Intent回传数据与Activity生命周期

最新推荐文章于 2022-10-21 22:32:41 发布

原创最新推荐文章于 2022-10-21 22:32:41 发布 · 657 阅读

CC 4.0 BY-SA版权

本文详细介绍了Android中Activity的生命周期，包括从启动到销毁的各个阶段方法：onCreate、onStart、onResume、onPause、onStop、onDestroy等，并演示了如何通过这些方法实现界面跳转、数据保存与恢复等功能。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

package com.example.activitytest;

import android.os.Bundle;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Intent;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

/**

主类

public class MainActivity extends Activity {
   private EditText et_name, et_pwd;
   private Button jump;

   @Override
   protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_main);
       init();
   }

   private void init() {
       // 通过id找对象
       et_name = (EditText) super.findViewById(R.id.et_name);
       et_pwd = (EditText) super.findViewById(R.id.et_pwd);
       jump = (Button) super.findViewById(R.id.jump);
       jump.setOnClickListener(new OnClickListener() {

           @Override
           public void onClick(View v) {
               // 判断输入的用户名和密码是否一致
               if (et_name.getText().toString().equals("admin")
                       && et_pwd.getText().toString().equals("123")) {
                   Toast.makeText(MainActivity.this, "输入成功",
                           Toast.LENGTH_SHORT).show();
                   Intent intent = new Intent(MainActivity.this,
                           TiaoActivity.class);
                   intent.putExtra("name", et_name.getText().toString());
                   intent.putExtra("pwd", et_pwd.getText().toString());
                   // 开启意图
                   startActivityForResult(intent, 1);
               } else {
                   Toast.makeText(MainActivity.this, "输入错误，请重新输入",
                           Toast.LENGTH_SHORT).show();
               }
           }
       });
   }

   @Override
   protected void onActivityResult(int requestCode, int resultCode, Intent data) {
       // TODO Auto-generated method stub
       super.onActivityResult(requestCode, resultCode, data);
       if (requestCode == 1 && resultCode == 2) {
           String xiu_name = data.getStringExtra("xiu_name");
           String xiu_pwd = data.getStringExtra("xiu_pwd");
           et_name.setText(xiu_name);
           et_pwd.setText(xiu_pwd);
       }
   }

   @Override
   protected void onSaveInstanceState(Bundle outState) {
       // TODO Auto-generated method stub
       super.onSaveInstanceState(outState);
       outState.putString("activity_bundle", "测试数据");
       Log.e("TAG", "onSaveInstanceState.........");
   }

   @Override
   protected void onDestroy() {
       // TODO Auto-generated method stub
       super.onDestroy();
       Log.e("TAG", "onDestroy.........");
   }

   @Override
   protected void onPause() {
       // 持久化操作
       super.onPause();
       Log.e("TAG", "onPause.........");
   }

   @Override
   protected void onRestart() {
       // TODO Auto-generated method stub
       super.onRestart();
       Log.e("TAG", "onRestart.........");
   }

   @SuppressLint("NewApi")
   @Override
   protected void onRestoreInstanceState(Bundle savedInstanceState) {
       // TODO Auto-generated method stub
       super.onRestoreInstanceState(savedInstanceState);
       Log.e("TAG", "onRestoreInstanceState.........");
       Log.e("TAG",
               "onRestoreInstanceState----->"
                       + savedInstanceState.getString("activity_bundle",
                               "erroy"));
   }

   @Override
   protected void onResume() {
       // TODO Auto-generated method stub
       super.onResume();
       Log.e("TAG", "onResume.........");
   }

   @Override
   protected void onStart() {
       // TODO Auto-generated method stub
       super.onStart();
       Log.e("TAG", "onStart.........");
   }

   @Override
   protected void onStop() {
       // TODO Auto-generated method stub
       super.onStop();
       Log.e("TAG", "onStop..........");
   }

   @Override
   public boolean onCreateOptionsMenu(Menu menu) {
       // Inflate the menu; this adds items to the action bar if it is present.
       getMenuInflater().inflate(R.menu.activity_main, menu);
       return true;
   }

}

跳转的目的Activity

package com.example.activitytest;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class TiaoActivity extends Activity {
   private EditText et_name, et_pwd;
   private Button back;
   private Intent intent;

   @Override
   protected void onCreate(Bundle savedInstanceState) {
       // TODO Auto-generated method stub
       super.onCreate(savedInstanceState);
       setContentView(R.layout.back);
       et_name = (EditText) super.findViewById(R.id.b_et_name);
       et_pwd = (EditText) super.findViewById(R.id.b_et_pwd);
       back = (Button) super.findViewById(R.id.back);
       // 接收传来的意图
       intent = getIntent();

       String name1 = intent.getStringExtra("name");
       String pwd1 = intent.getStringExtra("pwd");

       et_name.setText(name1);
       et_pwd.setText(pwd1);
       // 给返回按钮加监听
       back.setOnClickListener(new OnClickListener() {

           @Override
           public void onClick(View v) {

               Intent inte = new Intent();
               inte.setClass(TiaoActivity.this, MainActivity.class);
               // 对传来的数据进行修改
               inte.putExtra("xiu_name", et_name.getText().toString());
               inte.putExtra("xiu_pwd", et_pwd.getText().toString());
               Toast.makeText(TiaoActivity.this, "数据修改成功", Toast.LENGTH_SHORT)
                       .show();
               setResult(2, inte);
               finish();
           }
       });
   }
}