AndroidStudio kotlin配置

安装插件

File -> Settings -> Plugins -> Browse repositories -> 搜索 kotlin 

gradle添加依赖

Module的build.gradle

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

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.2"
    defaultConfig {
        applicationId "com.lxs.kotlinconfig"
        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'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    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'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    testCompile 'junit:junit:4.12'

    compile "org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"
    compile "org.jetbrains.kotlin:kotlin-reflect:$kotlin_version"
}

repositories {
    maven {url 'http://maven.aliyun.com/nexus/content/groups/public/'}
}

Project的build.gradle

buildscript {
    ext.kotlin_version = '1.1.2-4'
    repositories {
        maven {url 'http://maven.aliyun.com/nexus/content/groups/public/'}
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.2'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        maven {url 'http://maven.aliyun.com/nexus/content/groups/public/'}
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

kotlin.incremental=true增量编译的机制，可以加快编译速度 项目根目录的gradle.properties里配置

 

把Java代码转换成kotlin代码

Code -> Convert Java File to Kotlin File

快捷键 ctrl+alt+shift+k

或者ctrl+shift+A　　输入Convert Java File to Kotlin File

 

Kotlin提供以下代表数字的内置类型
类型      位宽
Double      64
Float       32
Long        64
Int         32
Short       16
Byte        8

Kotlin支持二进制(0b开头)十六进制(ox开头)但不支持八进制。

Kotlin支持数字下划线
val oneMillion = 1_000_000
val creditCardNumber = 1234_5678_9012_3456L
val socialSecurityNumber = 999_99_9999L
val hexBytes = 0xFF_EC_DE_5E
val bytes = 0b11010010_01101001_10010100_10010010

Kotlin中按位操作
shl(bits)   左移运算符（Java <<）
shr(bits)   右移运算符（Java >>）
ushr(bits)  无符号右移，忽略符号位，空位都以0补齐（Java >>>）
and(bits)   按位和
or(bits)    按位或
xor(bits)   按位xor
inv()       逐位倒置

 Kotlin中自带非空检查如要为空val s:String? = null;

 Kotlin中支持的转义字符\t，\b，\n，\r，\'，\"，\\和\$。要编码任何其他字符，请使用Unicode转义序列语法：'\uFF00'

 Kotlin中引入类对象this@类名

Kotlin中运算符重载
一元前缀运算符
+a	a.unaryPlus()
-a	a.unaryMinus()
!a	a.not()

递增和递减
a++	a.inc()
a--	a.dec()

算术运算符
a + b	a.plus(b)
a - b	a.minus(b)
a * b	a.times(b)
a / b	a.div(b)
a % b	a.rem(b)，a.mod(b)（已弃用）
a..b	a.rangeTo(b)
a in b	b.contains(a)
a !in b	!b.contains(a)

索引访问操作符 方括号转换为调用get和set适当数量的参数。
a[i]	a.get(i)
a[i, j]	a.get(i, j)
a[i_1, ..., i_n]	a.get(i_1, ..., i_n)
a[i] = b	a.set(i, b)
a[i, j] = b	a.set(i, j, b)
a[i_1, ..., i_n] = b	a.set(i_1, ..., i_n, b)

自身运算
a += b	a.plusAssign(b)
a -= b	a.minusAssign(b)
a *= b	a.timesAssign(b)
a /= b	a.divAssign(b)
a %= b	a.modAssign(b)

等于非等于
a == b	a?.equals(b) ?: (b === null)
a != b	!(a?.equals(b) ?: (b === null))

 比较运算符
a > b	a.compareTo(b) > 0
a < b	a.compareTo(b) < 0
a >= b	a.compareTo(b) >= 0
a <= b	a.compareTo(b) <= 0

集合类
val items = listOf("item1", "item2", "item3")
val items:MutableList<String> = mutableListOf("item1", "item2", "item3");
遍历
for (item in items) {
    println(item)
}
for (index in items.indices) {
    println("item at $index is ${items[index]}")
}
val set = setOf("item1", "item2", "item3");
val set:MutableSet<String> = mutableSetOf("item1", "item2", "item3");
val map = mapOf("a" to 1, "b" to 2, "c" to 3)
val map = mutableMapOf<String,Int>("a" to 1, "b" to 2, "c" to 3)
for ((k, v) in map) {
    println("$k -> $v")
}

for (i in 1..4 step 2) 正序从1到4步长为2 step无时默认为1
for (i in 4 downTo 1 step 2) 倒序从4到1步长为2
for (i in 1 until 10)不包含上限

println控制台输出

 

结合DataBinding 使用时需添加如下

kapt {
　　generateStubs = true
}

dependencies {

　　kapt "com.android.databinding:compiler:2.3.0"
}

https://github.com/j2eemail/KotlinConfig