關於Android屏幕橫豎之間的切換，研究心得。

原創

RockCode_li

2020-02-21 05:35

之前有人提到過Android屏幕橫豎之間的切換，大部分都說是在爲設置configchanges之前，豎屏切換橫屏Activity的生命週期是：onSaveInstanceState-->onPause-->onStop-->

onDestroy-->onCreate-->onStart-->onRestoreInstanceState-->onResume-->

當橫屏再切換成豎屏時：會調用兩次上述過程：

onSaveInstanceState-->
onPause-->
onStop-->
onDestroy-->
onCreate-->
onStart-->
onRestoreInstanceState-->
onResume-->
onSaveInstanceState-->
onPause-->
onStop-->
onDestroy-->
onCreate-->
onStart-->
onRestoreInstanceState-->
onResume-->

等等之類的。我就不多說了。

古畫說的好，jue知此事要躬行，so：

下面是我自己的研究結果：

代碼先呈上：

MainActivity.java

package com.example.liferecycletest;

import android.app.Activity;
import android.content.res.Configuration;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.TextView;

public class MainActivity extends Activity {
	public static final String TAG = "LifeRecycleTest";

	TextView tv = null;
	TextView tv_ = null;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		showLog("onCreate");
		tv = (TextView) findViewById(R.id.hello);
		tv_ = (TextView) findViewById(R.id.hello_);
		findViewById(R.id.btn).setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View arg0) {
				// TODO Auto-generated method stub
				tv.setText("Just Changed");
				tv_.setText("Just Changed");
			}

		});
	}

	public void showLog(String info) {
		Log.e(TAG, info);
	}

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

	@Override
	protected void onPause() {
		// TODO Auto-generated method stub
		super.onPause();
		showLog("onPause");
	}

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

	@Override
	protected void onRestoreInstanceState(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onRestoreInstanceState(savedInstanceState);
		if (savedInstanceState != null) {
			tv.setText(savedInstanceState.getString("text"));
		}
		showLog("onResoreInstanceState");
	}

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

	@Override
	protected void onSaveInstanceState(Bundle outState) {
		// TODO Auto-generated method stub
		super.onSaveInstanceState(outState);
		showLog("onSaceInstanceState");
		outState.putString("text", "Just Change");
	}

	@Override
	public void onConfigurationChanged(Configuration newConfig) {
		// TODO Auto-generated method stub
		super.onConfigurationChanged(newConfig);
		showLog("onConfigurationChanged");
	}

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

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

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.liferecycletest"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="21" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

現在很情況說下：

A.在沒有設置configchanges的情況下：

豎——>橫屏幕的切換Log：