Question

尝试使按钮拍摄照片并在imageview中显示。我正在临时保存该图像以具有更好的质量。相机无法正常工作，但imageview上没有任何显示

    private void dispatchTakePictureIntent() {
    Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

    if (takePictureIntent.resolveActivity(getPackageManager()) != null) {

        File photoFile = null;
        try {
            photoFile = createImageFile();
        } catch (IOException ex) {

        }
        if (photoFile != null) {
            Uri photoURI = FileProvider.getUriForFile(this,
                    "com.example.l_sliuzas.fileprovider",
                    photoFile);
            takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
            startActivityForResult(takePictureIntent, REQUEST_TAKE_PHOTO);
        }
    }
}



@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == REQUEST_TAKE_PHOTO && requestCode == RESULT_OK)
    {
        Bitmap bitmapas = BitmapFactory.decodeFile(mCurrentPhotoPath);
        mImageView.setImageBitmap(bitmapas);
    }
}

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 = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
    File image = File.createTempFile(
            imageFileName,  /* prefix */
            ".jpg",         /* suffix */
            storageDir      /* directory */
    );

    mCurrentPhotoPath = image.getAbsolutePath();
    return image;
}

Answer 1

这里REQUEST_TAKE_PHOTO是requestCode，而RESULT_OK是resultCode。但是在onActivityResult内部，您正在使用requestCode进行评估。哪个不正确。

所以下面的代码不正确

if (requestCode == REQUEST_TAKE_PHOTO && requestCode == RESULT_OK)
    {
        Bitmap bitmapas = BitmapFactory.decodeFile(mCurrentPhotoPath);
        mImageView.setImageBitmap(bitmapas);
    }

将其更改为

if (requestCode == REQUEST_TAKE_PHOTO && resultCode == RESULT_OK)
    {
        Bitmap bitmapas = BitmapFactory.decodeFile(mCurrentPhotoPath);
        mImageView.setImageBitmap(bitmapas);
    }

无法弄清楚为什么总是存在空值

1 个答案: