Kotlin初体验

项目环境 android studio 2.2.2

首先安装 Kotlin插件

然后重新启动 Android Studio

module build 文件 在buildscript级下

    dependencies {
    classpath 'com.android.tools.build:gradle:2.2.2'
    classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    classpath "org.jetbrains.kotlin:kotlin-android-extensions:$kotlin_version"
    // NOTE: Do not place your application dependencies here; they belong
    // in the individual module build.gradle files
}

app的 build文件 跟android同级

buildscript{
    ext.kotlin_version = '1.0.1-2'
    repositories{
        jcenter()
    }
    dependencies {
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
        classpath "org.jetbrains.kotlin:kotlin-android-extensions:$kotlin_version"
    }
}

android下

sourceSets {
        main.java.srcDirs += 'src/main/kotlin'
    }

dependencies 引入包

compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"

添加的有

注意的是要在 module 的build文件下添加 要不会报Error:(6, 8) Unresolved reference: kotlinx 这个错误

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

buildscript{
    ext.kotlin_version = '1.0.1-2'
    repositories{
        jcenter()
    }
    dependencies {
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
        classpath "org.jetbrains.kotlin:kotlin-android-extensions:$kotlin_version"
    }
}

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.2"
    defaultConfig {
        applicationId "com.project.kotlintext"
        minSdkVersion 15
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    sourceSets {
        main.java.srcDirs += 'src/main/kotlin'
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:25.3.1'
    testCompile 'junit:junit:4.12'
}

转换代码 选中需要转换的Java文件, 如MainActivity.java,
使用Ctrl+Shift+A, 启动Action, 输入Convert Kotlin, 找到命令, 即可转换

点击后就会转换
然后转换成功就会有这样的图标

然后在MainActivity.kt

import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        name_tv.text="hello world!";
    }
}

然后点击运行查看是否成功

要是觉得我写的配置看不懂 我写了个小例子 可以直接看配置文件
https://github.com/shaomiao/KotlinText