android系统四大组件之Activity
作者:互联网
Activity的生命周期
我们通过编写测试程序来分析其生命周期。
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.Button;
public class MainActivity extends AppCompatActivity {
private Button button;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d("MainActivity","onCreate()被调用");
}
@Override
protected void onStart() {
super.onStart();
Log.d("MainActivity","onStart()被调用");
}
@Override
protected void onResume() {
super.onResume();
Log.d("MainActivity","onResume()被调用");
}
@Override
protected void onPause() {
super.onPause();
Log.d("MainActivity","onPause()被调用");
}
@Override
protected void onStop() {
super.onStop();
Log.d("MainActivity","onStop()被调用");
}
@Override
protected void onDestroy() {
super.onDestroy();
Log.d("MainActivity","onDestroy()被调用");
}
@Override
protected void onRestart() {
super.onRestart();
Log.d("MainActivity","onRestart()被调用");
}
}
当我们一开始启动app时,会调用依次调用OnCreate()->OnStart()->OnResume()
当我们将app移动到后台时,会依次调用OnPause()->OnStop()
当我们再次将app从后台点击到前台屏幕上是,会依次调用OnRestart()->OnStart()->OnResume()
当我们将app退出时,会依次调用OnPause()->OnStop()->OnDestroy()
activity启动方式
标签:调用,Log,void,MainActivity,Override,Activity,组件,android,super 来源: https://www.cnblogs.com/revercc/p/16133030.html