Android 实现WebView

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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:layout_height="match_parent"
    tools:context=".MainActivity">

    <WebView
        android:id="@+id/webview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="Hello World!"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

AndroidManifest.xml

<uses-permission android:name="android.permission.INTERNET"></uses-permission>

 <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:supportsRtl="true"
++      android:usesCleartextTraffic="true"
        android:theme="@style/Theme.WebViewDemo"
        tools:targetApi="31">

MainActivity.java

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        WebView webView = findViewById(R.id.webview);
//如果页面中使用了JavaScript，不加改代码页面不显示。
        webView.getSettings().setJavaScriptEnabled(true);
//加载页面时如果不加改代码，页面会跳转到系统自带浏览器显示。
        webView.setWebViewClient(new WebViewClient(){
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                view.loadUrl(url);
                return true;//返回值为true时在WebView中打开，为false时调用浏览器打开
            }
        });
//显示页面
        webView.loadUrl("https://www.baidu.com/");//网络地址http://，本地地址file:///
    }
}