How to use Data Binding and Kotlin in Android Stud

问题:

I just started to use Android Studio 3.0.0, but every time I try to build my project I get this error:

Error:Circular dependency between the following tasks:
:app:compileDebugKotlin
+--- :app:dataBindingExportBuildInfoDebug
|    \--- :app:compileDebugKotlin (*)
\--- :app:kaptDebugKotlin
     \--- :app:dataBindingExportBuildInfoDebug (*)
(*) - details omitted (listed previously)

I am using

kapt "com.android.databinding:compiler:2.2.0"

Before I was using

androidProcessor "com.android.databinding:compiler:2.2.0"

And it was working just fine... What I am doing wrong??

Thanks!

回答1:

It seems that you need 3 gradle entries in the app .gradle at module level to add data binding

1. apply plugin: 'kotlin-kapt'
2. android { ... dataBinding { enabled = true } }
3. dependencies { ...... kapt "com.android.databinding:compiler:$compiler_version" }

Notice that I made compiler version a variable in the project level build gradle so it can be managed from a single place

default was: ext.kotlin_version = '1.1.3-2'

I added with bracket syntax:

ext{
    kotlin_version = '1.1.3-2'
    compiler_version = '3.0.0-beta6'
}

回答2:

UPD: This was fixed for Android Gradle plugin 3.0.0-alpha3, in yout project root build.gradle, change the buildscript dependencies to use

classpath 'com.android.tools.build:gradle:3.0.0-alpha3'

---

This is actually a bug in the Kotlin Gradle plugin 1.1.2-4 inter-operation with the Android Gradle plugin 3.0.0-alpha1, caused by how the inputs and outputs of the tasks are set (and thus how the tasks are connected with the depends-on relation).

Thanks @VyacheslavGerasimov for creating the issue KT-17936.

---

As a temporary workaround, you can try to revert to Kotlin Gradle plugin 1.1.2-2 and disable incremental compilation:

In your project's root build.gradle, change the version of the Kotlin Gradle plugin:

buildscript {
    ...
    dependencies {
        ...
        classpath 'org.jetbrains.kotlin:kotlin-gradle-plugin:1.1.2-2'
    }
}

Add local.properties to the project root, with the following line:

kotlin.incremental=false

^{It is a known issue that the Kotlin Gradle plugin 1.1.2-2 and below crashes with the newest AGP versions, and disabling incremental compilation seems to fix that crash.}

回答3:

For those still looking for a proper solution, Google has already fixed this issue in Android Studio 3.0 Canary 3 build.

Friday, June 2, 2017

We have just released Android Studio 3.0 Canary 3 to the Canary and Dev Channels. The Android Gradle Plugin 3.0.0-alpha3 was also released through maven.google.com. This release has fixes to Gradle, Kotlin, and many other fixes. We continue to fix bugs in all areas of Studio 3.0 as we stabilize our features, so please continue to pass on feedback.

Working gradle configuration:

build.gradle (project)

buildscript {
    ext.kotlin_version = '1.1.2-4'
    repositories {
        jcenter()
        maven {
            url 'https://maven.google.com'
        }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.0-alpha3'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}

build.gradle (module)

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-kapt'


android {
    dataBinding.enabled = true
}
dependencies {
    kapt "com.android.databinding:compiler:3.0.0-alpha3"
}

回答4:

I have recenly write Blog for Data Binding android with Kotlin here

Use Classpath

classpath 'com.android.tools.build:gradle:3.0.0-beta2'

Dependency

apply plugin: 'kotlin-android'

apply plugin: 'kotlin-android-extensions'

apply plugin: 'kotlin-kapt'

android {
    ...
    dataBinding {
        enabled = true
    }
}

dependencies {
    ......
    kapt 'com.android.databinding:compiler:2.3.1'
}

for more detail check out this post