如何在Android中处理屏幕方向变化？

此示例演示了如何在Android中处理屏幕方向变化。

步骤 1 - 在Android Studio中创建一个新项目，转到文件 ⇒ 新建项目，并填写所有必需的详细信息以创建新项目。

步骤 2 - 将以下代码添加到res/layout/activity_main.xml。

<?xml version = "1.0" encoding = "utf-8"?>
<LinearLayout xmlns:android = "http://schemas.android.com/apk/res/android"
   xmlns:app = "http://schemas.android.com/apk/res-auto"
   xmlns:tools = "http://schemas.android.com/tools"
   android:layout_width = "match_parent"
   android:gravity = "center"
   android:layout_height = "match_parent"
   tools:context = ".MainActivity"
   android:orientation = "vertical">
   <TextView
      android:id = "@+id/actionEvent"
      android:textSize = "40sp"
      android:layout_marginTop = "30dp"
      android:layout_width = "wrap_content"
      android:layout_height = "match_parent" />
</LinearLayout>

在以上代码中，我们使用了文本视图来显示方向变化。

步骤 3 - 将以下代码添加到src/MainActivity.java

package com.example.myapplication;
import android.content.res.Configuration;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.RequiresApi;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
   TextView actionEvent;
   @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      actionEvent = findViewById(R.id.actionEvent);
   }
   @Override
   public void onConfigurationChanged(Configuration newConfig) {
      super.onConfigurationChanged(newConfig);
      if (newConfig.orientation == Configuration.ORIENTATION_LANDSCAPE) {
         actionEvent.setText("ORIENTATION LANDSCAPE");
      } else {
         actionEvent.setText("ORIENTATION PORTRAIT");
      }
   }
}

步骤 4 - 将以下代码添加到manifest.xml

<?xml version = "1.0" encoding = "utf-8"?>
<manifest xmlns:android = "http://schemas.android.com/apk/res/android"
   package = "com.example.myapplication">
   <application
      android:allowBackup = "true"
      android:icon = "@mipmap/ic_launcher"
      android:label = "@string/app_name"
      android:roundIcon = "@mipmap/ic_launcher_round"
      android:supportsRtl = "true"
      android:theme = "@style/AppTheme">
      <activity android:name = ".MainActivity"
         android:configChanges = "keyboardHidden|orientation|screenSize">
         <intent-filter>
            <action android:name = "android.intent.action.MAIN" />
            <action android:name = "android.net.conn.CONNECTIVITY_CHANGE" />
            <category android:name = "android.intent.category.LAUNCHER" />
         </intent-filter>
      </activity>
   </application>
</manifest>