WebView（媒体相关）功能在 Android 7+ 中停止工作

Question

我有一个 WebView 应用程序，它从用户的设备上传图像并从 webView 本身播放音乐。这适用于 Marshmallow 和较低版本的 Android，但不适用于 Nougat 及更高版本。 模态中的图像也不会显示。

这是来自MainActivity.java的代码：

private File createImageFile() throws IOException {
        // Create an image file name
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        String imageFileName = "JPEG_" + timeStamp + "_";
        File storageDir = Environment.getExternalStoragePublicDirectory(
                Environment.DIRECTORY_PICTURES);
        File imageFile = File.createTempFile(
                imageFileName,  /* prefix */
                ".jpg",         /* suffix */
                storageDir      /* directory */
        );
        return imageFile;
    }

    public class PQChromeClient extends WebChromeClient {

        // For Android 5.0
        public boolean onShowFileChooser(WebView view, ValueCallback<Uri[]> filePath, WebChromeClient.FileChooserParams fileChooserParams) {
            // Double check that we don't have any existing callbacks
            if (mFilePathCallback != null) {
                mFilePathCallback.onReceiveValue(null);
            }
            mFilePathCallback = filePath;

            Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
            if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
                // Create the File where the photo should go
                File photoFile = null;
                try {
                    photoFile = createImageFile();
                    takePictureIntent.putExtra("PhotoPath", mCameraPhotoPath);
                } catch (IOException ex) {
                    // Error occurred while creating the File
                    Log.e(TAG, "Unable to create Image File", ex);
                }

                // Continue only if the File was successfully created
                if (photoFile != null) {
                    mCameraPhotoPath = "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("image/*");

            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, INPUT_FILE_REQUEST_CODE);

            return true;

        }

        // openFileChooser for Android 3.0+
        public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType) {

            mUploadMessage = uploadMsg;
            // Create AndroidExampleFolder at sdcard
            // Create AndroidExampleFolder at sdcard

            File imageStorageDir = new File(
                    Environment.getExternalStoragePublicDirectory(
                            Environment.DIRECTORY_PICTURES)
                    , "AndroidExampleFolder");

            if (!imageStorageDir.exists()) {
                // Create AndroidExampleFolder at sdcard
                imageStorageDir.mkdirs();
            }

            // Create camera captured image file path and name
            File file = new File(
                    imageStorageDir + File.separator + "IMG_"
                            + String.valueOf(System.currentTimeMillis())
                            + ".jpg");

            mCapturedImageURI = Uri.fromFile(file);

            // Camera capture image intent
            final Intent captureIntent = new Intent(
                    android.provider.MediaStore.ACTION_IMAGE_CAPTURE);

            captureIntent.putExtra(MediaStore.EXTRA_OUTPUT, mCapturedImageURI);

            Intent i = new Intent(Intent.ACTION_GET_CONTENT);
            i.addCategory(Intent.CATEGORY_OPENABLE);
            i.setType("image/*");

            // Create file chooser intent
            Intent chooserIntent = Intent.createChooser(i, "Image Chooser");

            // Set camera intent to file chooser
            chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS
                    , new Parcelable[] { captureIntent });

            // On select image call onActivityResult method of activity
            startActivityForResult(chooserIntent, FILECHOOSER_RESULTCODE);


        }

        // openFileChooser for Android < 3.0
        public void openFileChooser(ValueCallback<Uri> uploadMsg) {
            openFileChooser(uploadMsg, "");
        }

        //openFileChooser for other Android versions
        public void openFileChooser(ValueCallback<Uri> uploadMsg,
                                    String acceptType,
                                    String capture) {

            openFileChooser(uploadMsg, acceptType);
        }

    }
    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {

            if (requestCode != INPUT_FILE_REQUEST_CODE || mFilePathCallback == null) {
                super.onActivityResult(requestCode, resultCode, data);
                return;
            }

            Uri[] results = null;

            // Check that the response is a good one
            if (resultCode == Activity.RESULT_OK) {
                if (data == null) {
                    // If there is not data, then we may have taken a photo
                    if (mCameraPhotoPath != null) {
                        results = new Uri[]{Uri.parse(mCameraPhotoPath)};
                    }
                } else {
                    String dataString = data.getDataString();
                    if (dataString != null) {
                        results = new Uri[]{Uri.parse(dataString)};
                    }
                }
            }

            mFilePathCallback.onReceiveValue(results);
            mFilePathCallback = null;

        } else if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.KITKAT) {
            if (requestCode != FILECHOOSER_RESULTCODE || mUploadMessage == null) {
                super.onActivityResult(requestCode, resultCode, data);
                return;
            }

            if (requestCode == FILECHOOSER_RESULTCODE) {

                if (null == this.mUploadMessage) {
                    return;
                }

                Uri result = null;

                try {
                    if (resultCode != RESULT_OK) {

                        result = null;

                    } else {

                        // retrieve from the private variable if the intent is null
                        result = data == null ? mCapturedImageURI : data.getData();
                    }
                } catch (Exception e) {
                    Toast.makeText(getApplicationContext(), "activity :" + e,
                            Toast.LENGTH_LONG).show();
                }

                mUploadMessage.onReceiveValue(result);
                mUploadMessage = null;

            }
        }

        return;
    }
    private void startKioskService() { // ... and this method
        startService(new Intent(MainActivity.this, CheckTopActivityService.class));
    }

这里有什么问题？ Nougat 中是否有用于上传图片的新功能？还有为什么音乐没有播放？我是否应该请求允许才能播放音乐？

Answer 1

如果您的 targetSdkVersion 是 Nougat，我们必须使用 FileProvider 类来授予对特定文件或文件夹的访问权限，以便其他应用程序可以访问它们。我们创建自己的继承 FileProvider 的类，以确保我们的 FileProvider 不会与在导入的依赖项中声明的 FileProvider 冲突，如 Here 所述

希望对你有帮助。