Android入门之系统设置Configuration类的使用教程

package org.mk.android.demo;
 
import androidx.appcompat.app.AppCompatActivity;
 
import android.content.res.Configuration;
import android.os.Bundle;
import android.widget.TextView;
 
import java.util.Locale;
 
public class MainActivity extends AppCompatActivity {
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TextView txtResult = (TextView) findViewById(R.id.tvConfInfor);
        StringBuffer status = new StringBuffer();
        //①获取系统的Configuration对象
        Configuration cfg = getResources().getConfiguration();
        //②想查什么查什么
        status.append("densityDpi:" + cfg.densityDpi + "\n");
        status.append("fontScale:" + cfg.fontScale + "\n");
        status.append("hardKeyboardHidden:" + cfg.hardKeyboardHidden + "\n");
        status.append("keyboard:" + cfg.keyboard + "\n");
        status.append("keyboardHidden:" + cfg.keyboardHidden + "\n");
 
        status.append("locale:" + Locale.getDefault() + "\n");
        status.append("mcc:" + cfg.mcc + "\n");
        status.append("mnc:" + cfg.mnc + "\n");
        status.append("navigation:" + cfg.navigation + "\n");
        status.append("navigationHidden:" + cfg.navigationHidden + "\n");
        status.append("orientation:" + cfg.orientation + "\n");
        status.append("screenHeightDp:" + cfg.screenHeightDp + "\n");
        status.append("screenWidthDp:" + cfg.screenWidthDp + "\n");
        status.append("screenLayout:" + cfg.screenLayout + "\n");
        status.append("smallestScreenWidthDp:" + cfg.densityDpi + "\n");
        status.append("touchscreen:" + cfg.densityDpi + "\n");
        status.append("uiMode:" + cfg.densityDpi + "\n");
        txtResult.setText(status.toString());
    }
}

package org.mk.android.demorotatelandscape;
 
import androidx.appcompat.app.AppCompatActivity;
 
import android.content.pm.ActivityInfo;
import android.content.res.Configuration;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
 
public class MainActivity extends AppCompatActivity {
 
    private Button buttonRotate;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button btn = (Button) findViewById(R.id.buttonRotate);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Configuration config = getResources().getConfiguration();
                //如果是横屏的话切换成竖屏
                if(config.orientation == Configuration.ORIENTATION_LANDSCAPE)
                {
                    MainActivity.this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
                }
                //如果竖屏的话切换成横屏
                if(config.orientation == Configuration.ORIENTATION_PORTRAIT)
                {
                    MainActivity.this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
                }
            }
        });
    }
    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        String screen = newConfig.orientation == Configuration.ORIENTATION_LANDSCAPE?"横屏":"竖屏";
        Toast.makeText(MainActivity.this, "系统屏幕方向发生改变 \n 修改后的方向为" + screen, Toast.LENGTH_SHORT).show();
    }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">
 
    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.DemoRotateLANDSCAPE"
        tools:targetApi="31">
        <activity
            android:name=".MainActivity"
            android:configChanges="orientation|screenSize"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
 
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
 
            <meta-data
                android:name="android.app.lib_name"
                android:value="" />
        </activity>
    </application>
 
</manifest>