Kotlin plug-ins kotlin Android extensions

plugins {
    id 'com.android.application'
    id 'kotlin-android'
    id 'kotlin-android-extensions'
}

Now the plug-in will not automatically import , Then we are build.gradle Add , Code above

This plug-in will be based on the control defined in the layout file id Automatically generate a variable with the same name , We can do it in Activity Use this variable directly in , Instead of calling findViewById() Method

Pictured above , I have a button id by btn, Just use it directly