android webview全屏显示html内容

1. MainActivity.java文件修改

   package com.example.wwy.webviewdemo;
   
   import android.support.v7.app.AppCompatActivity;
   import android.os.Bundle;
   import android.app.Activity;
   import android.view.KeyEvent;
   import android.webkit.WebView;
   import android.view.Window;
   import android.view.WindowManager;
   
   public class MainActivity extends AppCompatActivity {
       private WebView webview;
   
       @Override
       protected void onCreate(Bundle savedInstanceState) {
           super.onCreate(savedInstanceState);
   
           Window window = getWindow();
           //隐藏标题栏
           requestWindowFeature(Window.FEATURE_NO_TITLE);//隐藏状态栏
           //定义全屏参数
           int flag=WindowManager.LayoutParams.FLAG_FULLSCREEN;
           //设置当前窗体为全屏显示
           window.setFlags(flag, flag);
   
           //setContentView(R.layout.activity_main);
           //实例化WebView对象
           webview = new WebView(this);
   
           //[*关键的三行start]
           //设置WebView属性，能够执行Javascript脚本
           webview.getSettings().setJavaScriptEnabled(true);
           webview.getSettings().setAllowFileAccessFromFileURLs(true);
           webview.getSettings().setAllowUniversalAccessFromFileURLs(true);
           //[*关键的三行end]
   
           //加载需要显示的网页
           webview.loadUrl("https://www.baidu.com");
           //设置Web视图
           setContentView(webview);
       }
   
       @Override
       public boolean onKeyDown(int keyCode, KeyEvent event) {
           if((keyCode == KeyEvent.KEYCODE_BACK) && webview.canGoBack() ){
               webview.goBack();
               return  true;
           }
           return  false;
       }
   }

2. AndroidManifest.xml修改

   <?xml version="1.0" encoding="utf-8"?>
   <manifest xmlns:android="http://schemas.android.com/apk/res/android"
       package="com.example.wwy.webviewdemo">
   
       <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/Theme.AppCompat.NoActionBar">
           <activity android:name=".MainActivity" android:screenOrientation="portrait">
   
               <intent-filter>
                   <action android:name="android.intent.action.MAIN" />
   
                   <category android:name="android.intent.category.LAUNCHER" />
               </intent-filter>
           </activity>
       </application>
       <uses-permission android:name="android.permission.INTERNET"/>
   </manifest>