WebView没有在Android 9.0中加载页面？

Question

 public abstract class MainActivity extends AppCompatActivity {

        private static WebView web;
        private WebView mWebView;
        private java.lang.String url;
        Boolean isInternetPresent = false;

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            ConnectivityManager manager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo i = manager.getActiveNetworkInfo();
            boolean hasConnect = (i != null && i.isConnected() && i.isAvailable());

            if (hasConnect) {
            } else {
            }
            Timer repeatTask = new Timer();
            repeatTask.scheduleAtFixedRate(new TimerTask() {
                @Override
                public void run() {
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            mWebView.loadUrl("http://www.smedk.ru/wp-content/uploads/files/education/rasp/1151.htm");
                        }
                    });
                }
            }, 0, 60000);

            setContentView(R.layout.activity_main);
            final ProgressDialog pd = ProgressDialog.show(MainActivity.this, "???????? ??????????...", "?????????? ??????...", true);
            mWebView = (WebView) findViewById(R.id.web1);
            mWebView.getSettings().setJavaScriptEnabled(true);
            if (savedInstanceState == null) {
                mWebView.loadUrl("http://www.smedk.ru/wp-content/uploads/files/education/rasp/1151.htm");
                mWebView.getSettings().setJavaScriptEnabled(true);
                mWebView.getSettings().setUseWideViewPort(true);
                String newUA = "User Agent";
                newUA = "Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.4) Gecko/20100101 Firefox/4.0";
                mWebView.getSettings().setUserAgentString(newUA);
                mWebView.getSettings().setLoadWithOverviewMode(true);
                mWebView.clearCache(true);
                mWebView.getSettings().setBuiltInZoomControls(true);
                mWebView.getSettings().setSupportZoom(true);
                mWebView.getSettings().setDisplayZoomControls(false);
            }
            mWebView.setWebViewClient(new MyWebViewClient());
            mWebView.setWebViewClient(new WebViewClient() {
                public void onReceivedError(WebView webView, int errorCode, String description, String failingUrl) {
                    try {
                        webView.stopLoading();
                    } catch (Exception e) {
                    }

                    if (webView.canGoBack()) {
                        webView.goBack();
                    }

                    webView.loadUrl("about:blank");
                    AlertDialog alertDialog = new AlertDialog.Builder(MainActivity.this).create();
                    alertDialog.setTitle("??? ???????? ???????????!");
                    alertDialog.setMessage("??????????? ?????????? ??????? ?? " +
                            "Wi-Fi ??? ????????? ?????? ? ????????? ???????. ");
                    alertDialog.setButton(DialogInterface.BUTTON_POSITIVE, "OK", new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int which) {
                            finish();
                        }
                    });

                    alertDialog.show();
                    super.onReceivedError(webView, errorCode, description, failingUrl);
                }

                @Override
                public void onPageStarted(WebView view, String url, Bitmap favicon) {
                    pd.show();
                }

                @Override
                public void onPageFinished(WebView view, String url) {
                    pd.dismiss();
                    Toast.makeText(MainActivity.this, "?????????? ?????????", Toast.LENGTH_SHORT).show();
                    Toast.makeText(MainActivity.this, "?????????? ?????? ?????????", Toast.LENGTH_SHORT).show();
                    String webUrl = mWebView.getUrl();
                }
            });
        }




        @Override
        protected void onSaveInstanceState(Bundle outState) {
            super.onSaveInstanceState(outState);
            mWebView.saveState(outState);
        }

        @Override
        protected void onRestoreInstanceState(Bundle savedInstanceState) {
            super.onSaveInstanceState(savedInstanceState);
            mWebView.restoreState(savedInstanceState);
            mWebView.setDownloadListener(new DownloadListener() {

                public void onDownloadStart(String url, String userAgent,
                                            String contentDisposition, String mimetype,
                                            long contentLength) {

                    DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
                    request.allowScanningByMediaScanner();

                    request.setNotificationVisibility(
                            DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);

                    request.setDestinationInExternalPublicDir(
                            Environment.DIRECTORY_DOWNLOADS,
                            "image.png");


                    DownloadManager dm = (DownloadManager) getSystemService(
                            DOWNLOAD_SERVICE);

                    dm.enqueue(request);

                }
            });
        }

        @Override
        public void onConfigurationChanged(Configuration newConfig) {
            super.onConfigurationChanged(newConfig);
        }

        private void TakeScreenshot() {
            Picture picture = mWebView.capturePicture();
            Bitmap b = Bitmap.createBitmap(picture.getWidth(),
                    picture.getHeight(), Bitmap.Config.ARGB_8888);
            Canvas c = new Canvas(b);

            picture.draw(c);
            FileOutputStream fos = null;
            try {

                fos = new FileOutputStream("mnt/sdcard/Download/image.jpg");
                if (fos != null) {
                    b.compress(Bitmap.CompressFormat.JPEG, 100, fos);

                    fos.close();
                }
            } catch (Exception e) {
            }
        }

        @Override
        public boolean onCreateOptionsMenu(Menu menu) {
            MenuInflater inflater = getMenuInflater();
            inflater.inflate(R.menu.menu, menu);
            return super.onCreateOptionsMenu(menu);
        }

        @Override
        public boolean onOptionsItemSelected(MenuItem item) {
            switch (item.getItemId()) {
                case R.id.exit:
                    finish();
                    break;
                case R.id.about:
                    Intent intent = new Intent(MainActivity.this, AboutActivity.class);
                    startActivity(intent);
                    break;
                case R.id.save:
                    Picture picture = mWebView.capturePicture();
                    Bitmap b = Bitmap.createBitmap(picture.getWidth(),
                            picture.getHeight(), Bitmap.Config.ARGB_8888);
                    Canvas c = new Canvas(b);
                    Toast.makeText(MainActivity.this, "??????????? ????????? ? ??????? JPG", Toast.LENGTH_SHORT).show();
                    Toast.makeText(MainActivity.this, "???? ?????????:" +
                            " /sdcard/image.jpg ", Toast.LENGTH_SHORT).show();
                    picture.draw(c);
                    FileOutputStream fos = null;
                    try {

                        fos = new FileOutputStream("mnt/sdcard/image.jpg");
                        if (fos != null) {
                            b.compress(Bitmap.CompressFormat.JPEG, 100, fos);

                            fos.close();
                        }
                    } catch (Exception e) {
                        break;
                    }
                    return true;
            }
            return false;
        }
    }

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

public class MyWebViewClient extends WebViewClient {
    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        view.loadUrl(url);
        return true;
    }
    @Override
    public void onPageFinished(WebView view, String url) {
        }
    }

我创建了一个查看调用计划的应用程序,并且通常决定在模拟器上测试我的应用程序.在旧版本上,webview工作正常,但当我决定在android 9上测试时,我写了一个不可用的网页.

在较旧版本的Android上,webView加载正常,但在Android 9上没有加载.是什么原因？

Answer 1

实际上你应该避免使用http,但如果你无法做到这一点:

1. 将@ xml/network_security_config添加到您的资源中:

   <?xml version="1.0" encoding="utf-8"?>
   <network-security-config>
       <domain-config cleartextTrafficPermitted="true">
           <domain includeSubdomains="true">www.smedk.ru</domain>
       </domain-config>
   </network-security-config>
   

2. 将此安全配置添加到您的清单中,如下所示:

   <application
       ...
       android:networkSecurityConfig="@xml/network_security_config"
       ...>
   
       ...
   </application>
   

3. 现在,您允许在www.smedk.ru子域上使用HTTP连接.

您可以在https://developer.android.com/training/articles/security-config#CleartextTrafficPermitted中阅读更多内容.

注意:本节中的指南仅适用于针对Android 8.1(API级别27)或更低级别的应用.从Android 9(API级别28)开始,默认情况下禁用明文支持.

Answer 2

此方法适用于Android 9的所有域.将此属性添加到您的Manifest,如下所示:

<application
    ...
   android:usesCleartextTraffic="true"
    ...>
</application>

Answer 3

请尝试使用安全网址。使用https而不是http。Android 9.0不允许使用不安全的网址