javascript - Webview不加载javascript获取内容

Question

我想获取 url 正文标记中的所有文本，但它不起作用。我搜索了很多，但找不到任何东西。我还添加了 android.permission.INTERNET。

那么问题是什么？

这是我的代码:

public class Activity_Main  extends Activity {

@SuppressLint("JavascriptInterface")
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    final WebView webView = (WebView) findViewById(R.id.webView);

    webView.getSettings().setJavaScriptEnabled(true);
    webView.getSettings().setDomStorageEnabled(true);

    final TextView contentView = (TextView) findViewById(R.id.contentView);

    class MyJavaScriptInterface
    {
        private TextView contentView;

        public MyJavaScriptInterface(TextView aContentView)
        {
            contentView = aContentView;
        }

        @SuppressWarnings("unused")

        public void processContent(String aContent)
        {
            final String content = aContent;
            contentView.setText(content);
        }
    }

    webView.getSettings().setJavaScriptEnabled(true);
    webView.addJavascriptInterface(new MyJavaScriptInterface(contentView), "INTERFACE");
    webView.setWebViewClient(new WebViewClient() {
        @Override
        public void onPageFinished(WebView view, String url)
        {
            webView.loadUrl("javascript:window.INTERFACE.processContent(document.getElementsByTagName('body')[0].innerText);");
        }
    });

    webView.loadUrl("https://stackoverflow.com");
  }
} 

Answer 1

为你的接口(interface)函数更新@JavascriptInterface并检查

class MyJavaScriptInterface
    {
        private TextView contentView;

        public MyJavaScriptInterface(TextView aContentView)
        {
            contentView = aContentView;
        }

        @JavascriptInterface
        public void processContent(String aContent)
        {
            final String content = aContent;
            contentView.setText(content);
        }
    }

对于上面的 KITKAT，还有另一种方法可以做到这一点

 webView.evaluateJavascript("alert('pass here some ...')", new ValueCallback<String>() {
       @Override
       public void onReceiveValue(String s) {

        }
    });

这是在android中执行js的更新方案

完整代码在这里

final WebView webView = (WebView) findViewById(R.id.webView);

    webView.getSettings().setJavaScriptEnabled(true);
    webView.getSettings().setDomStorageEnabled(true);

    final TextView contentView = (TextView) findViewById(R.id.contentView);

    class MyJavaScriptInterface
    {
        private TextView contentView;

        public MyJavaScriptInterface(TextView aContentView)
        {
            contentView = aContentView;
        }

        @JavascriptInterface
        public void processContent(String aContent)
        {
            final String content = aContent;
            contentView.setText(content);
        }
    }

    webView.getSettings().setJavaScriptEnabled(true);
    webView.addJavascriptInterface(new MyJavaScriptInterface(contentView), "INTERFACE");
    webView.setWebViewClient(new WebViewClient() {
        @Override
        public void onPageFinished(WebView view, String url)
        {
            super.onPageFinished(view,url);


            if (Build.VERSION.SDK_INT>=Build.VERSION_CODES.KITKAT) {
                webView.evaluateJavascript("document.getElementsByTagName('body')[0].innerText", new ValueCallback<String>() {
                    @Override
                    public void onReceiveValue(String s) {
                        contentView.setText(s);
                    }
                });
            }
            else {
                webView.loadUrl("javascript:window.INTERFACE.processContent(document.getElementsByTagName('body')[0].innerText)");

            }


                       }
    });

    webView.loadUrl("https://stackoverflow.com");