion 28
defaultConfig {
applicationId "com.example.pasargad.test_map"
minSdkVersion 19
targetSdkVersion 28
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:28.0.0'
implementation 'com.google.android.gms:play-services-maps:16.0.0'
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'
}
build.gradle (Project:...):
// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
repositories {
google()
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.1.4'
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}
allprojects {
repositories {
google()
jcenter()
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}

First make sure that you have disabled the gradle offline work like the image below.
Now Connect Pc with the internet. Then Sync your Project Again. It should solve your problem.

make sure that android studio is not in offline mode and re sync with internet connection and if all of those do not work then
1) go to android studio folder on file explorer or something and go to gradle and then look at your gradle file (means version for example mine is gradle-4.6-all and then delete it)
2)go to gradler offilce website and download the same gradle version
gradle official site (for example gradle v4.6)
3)unzip it and paste there where you had been deleted
4)Re sync with internet connection

I found my answer. The problem was because of the proxy info in "gradle.properties" file, I deleted all of the lines about proxy (host, password, etc) and synced the project again

Retrofit 2.4.0 with Gradle plugin 3.1.2

I have a very simple question. I'm an Android Developer returning back to development after a 6 months break and as usual everything has changed apparently. Here is my question:
Start a new Android project on Android Studio 3.1.2
Default Gradle plugin is 3.1.2
Added retrofit2 dependency to app's build.gradle
implementation 'com.squareup.retrofit2:retrofit:2.4.0'
Started gradle sync
Unable to resolve dependency for ':app#debug/compileClasspath': Could
not resolve com.squareup.retrofit2:retrofit:2.4.0. Open File Show
Details
Unable to resolve dependency for
':app#debugAndroidTest/compileClasspath': Could not resolve
com.squareup.retrofit2:retrofit:2.4.0. Open File Show Details
Unable to resolve dependency for
':app#debugUnitTest/compileClasspath': Could not resolve
com.squareup.retrofit2:retrofit:2.4.0. Open File Show Details
Unable to resolve dependency for ':app#release/compileClasspath':
Could not resolve com.squareup.retrofit2:retrofit:2.4.0. Open File
Show Details
Unable to resolve dependency for
':app#releaseUnitTest/compileClasspath': Could not resolve
com.squareup.retrofit2:retrofit:2.4.0. Open File Show Details
I read the whole article about Gradle plugin 3 migration. It is no help.
Project build.gradle
// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
repositories {
google()
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.1.2'
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}
allprojects {
repositories {
google()
jcenter()
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}
app level build.gradle
apply plugin: 'com.android.application'
android {
compileSdkVersion 27
buildToolsVersion "27.0.3"
defaultConfig {
applicationId "com.xyz.xyz"
minSdkVersion 15
targetSdkVersion 27
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:27.1.1'
implementation 'com.android.support.constraint:constraint-layout:1.1.0'
implementation 'com.squareup.retrofit2:retrofit:2.4.0'
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'
}

if your PC is running on some proxy please add proxy in android studio or check your internet connection.
For Proxy follow below steps:
File -> Settings -> Appearence & Behaviour -> System Setting -> HTTP Proxy
add your Proxy
Otherwise check your internet connection

I run your code run with no errors. Try to Invalidate Caches/Restart from: File -> Invalidate Caches/Restart

what worked me is to trying to add it through the project structure dependency window
follow these steps :
1- File -> Project structure -> depencies
click apply then try to sync again and it worked fine for me.

How to remove all dependencies on android studio?

I have no internet connection on my machine (because of some reasons) and i want to use Android studio(3) on it with no dependency to the internet.
I Created a very simple (default) App but get lots of errors, I changed the gradle to the local and remove/set offline work option but nothing worked.
Errors:
Error:Unable to resolve dependency for ':app#debug/compileClasspath': Could
not resolve com.android.support:appcompat-v7:26.+.
Open File<br><a
href="Unable to resolve dependency for
':app#debug/compileClasspath': Could not resolve
com.android.support:appcompat-v7:26.+.">Show Details</a>
Error:Unable to resolve dependency for
':app#debugUnitTest/compileClasspath': Could not resolve
com.android.support:appcompat-v7:26.+.
Open File<br><a
href="Unable to resolve dependency for
':app#debugUnitTest/compileClasspath': Could not resolve
com.android.support:appcompat-v7:26.+.">Show Details</a>
Error:Unable to resolve dependency for ':app#release/compileClasspath':
Could not resolve com.android.support:appcompat-v7:26.+.
Open File<br><a
href="Unable to resolve dependency for
':app#release/compileClasspath': Could not resolve
com.android.support:appcompat-v7:26.+.">Show Details</a>
Error:Unable to resolve dependency for
':app#releaseUnitTest/compileClasspath': Could not resolve
com.android.support:appcompat-v7:26.+.
Open File<br><a
href="Unable to resolve dependency for
':app#releaseUnitTest/compileClasspath': Could not resolve
com.android.support:appcompat-v7:26.+.">Show Details</a>
build.gradle(app):
apply plugin: 'com.android.application'
android {
compileSdkVersion 26
defaultConfig {
applicationId "com.example.administrator.myapplication"
minSdkVersion 23
targetSdkVersion 26
versionCode 1
versionName "1.0"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'),
'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:26.+'
implementation 'com.android.support.constraint:constraint-layout:1.0.2'
}
build.gradle(project):
buildscript {
repositories {
google()
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.0.0'
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}
allprojects {
repositories {
google()
jcenter()
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}

For the first time you need to be connected to the internet so that all your dependencies could be fetched. Once that's done, you no longer need the internet.
But if you try building again, Android Studio (gradle) will still try to connect to internet to refresh the dependencies. If you can't be online then you need to tell Android Studio (i.e, gradle) to work offline.
Go to Android Studio's Preferences -> Build, Execution, Deployment -> Offline Work
Turn this option on and gradle will start to work offline.
Note: com.android.support:appcompat-v7:26.+. won't really work here. You need to mention the specific artifact id and not +.