Android 横竖屏和构造问题

发布时间：2021-11-20 14:24:31 所属栏目：PHP教程来源：互联网

导读：在这里我做了一个小test,之前看过关于这方面的东西，到后来我才真正的遇到项目的时候，不得已才要去真正的熟悉里面的流程。这里我贴测试源码： TestActivity.java package cn.com.hrmdemo; import Android.app.Activity; import android.content.res.Config

在这里我做了一个小test,之前看过关于这方面的东西，到后来我才真正的遇到项目的时候，不得已才要去真正的熟悉里面的流程。

这里我贴测试源码：

TestActivity.java

package cn.com.hrmdemo;

import Android.app.Activity;
import android.content.res.Configuration;
import android.os.Bundle;
import android.widget.Toast;

public class TestActivity extends Activity {

@Override
protected void onCreate(Bundle arg0) {
System.out.println("------ TestActivity onCreate------");
Toast.makeText(this, "onCreate。。。", Toast.LENGTH_SHORT).show();
super.onCreate(arg0);
setContentView(R.layout.test_linearlayout);
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
System.out.println("------ TestActivity onRestoreInstanceState------");
Toast.makeText(this, "onRestoreInstanceState。。。", Toast.LENGTH_SHORT).show();
// TODO Auto-generated method stub
super.onRestoreInstanceState(savedInstanceState);
}

@Override
protected void onStart() {
System.out.println("------ TestActivity onStart------");
Toast.makeText(this, "onStart。。。", Toast.LENGTH_SHORT).show();
// TODO Auto-generated method stub
super.onStart();
}

@Override
protected void onRestart() {
System.out.println("------ TestActivity onRestart------");
Toast.makeText(this, "onRestart。。。", Toast.LENGTH_SHORT).show();
// TODO Auto-generated method stub
super.onRestart();
}

@Override
protected void onResume() {
System.out.println("------ TestActivity onResume------");
Toast.makeText(this, "onResume。。。", Toast.LENGTH_SHORT).show();
// TODO Auto-generated method stub
super.onResume();
}

@Override
protected void onSaveInstanceState(Bundle outState) {
System.out.println("------ TestActivity onSaveInstanceState------");
Toast.makeText(this, "onSaveInstanceState。。。", Toast.LENGTH_SHORT).show();
// TODO Auto-generated method stub
super.onSaveInstanceState(outState);
}

@Override
protected void onPause() {
System.out.println("------ TestActivity onPause------");
Toast.makeText(this, "onPause。。。", Toast.LENGTH_SHORT).show();
// TODO Auto-generated method stub
super.onPause();
}

@Override
protected void onStop() {
System.out.println("------ TestActivity onStop------");
Toast.makeText(this, "onStop。。。", Toast.LENGTH_SHORT).show();
// TODO Auto-generated method stub
super.onStop();
}

@Override
protected void onDestroy() {
System.out.println("------ TestActivity onDestroy------");
Toast.makeText(this, "onDestroy。。。", Toast.LENGTH_SHORT).show();
// TODO Auto-generated method stub
super.onDestroy();
}

@Override
public void onConfigurationChanged(Configuration newConfig) {
System.out.println("------ TestActivity onConfigurationChanged------");
Toast.makeText(this, "屏幕转变了。。。", Toast.LENGTH_SHORT).show();
// TODO Auto-generated method stub
super.onConfigurationChanged(newConfig);
}

}

------------------------------------------------------上面是源码----------------------------------------------------------

下面看看demo的配置和运行的效果是怎样

这个横竖屏的配置主要是在AndroidManiFest.xml，就是Android App 的清单文件：

<activity .....

android:configChanges="想要配置的方式"

>

在你的activity 里面配置你的横竖屏切换方式

1). 什么都不做配置的情况下

a.正常情况下：

07-24 08:43:59.519: I/System.out(18726): ------ TestActivity onCreate------
07-24 08:43:59.609: I/System.out(18726): ------ TestActivity onStart------
07-24 08:43:59.619: I/System.out(18726): ------ TestActivity onResume------

b.切换横屏情况下：

07-24 08:51:01.359: I/System.out(18936): ------ TestActivity onPause------
07-24 08:51:01.379: I/System.out(18936): ------ TestActivity onSaveInstanceState------
07-24 08:51:01.389: I/System.out(18936): ------ TestActivity onStop------
07-24 08:51:01.399: I/System.out(18936): ------ TestActivity onDestroy------
07-24 08:51:01.429: D/memalloc(18936): /dev/pmem: Unmapping buffer base:0x5bb4d000 size:4608000 offset:3072000
07-24 08:51:01.429: D/memalloc(18936): /dev/pmem: Unmapping buffer base:0x5c8c5000 size:16531456 offset:14995456
07-24 08:51:01.449: I/System.out(18936): ------ TestActivity onCreate------
07-24 08:51:01.579: I/System.out(18936): ------ TestActivity onStart------
07-24 08:51:01.579: I/System.out(18936): ------ TestActivity onRestoreInstanceState------
07-24 08:51:01.599: I/System.out(18936): ------ TestActivity onResume------

c.再切换回竖屏的情况下：

07-24 08:51:42.669: I/System.out(18936): ------ TestActivity onPause------
07-24 08:51:42.689: I/System.out(18936): ------ TestActivity onSaveInstanceState------
07-24 08:51:42.699: I/System.out(18936): ------ TestActivity onStop------
07-24 08:51:42.729: I/System.out(18936): ------ TestActivity onDestroy------
07-24 08:51:42.759: D/memalloc(18936): /dev/pmem: Unmapping buffer base:0x5c8c5000 size:4608000 offset:3072000
07-24 08:51:42.759: D/memalloc(18936): /dev/pmem: Unmapping buffer base:0x5cd2a000 size:10797056 offset:9261056
07-24 08:51:42.789: I/System.out(18936): ------ TestActivity onCreate------
07-24 08:51:42.859: I/System.out(18936): ------ TestActivity onStart------
07-24 08:51:42.859: I/System.out(18936): ------ TestActivity onRestoreInstanceState------
07-24 08:51:42.879: I/System.out(18936): ------ TestActivity onResume------

2)配置android:configChanges="orientation|keyboardHidden" （4.0以前）

a.正常情况下：

07-24 08:54:05.059: I/System.out(18936): ------ TestActivity onCreate------
07-24 08:54:05.199: I/System.out(18936): ------ TestActivity onStart------
07-24 08:54:05.219: I/System.out(18936): ------ TestActivity onResume------

b.切换横屏情况下：

07-24 08:54:25.909: I/System.out(18936): ------ TestActivity onPause------
07-24 08:54:25.919: I/System.out(18936): ------ TestActivity onSaveInstanceState------
07-24 08:54:25.929: I/System.out(18936): ------ TestActivity onStop------
07-24 08:54:25.949: I/System.out(18936): ------ TestActivity onDestroy------
07-24 08:54:25.979: D/memalloc(18936): /dev/pmem: Unmapping buffer base:0x5c7c5000 size:19603456 offset:18067456
07-24 08:54:25.979: D/memalloc(18936): /dev/pmem: Unmapping buffer base:0x5da77000 size:4608000 offset:3072000
07-24 08:54:26.019: I/System.out(18936): ------ TestActivity onCreate------
07-24 08:54:26.069: I/System.out(18936): ------ TestActivity onStart------
07-24 08:54:26.079: I/System.out(18936): ------ TestActivity onRestoreInstanceState------
07-24 08:54:26.079: I/System.out(18936): ------ TestActivity onResume------

c.再切换回竖屏的情况下：

07-24 08:55:02.099: I/System.out(18936): ------ TestActivity onPause------
07-24 08:55:02.109: I/System.out(18936): ------ TestActivity onSaveInstanceState------
07-24 08:55:02.119: I/System.out(18936): ------ TestActivity onStop------
07-24 08:55:02.129: I/System.out(18936): ------ TestActivity onDestroy------
07-24 08:55:02.139: D/memalloc(18936): /dev/pmem: Unmapping buffer base:0x5c7c5000 size:4608000 offset:3072000
07-24 08:55:02.139: D/memalloc(18936): /dev/pmem: Unmapping buffer base:0x5cc30000 size:9216000 offset:7680000
07-24 08:55:02.179: I/System.out(18936): ------ TestActivity onCreate------
07-24 08:55:02.249: I/System.out(18936): ------ TestActivity onStart------
07-24 08:55:02.289: I/System.out(18936): ------ TestActivity onRestoreInstanceState------
07-24 08:55:02.309: I/System.out(18936): ------ TestActivity onResume------

发觉上面的结果是跟网上的朋友说的不是一样的，原来是有区别的。

到后来去网上搜索了一下资料发觉，到了。4.0以后。要加上这样的配置才会使Activity的生命周期不会重新被调用

3)配置android:configChanges="keyboardHidden|orientation|screenSize" （4.0以后）

a.正常情况下：

07-24 08:54:05.059: I/System.out(18936): ------ TestActivity onCreate------
07-24 08:54:05.199: I/System.out(18936): ------ TestActivity onStart------
07-24 08:54:05.219: I/System.out(18936): ------ TestActivity onResume------

b.切换横屏情况下：

07-24 09:08:21.639: I/System.out(19533): ------ TestActivity onConfigurationChanged------

c.再切换回竖屏的情况下：

07-24 09:08:21.639: I/System.out(19533): ------ TestActivity onConfigurationChanged-----

总结：要想Activity在横竖屏切换的时候不重新加载生命周期的重要方法，一定要加上配置

4.0之前

<activity .....

android:configChanges="orientation|keyboardHidden"

>

4.0之后

<activity .....

android:configChanges="keyboardHidden|orientation|screenSize"

>

------------------------------------------------------常用设置---------------------------------------------------------

1.如果你的app指定要横屏显示的话

<activity .....

android:screenOrientation="portrait"

>

2.如果你的app指定要竖屏显示的话

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