android - 一旦在 Webview 中上传文件，ProgressDialog 就会消失

Question

我有 webview 代码，它在从一个页面转到另一个页面时显示处理圈。

在我们上传一些文件之前，代码运行良好。一旦文件被上传，用户就会重定向到另一个页面。经过这个从一个页面显示到另一个页面的处理圈就完全不显示了。

我尝试用谷歌搜索这个主题，但没有用，看起来这是网络上的新问题，哈哈。

还有另一个关于 javascript alert box 的问题。它没有给定标题，而是显示 “The page at http://example.com says:”。尝试了网络上的解决方案但没有用...

如果有人能在这里指出潜在的问题，那将非常有帮助。谢谢...

下面是我的代码:

import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.pm.PackageManager;
import android.content.res.Configuration;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.os.Parcelable;
import android.preference.PreferenceManager;
import android.provider.MediaStore;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.util.Log;
import android.view.View;
import android.webkit.ConsoleMessage;
import android.webkit.JsResult;
import android.webkit.ValueCallback;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;
import com.google.firebase.iid.FirebaseInstanceId;
import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import static android.content.ContentValues.TAG;

    public class MainActivity extends Activity {
        public static WebView mWebview;
        private android.content.Context Context;
        private static String getIntentValue = null;
        public static SharedPreferences sharedPreferences;
        private ProgressDialog mProgressDialog;
        private String mCM;
        private ValueCallback<Uri> mUM;
        private ValueCallback<Uri[]> mUMA;
        private final static int FCR=1;

        @Override
        protected void onActivityResult(int requestCode, int resultCode, Intent intent){
            super.onActivityResult(requestCode, resultCode, intent);
            mWebview.setWebViewClient(new Callback());
            if(Build.VERSION.SDK_INT >= 21){
                Uri[] results = null;
                //Check if response is positive
                if(resultCode== Activity.RESULT_OK){
                    if(requestCode == FCR){
                        if(null == mUMA){
                            return;
                        }
                        if(intent == null){
                            //Capture Photo if no image available
                            if(mCM != null){
                                results = new Uri[]{Uri.parse(mCM)};
                            }
                        }else{
                            String dataString = intent.getDataString();
                            if(dataString != null){
                                results = new Uri[]{Uri.parse(dataString)};
                            }
                        }
                    }
                }
                mUMA.onReceiveValue(results);
                mUMA = null;
            }else{
                if(requestCode == FCR){
                    if(null == mUM) return;
                    Uri result = intent == null || resultCode != RESULT_OK ? null : intent.getData();
                    mUM.onReceiveValue(result);
                    mUM = null;
                }
            }
        }
        private void enableHTML5AppCache() {
            mWebview.getSettings().setDomStorageEnabled(true);
            mWebview.getSettings().setAppCachePath("/data/data/" + getPackageName() + "/cache");
            mWebview.getSettings().setAppCacheEnabled(true);
            mWebview.getSettings().setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK);
        }
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);

            setContentView(R.layout.activity_main);
            Context = this;
            String regId = FirebaseInstanceId.getInstance().getToken();

            getIntentValue = getIntent().getStringExtra("value");

            sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);

            if (!DetectConnection.checkInternetConnection(this)) {
                Toast.makeText(getApplicationContext(), "No Internet Connection!", Toast.LENGTH_LONG).show();
             //   finish(); //Calling this method to close this activity when internet is not available.

            } else {

                mWebview = (WebView) findViewById(R.id.webview1);
                WebSettings webSettings = mWebview.getSettings();
                mWebview.getSettings().setJavaScriptEnabled(true);
                mWebview.setWebChromeClient(new WebChromeClient());
                mWebview.setWebChromeClient(new JsPopupWebViewChrome());            mWebview.setWebViewClient(new CustomWebViewClient());

                //improve WebView Performance
                mWebview.getSettings().setRenderPriority(WebSettings.RenderPriority.HIGH);
                mWebview.getSettings().setAppCacheEnabled(true);
                mWebview.getSettings().setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK);

                if(Build.VERSION.SDK_INT >= 21){
                    webSettings.setMixedContentMode(0);
                    mWebview.setLayerType(View.LAYER_TYPE_HARDWARE, null);
                }else if(Build.VERSION.SDK_INT >= 19){
                    mWebview.setLayerType(View.LAYER_TYPE_HARDWARE, null);
                }else if(Build.VERSION.SDK_INT < 19){
                    mWebview.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
                }

                if(Build.VERSION.SDK_INT >=23 && (ContextCompat.checkSelfPermission(this, android.Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED || ContextCompat.checkSelfPermission(this, android.Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED)) {
                    ActivityCompat.requestPermissions(MainActivity.this, new String[]{android.Manifest.permission.WRITE_EXTERNAL_STORAGE, android.Manifest.permission.CAMERA}, 1);
                }

                mWebview.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);
                webSettings.setDomStorageEnabled(true);
                webSettings.setLayoutAlgorithm(WebSettings.LayoutAlgorithm.NARROW_COLUMNS);
                webSettings.setUseWideViewPort(true);
                webSettings.setAllowFileAccess(true);
                webSettings.setSavePassword(true);
                webSettings.setSaveFormData(true);
                webSettings.setEnableSmoothTransition(true);
                enableHTML5AppCache();
                // progress dialog
                mProgressDialog = new ProgressDialog(Context);

                if (sharedPreferences.getBoolean("isKeyGenerated", true)) {

                    if (getIntentValue != null) {
                        mWebview.loadUrl("http://example.com");
                        getIntentValue = null;

                    } else {
                        mWebview.loadUrl("http://example.com");
                    }
                }
            }

            mWebview.setWebChromeClient(new WebChromeClient(){
                //For Android 3.0+
                public void openFileChooser(ValueCallback<Uri> uploadMsg){
                    mUM = uploadMsg;
                    Intent i = new Intent(Intent.ACTION_GET_CONTENT);
                    i.addCategory(Intent.CATEGORY_OPENABLE);
                    i.setType("*/*");
                    MainActivity.this.startActivityForResult(Intent.createChooser(i,"File Chooser"), FCR);
                }
                // For Android 3.0+, above method not supported in some android 3+ versions, in such case we use this
                public void openFileChooser(ValueCallback uploadMsg, String acceptType){
                    mUM = uploadMsg;
                    Intent i = new Intent(Intent.ACTION_GET_CONTENT);
                    i.addCategory(Intent.CATEGORY_OPENABLE);
                    i.setType("*/*");
                    MainActivity.this.startActivityForResult(
                            Intent.createChooser(i, "File Browser"),
                            FCR);
                }
                //For Android 4.1+
                public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture){
                    mUM = uploadMsg;
                    Intent i = new Intent(Intent.ACTION_GET_CONTENT);
                    i.addCategory(Intent.CATEGORY_OPENABLE);
                    i.setType("*/*");
                    MainActivity.this.startActivityForResult(Intent.createChooser(i, "File Chooser"), MainActivity.FCR);
                }
                //For Android 5.0+
                public boolean onShowFileChooser(
                        WebView webView, ValueCallback<Uri[]> filePathCallback,
                        WebChromeClient.FileChooserParams fileChooserParams){
                    if(mUMA != null){
                        mUMA.onReceiveValue(null);
                    }
                    mUMA = filePathCallback;
                    Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                    if(takePictureIntent.resolveActivity(MainActivity.this.getPackageManager()) != null){
                        File photoFile = null;
                        try{
                            photoFile = createImageFile();
                            takePictureIntent.putExtra("PhotoPath", mCM);
                        }catch(IOException ex){
                            Log.e(TAG, "Image file creation failed", ex);
                        }
                        if(photoFile != null){
                            mCM = "file:" + photoFile.getAbsolutePath();
                            takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photoFile));
                        }else{
                            takePictureIntent = null;
                        }
                    }
                    Intent contentSelectionIntent = new Intent(Intent.ACTION_GET_CONTENT);
                    contentSelectionIntent.addCategory(Intent.CATEGORY_OPENABLE);
                    contentSelectionIntent.setType("*/*");
                    Intent[] intentArray;
                    if(takePictureIntent != null){
                        intentArray = new Intent[]{takePictureIntent};
                    }else{
                        intentArray = new Intent[0];
                    }

                    Intent chooserIntent = new Intent(Intent.ACTION_CHOOSER);
                    chooserIntent.putExtra(Intent.EXTRA_INTENT, contentSelectionIntent);
                    chooserIntent.putExtra(Intent.EXTRA_TITLE, "Image Chooser");
                    chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, intentArray);
                    startActivityForResult(chooserIntent, FCR);
                    return true;
                }
            });
        }

        private class JsPopupWebViewChrome extends WebChromeClient {
            @Override
            public boolean onJsConfirm(WebView view, String url, String message, final JsResult result) {
                AlertDialog.Builder b = new AlertDialog.Builder(view.getContext())
                        .setTitle("ALERT!")
                        .setMessage(message)
                        .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                result.confirm();
                            }
                        })
                        .setNegativeButton(android.R.string.cancel, new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                result.cancel();
                            }
                        });

                b.show();

                // Indicate that we're handling this manually
                return true;
            }
        }

        public class Callback extends WebViewClient{
            public void onReceivedError(WebView view, int errorCode, String description, String failingUrl){
                Toast.makeText(getApplicationContext(), "Failed loading app!", Toast.LENGTH_SHORT).show();
            }
        }

        // Create an image file
        private File createImageFile() throws IOException {
            @SuppressLint("SimpleDateFormat") String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
            String imageFileName = "img_"+timeStamp+"_";
            File storageDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
            return File.createTempFile(imageFileName,".jpg",storageDir);
        }

        // Function to load all URLs in same webview
        private class CustomWebViewClient extends WebViewClient {
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                if (!DetectConnection.checkInternetConnection(Context)) {
                    if (url.contains("http://example.com")){ //              Log.d("offline url", url);
                        view.loadUrl(url);
                    }else {
                        Toast.makeText(Context, "No Internet Connection!", Toast.LENGTH_SHORT).show(); //                    Log.d("other urls", url);
                    }
                }  else if (url.contains(".pdf")) {
                    Intent i = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
                    startActivity(i);
                } else {
                    view.loadUrl(url);
                }
                return true;
            }

            @Override
            public void onPageStarted(WebView view, String url, Bitmap favicon) {
                // TODO Auto-generated method stub
                super.onPageStarted(view, url, favicon);

                //on page started, show loading page
                mProgressDialog.setCancelable(true);
                mProgressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
                mProgressDialog.show();
            }

            @Override
            public void onPageFinished(WebView view, String url)
            {
                String currentPage= mWebview.getUrl();

                SharedPreferences.Editor editor = sharedPreferences.edit();
                editor.putString("currentpage",currentPage);
                editor.commit();

                //after loading page, remove loading page

                // TODO Auto-generated method stub
                super.onPageFinished(view, url);
                mProgressDialog.dismiss();
            }

            @Override
            public void onReceivedError(WebView view, int errorCode,
                                        String description, String failingUrl) { //            Log.e(TAG," Error occured while loading the web page at Url"+ failingUrl+"." +description); //
                Intent intent = new Intent(MainActivity.this, noconnection.class);
                intent.putExtra("a", "mainactivity is source");
                startActivity(intent); //
                Toast.makeText(getApplicationContext(), "Error occured, please check network connectivity", Toast.LENGTH_SHORT).show();
               // super.onReceivedError(view, errorCode, description, failingUrl);
            }

        }

        @Override
        public void onBackPressed() {
            SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
            String currenturl = sharedPreferences.getString("currentpage", null);

            mWebview.requestFocus();

            if (!DetectConnection.checkInternetConnection(Context)) {
                mWebview.loadUrl("http://example.com");
            }else if (currenturl.contains("http://example.com")){
                moveTaskToBack(true);
            }else if(currenturl.contains("http://example.com")){
                mWebview.loadUrl("http://example.com");
            }else if(currenturl.contains("http://example.com")){            mWebview.loadUrl("http://example.com");         }else{
                mWebview.goBack();
            }

            if (mWebview.canGoBack()) {
                if (!DetectConnection.checkInternetConnection(Context)) {
                    Toast.makeText(Context, "No Internet Connection!", Toast.LENGTH_SHORT).show();
                }

            }
        }


        public static void loadUrl(String key) {

            if (getIntentValue != null) {
                mWebview.loadUrl("http://example.com");
                getIntentValue = null;
            } else {
                mWebview.loadUrl("http://example.com");
            }

        }


        public static void reLoad() {
            mWebview.reload();
        }

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


} }

Answer 1

也许您应该覆盖 WebChromeClient 的 onProgressChanged 并在其中控制对话框。