我有以下问题:我正在开发一个应用程序,用户可以拍照(以附加到帖子),并将照片保存到外部存储。我希望这张照片也会出现在图片库中,并且我正在使用媒体扫描器意图来实现,但似乎没有起作��。在编写代码时,我遵循了官方的Android开发者指南,所以不知道出了什么问题。
我的代码部分:
用于拍摄图像的意图:
private void dispatchTakePictureIntent() {
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
// Ensure that there's a camera activity to handle the intent
if (takePictureIntent.resolveActivity(getActivity().getPackageManager()) != null) {
// Create the File where the photo should go
File photoFile = null;
try {
photoFile = createImageFile();
} catch (IOException ex) {
// Error occurred while creating the File
Toast.makeText(getActivity(), ex.getMessage(), Toast.LENGTH_SHORT).show();
}
// Continue only if the File was successfully created
if (photoFile != null) {
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT,
Uri.fromFile(photoFile));
startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE);
}
}
}
创建一个文件以保存图像:
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 image = File.createTempFile(
imageFileName, /* prefix */
".jpg", /* suffix */
storageDir /* directory */
);
// Save a file: path for use with ACTION_VIEW intents
mCurrentPhotoPath = image.getAbsolutePath();
return image;
}
在视图中显示图片:
private void setPic() {
// Get the dimensions of the View
int targetW = 60;
int targetH = 100;
// Get the dimensions of the bitmap
BitmapFactory.Options bmOptions = new BitmapFactory.Options();
bmOptions.inJustDecodeBounds = true;
BitmapFactory.decodeFile(mCurrentPhotoPath, bmOptions);
int photoW = bmOptions.outWidth;
int photoH = bmOptions.outHeight;
// Determine how much to scale down the image
int scaleFactor = Math.min(photoW/targetW, photoH/targetH);
// Decode the image file into a Bitmap sized to fill the View
bmOptions.inJustDecodeBounds = false;
bmOptions.inSampleSize = scaleFactor;
bmOptions.inPurgeable = true;
Bitmap bitmap = BitmapFactory.decodeFile(mCurrentPhotoPath, bmOptions);
img_added.setImageBitmap(bitmap);
}
广播媒体扫描器意图,使图像在图库中显示:
private void galleryAddPic() {
Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
File f = new File(mCurrentPhotoPath);
Uri contentUri = Uri.fromFile(f);
mediaScanIntent.setData(contentUri);
getActivity().sendBroadcast(mediaScanIntent);
}
在图像捕获意图返回后运行的代码:
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == Activity.RESULT_OK) {
setPic();
galleryAddPic();
}
}
我还尝试使用
Intent.ACTION_MEDIA_MOUNTED
而不是Intent.ACTION_MEDIA_SCANNER_SCAN_FILE
,但在这种情况下,我得到了一个“权限被拒绝”的错误。当我记录传递给意图的URI时,我得到了file:///storage/emulated/0/Pictures/JPEG_20150803_104122_-1534770215.jpg
,这应该没问题。除此之外,其他所有操作都正常(捕获图像、将其保存到外部存储器并在视图中显示),所以我真的不知道出了什么问题。有人有任何想法吗?提前致谢!