Glass上的Android相机意图 - 将图像保存在自定义文件路径中

Question

我在尝试使用自定义文件名保存图像的 Android 活动中有以下代码。

我尝试从这篇文章的最佳答案中复制代码：Android - Taking photos and saving them with a custom name to a custom destination via Intent

我的代码如下：

    //camera stuff
    Intent imageIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());

    //folder stuff
    File imagesFolder = new File(Environment.getExternalStorageDirectory(), "MyImages");
    imagesFolder.mkdirs();
    File image = new File(imagesFolder, "QR_" + timeStamp + ".png");
    Uri uriSavedImage = Uri.fromFile(image);

    imageIntent.putExtra(MediaStore.EXTRA_OUTPUT, uriSavedImage);
    Log.d(LOG_TAG, "writing photo to: " + uriSavedImage.toString());
    startActivityForResult(imageIntent, 1);

当我运行这个活动时，它会在屏幕上显示一张图片，我必须点击触摸板才能接受（这是在 Glass 上运行的），它会在 DDMS 中打印以下内容：

writing photo to: file:///mnt/sdcard/MyImages/QR_20140106_181934.jpg

但是，当我通过 DDMS 在文件资源管理器中检查该目录时，它是空的。它成功创建了 MyImages 目录，但没有在该目录中保存任何文件。

相反，它使用我刚刚拍摄的图像创建了以下文件：/mnt/sdcard/DCIM/Camera/20140106_181935_635.jpg

所以它捕获了正确的图像，但只是忽略了我告诉它保存它的位置。任何想法我做错了什么？

Answer 1

文件可能没有写完整，所以使用FileWatcher，就像GDK docs中的那个：

private static final int TAKE_PICTURE_REQUEST = 1;

private void takePicture() {
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    startActivityForResult(intent, TAKE_PICTURE_REQUEST);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == TAKE_PICTURE_REQUEST && resultCode == RESULT_OK) {
        String picturePath = data.getStringExtra(
                CameraManager.EXTRA_PICTURE_FILE_PATH);
        processPictureWhenReady(picturePath);
    }

    super.onActivityResult(requestCode, resultCode, data);
}

private void processPictureWhenReady(final String picturePath) {
    final File pictureFile = new File(picturePath);

    if (pictureFile.exists()) {
        // The picture is ready; process it.
    } else {
        // The file does not exist yet. Before starting the file observer, you
        // can update your UI to let the user know that the application is
        // waiting for the picture (for example, by displaying the thumbnail
        // image and a progress indicator).

        final File parentDirectory = pictureFile.getParentFile();
        FileObserver observer = new FileObserver(parentDirectory.getPath()) {
            // Protect against additional pending events after CLOSE_WRITE is
            // handled.
            private boolean isFileWritten;

            @Override
            public void onEvent(int event, String path) {
                if (!isFileWritten) {
                    // For safety, make sure that the file that was created in
                    // the directory is actually the one that we're expecting.
                    File affectedFile = new File(parentDirectory, path);
                    isFileWritten = (event == FileObserver.CLOSE_WRITE
                            && affectedFile.equals(pictureFile));

                    if (isFileWritten) {
                        stopWatching();

                        // Now that the file is ready, recursively call
                        // processPictureWhenReady again (on the UI thread).
                        runOnUiThread(new Runnable() {
                            @Override
                            public void run() {
                                processPictureWhenReady(picturePath);
                            }
                        });
                    }
                }
            }
        };
        observer.startWatching();
    }
}