kotlin activity 生命周期

第一个页面 也是启动页

class FirstActivity : AppCompatActivity() {

    lateinit var tvNext: TextView


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_first)

        Log.d("lxf", "FirstActivity onCreate")

        tvNext = findViewById(R.id.textView)
        tvNext.setOnClickListener {

            val intent = Intent(this, NextActivity::class.java)
            startActivity(intent)
        }
    }

    override fun onStart() {
        super.onStart()
        Log.d("lxf", "FirstActivity onStart")

    }


    override fun onResume() {
        super.onResume()
        Log.d("lxf", "FirstActivity onResume")

    }


    override fun onPause() {
        super.onPause()
        Log.d("lxf", "FirstActivity onPause")

    }


    override fun onStop() {
        super.onStop()
        Log.d("lxf", "FirstActivity onStop")

    }

    override fun onRestart() {
        super.onRestart()
        Log.d("lxf", "FirstActivity onRestart")

    }


    override fun onDestroy() {
        super.onDestroy()
        Log.d("lxf", "FirstActivity onDestroy")

    }

}

第二个页面

class NextActivity : AppCompatActivity() , View.OnClickListener{


    lateinit var tvBack: TextView

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_next)
        Log.d("lxf", "NextActivity onCreate")

        tvBack = findViewById(R.id.tv_back);
        tvBack.setOnClickListener(this)
    }



    override fun onStart() {
        super.onStart()
        Log.d("lxf", "NextActivity onStart")

    }


    override fun onResume() {
        super.onResume()
        Log.d("lxf", "NextActivity onResume")

    }


    override fun onPause() {
        super.onPause()
        Log.d("lxf", "NextActivity onPause")

    }


    override fun onStop() {
        super.onStop()
        Log.d("lxf", "NextActivity onStop")

    }

    override fun onRestart() {
        super.onRestart()
        Log.d("lxf", "NextActivity onRestart")

    }


    override fun onDestroy() {
        super.onDestroy()
        Log.d("lxf", "NextActivity onDestroy")

    }

    override fun onClick(v: View?) {
        v?.apply {

            when (v.id) {
                R.id.tv_back -> {
                    finish()
                }

            }
        }

    }


}

查看 Log 输出

运行app

D/lxf: FirstActivity onCreate
D/lxf: FirstActivity onStart
D/lxf: FirstActivity onResume

清空 log 点击下一页

D/lxf: FirstActivity onPause
D/lxf: NextActivity onCreate
D/lxf: NextActivity onStart
D/lxf: NextActivity onResume
D/lxf: FirstActivity onStop

清空 log 点击返回

D/lxf: NextActivity onPause
D/lxf: FirstActivity onRestart
D/lxf: FirstActivity onStart
D/lxf: FirstActivity onResume
D/lxf: NextActivity onStop
D/lxf: NextActivity onDestroy

清空 log 通过Home键退回到手机桌面

D/lxf: FirstActivity onPause
D/lxf: FirstActivity onStop

清空 log 再次打开App

D/lxf: FirstActivity onRestart
D/lxf: FirstActivity onStart
D/lxf: FirstActivity onResume

清空 log 通过 返回键 退回到手机桌面

D/lxf: FirstActivity onPause
D/lxf: FirstActivity onStop
D/lxf: FirstActivity onDestroy

清空 log 再次打开App

D/lxf: FirstActivity onCreate
D/lxf: FirstActivity onStart
D/lxf: FirstActivity onResume