My R library is red, but I can normally create and run the application

Question

I am using compile project(':pickphotos') to include a library called pickphotos.

R in pickphotos is red, although I have me.crosswall.photo.pick.RI I can normally create and run the application.

When I use Alt + Enter, it shows some solution:

When I use Move 'R' in pickphotos, it shows some R:

But if I take me.crosswall.photo.pick.R, I will get a repeated R error in my next build.

Below is the pickphotos assembly:

 apply plugin: 'com.android.library' android { compileSdkVersion 23 buildToolsVersion '23.0.2' compileOptions { sourceCompatibility JavaVersion.VERSION_1_7 targetCompatibility JavaVersion.VERSION_1_7 } defaultConfig { minSdkVersion 14 targetSdkVersion 23 versionCode 1 versionName "1.0" } buildTypes { release { minifyEnabled false proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' } } sourceSets { main { manifest.srcFile 'AndroidManifest.xml' java.srcDirs = ['src'] res.srcDirs = ['res'] } } } dependencies { } 

I can also find it app / build / generated / source / r:

Android Studio does not have a Mark object:

Answer 1

I finally found this.

Just create a project.

R is created when a project is created.

I think that when we launch a project or create a project, Android Studio does not do the project for some reason.

Answer 2

Going to assembly> Reconstructing a project and / or a Clean project seems to be goto's first attempt to fix any errors related to brief errors. It’s better to do this, and then spend 45 minutes looking at the code, trying to figure out what is wrong when the answer is “nothing” ...