Android开发：如何让WebView正常工作？

Hey there! It looks like you're well on your way to setting up a WebView in your Android app. You've knocked out the initial setup steps, so let's fill in the missing pieces to get it fully functional.

What You've Already Completed (Great Start!) #

You've checked off the foundational steps perfectly:

• Imported the required WebView classes:

  import android.webkit.WebView;
  import android.webkit.WebViewClient;
  

• Added the critical internet permission to your AndroidManifest.xml:

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

• Started building out the onCreate method to initialize your WebView:

  private WebView webview;
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      webview = (WebView) findViewById(R.id.webview); // Make sure your layout has a WebView with this ID!
  

Completing the WebView Configuration & Loading Logic #

To make your WebView work as expected (load web pages internally instead of opening the system browser, and enable necessary features like JavaScript), here's the full onCreate implementation:

private WebView webview;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    webview = (WebView) findViewById(R.id.webview);

    // Enable JavaScript if your target webpage requires it
    WebSettings webSettings = webview.getSettings();
    webSettings.setJavaScriptEnabled(true);

    // Set a WebViewClient to keep page navigation within the WebView
    webview.setWebViewClient(new WebViewClient() {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            view.loadUrl(url);
            return true;
        }
    });

    // Load your target webpage here
    webview.loadUrl("https://your-desired-website.com");
}

Don't Forget the Layout File! #

You need to add the WebView component to your activity_main.xml layout (make sure the ID matches what you use in findViewById):

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <WebView
        android:id="@+id/webview"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

Extra Tips for Smooth Operation #

• Cleartext Traffic (Android 11+): If you're loading an HTTP (not HTTPS) webpage, add this to your AndroidManifest.xml inside the <application> tag to avoid errors:

  android:usesCleartextTraffic="true"
  

• Lifecycle Management: Prevent memory leaks and improve performance by handling the WebView's lifecycle:

  @Override
  protected void onPause() {
      super.onPause();
      webview.onPause();
  }
  
  @Override
  protected void onResume() {
      super.onResume();
      webview.onResume();
  }
  
  @Override
  protected void onDestroy() {
      super.onDestroy();
      webview.destroy();
  }
  

内容的提问来源于stack exchange，提问作者Jay1995