Android开发 ---Activity的7种运行状态

 Android开发 ---Activity的7种运行状态

创建 --> 启动 --> 运行 -->  暂停 --> 停止 --> 销毁

重启

操作图解：

1、MainActivity.java

package com.example.android_activity;

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

public class MainActivity extends Activity {

    //创建Activity时调用，一个生命周期只有一次执行
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //绑定当前窗体的布局文件
        setContentView(R.layout.activity_main);
        Toast.makeText(this,"Activity创建时调用onCreate()方法",Toast.LENGTH_LONG).show();
    }
    //去到注册窗体
    public void toRegister(View view){
        Intent intent=new Intent(this,RegisterActivity.class);
        startActivity(intent);
    }
    //Activity启动时调用
    @Override
    protected void onStart() {
        super.onStart();
        Toast.makeText(this,"Activity被启动时调用onStart()方法",Toast.LENGTH_LONG).show();
    }

    //Activity进入运行状态时调用[进入激活必经之路]
    @Override
    protected void onResume() {
        super.onResume();
        Toast.makeText(this,"Activity进入运行状态时调用onResume方法",Toast.LENGTH_LONG).show();
    }

    //Activity从Stop状态重启时调用
    @Override
    protected void onRestart() {
        super.onRestart();
        Toast.makeText(this,"Activity从停止状态重启时调用onRestart()方法",Toast.LENGTH_LONG).show();
    }

    //Activity进入暂停状态[退出激活必经之路]
    @Override
    protected void onPause() {
        super.onPause();
        Toast.makeText(this,"Activity进入暂停状态时调用onPause()方法",Toast.LENGTH_LONG).show();
    }

    //进入停止状态时调用
    @Override
    protected void onStop() {
        super.onStop();
        Toast.makeText(this,"Activity进入停止状态时调用onStop()方法",Toast.LENGTH_LONG).show();
    }

    //销毁Activity实例,一个生命周期只有一次执行
    @Override
    protected void onDestroy() {
        super.onDestroy();
        Toast.makeText(this,"Activity被销毁时调用onDestroy()方法",Toast.LENGTH_LONG).show();
    }
}

2、RegisterActivity.java

package com.example.android_activity;

import android.app.Activity;
import android.os.Bundle;

public class RegisterActivity extends Activity {

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

3、activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    >
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="30sp"
        android:onClick="toRegister"
        android:text="用户注册"
        />
</LinearLayout>

效果图：