Android Kotlin(二)

跳转activity

public fun goConstrantLayout(view:View){
        //var intent:Intent = Intent(this,Main2Activity().javaClass)
        //startActivity(intent)
    var intent:Intent = Intent(this,Main2Activity::class.java)
    startActivity(intent)
}

两种写法都行

获取多个view遍历

    class Main2Activity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main2)
       setListeners()
    }
    
    //Kotlin 后去view遍历点击，id就是view
    private fun setListeners() {
        var clickableViews:List = listOf(
            box_one_text,box_two_text,box_three_text,box_four_text,box_five_text
        )

        for(item in clickableViews){
            item.setOnClickListener{makeColors(it)}
        }

    }

    private fun makeColors(view:View) {
        when(view.id){
            R.id.box_one_text->view.setBackgroundColor(Color.DKGRAY)
            R.id.box_two_text->view.setBackgroundColor(Color.GRAY)
            R.id.box_three_text->view.setBackgroundColor(Color.GREEN)
            R.id.box_four_text->view.setBackgroundColor(Color.YELLOW)
            R.id.box_five_text->view.setBackgroundColor(Color.RED)
            else
                ->view.setBackgroundColor(Color.GRAY)

        }
    }
}