Android Activity的生命周期 意图(Intent)

package cn.lwx.activitycreate;import androidx.appcompat.app.AppCompatActivity;import android.os.Bundle;import android.util.Log;public class MainActivity extends AppCompatActivity {@Override //当页面创建的时候执行protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_example);Log.i("MainActivity","调用onCreate()方法");}@Override //当页面可见执行protected void onStart() {super.onStart();Log.i("MainActivity","调用onStart()方法");}@Override //当Activity获取焦点开始与用户交互时protected void onResume() {super.onResume();Log.i("MainActivity","调用onResume()方法");}@Override //当Activity被覆盖（失去焦点,用户不可进行交互）protected void onPause() {super.onPause();Log.i("MainActivity","调用onPause()方法");}@Override //当页面不可见的时候执行protected void onStop() {super.onStop();Log.i("MainActivity","调用onStop()方法");}@Override //当页面销毁时执行protected void onDestroy() {super.onDestroy();Log.i("MainActivity","调用onDestroy()方法");}@Override //当页面重新启动时执行protected void onRestart() {super.onRestart();Log.i("MainActivity","调用onRestart()方法");}}

package cn.lwx.activitycreate;import androidx.appcompat.app.AppCompatActivity;import android.content.Intent;import android.os.Bundle;import android.util.Log;public class MainActivity extends AppCompatActivity {@Override //当页面创建的时候执行protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_example);Log.i("MainActivity","调用onCreate()方法");// 1、通过显示意图开启ActivityIntent intent = new Intent(this, ActivityExample.class);startActivity(intent);// 2、通过隐式意图开启Activity 清单文件Intent intent2 = new Intent();intent.setAction("com.lwx.main2");intent.addCategory("android.intent.category.DEFAULT");startActivity(intent);}