在某个点击事件中，我要求用户添加图像。所以我提供了两种选择：
我的目标是保留与这些图像相关的“uri”列表。
如果用户选择画廊，那么我会得到图像 uri（这很简单）。 但是如果他选择了相机，那么在拍照后，我就得到了那张照片的 Bitmap 对象。
现在如何将该位图对象转换为 uri，或者换句话说，如何获取该位图对象的相对 Uri 对象？
谢谢。
【问题讨论】：
我的项目也有同样的问题，所以我按照简单的方法（click here）从位图中获取 Uri。
public Uri getImageUri(Context inContext, Bitmap inImage) {
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
inImage.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
String path = MediaStore.Images.Media.insertImage(inContext.getContentResolver(), inImage, "Title", null);
return Uri.parse(path);
}
【讨论】：
Images.Media.insertImage 现在是 MediaStore.Images.Media.insertImage 添加此权限需要记住的第二件事：<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
returns path 和三星returns null。有什么帮助吗？
Images.Media.insertImage(inContext.getContentResolver(), inImage, "Title", null);
上面提到的行使用位图创建缩略图，这可能会占用你的安卓设备中的一些额外空间。
此方法可以帮助您从位图中获取 Uri 而不会消耗一些额外的内存。
public Uri bitmapToUriConverter(Bitmap mBitmap) {
Uri uri = null;
try {
final BitmapFactory.Options options = new BitmapFactory.Options();
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, 100, 100);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
Bitmap newBitmap = Bitmap.createScaledBitmap(mBitmap, 200, 200,
true);
File file = new File(getActivity().getFilesDir(), "Image"
+ new Random().nextInt() + ".jpeg");
FileOutputStream out = getActivity().openFileOutput(file.getName(),
Context.MODE_WORLD_READABLE);
newBitmap.compress(Bitmap.CompressFormat.JPEG, 100, out);
out.flush();
out.close();
//get absolute path
String realPath = file.getAbsolutePath();
File f = new File(realPath);
uri = Uri.fromFile(f);
} catch (Exception e) {
Log.e("Your Error Message", e.getMessage());
}
return uri;
}
public static int calculateInSampleSize(
BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
final int halfHeight = height / 2;
final int halfWidth = width / 2;
// Calculate the largest inSampleSize value that is a power of 2 and keeps both
// height and width larger than the requested height and width.
while ((halfHeight / inSampleSize) >= reqHeight
&& (halfWidth / inSampleSize) >= reqWidth) {
inSampleSize *= 2;
}
}
return inSampleSize;
}
【讨论】：
Bitmap newBitmap = Bitmap.createScaledBitmap(mBitmap, mBitmap.getWidth(), mBitmap.getHeight(), true);
这对我有用。例如，以位图的形式从视频中获取缩略图。然后我们可以将位图对象转换为uri对象。
String videoPath = mVideoUri.getEncodedPath();
System.out.println(videoPath); //prints to console the path of the saved video
Bitmap thumb = ThumbnailUtils.createVideoThumbnail(videoPath, MediaStore.Images.Thumbnails.MINI_KIND);
Uri thumbUri = getImageUri(this, thumb);
【讨论】：
我尝试了post I mentioned in my comment.. 中的以下代码 sn-p，它对我来说工作正常。
/**
* Gets the last image id from the media store
*
* @return
*/
private int getLastImageId() {
final String[] imageColumns = { MediaStore.Images.Media._ID,
MediaStore.Images.Media.DATA };
final String imageOrderBy = MediaStore.Images.Media._ID + " DESC";
Cursor imageCursor = managedQuery(
MediaStore.Images.Media.EXTERNAL_CONTENT_URI, imageColumns,
null, null, imageOrderBy);
if (imageCursor.moveToFirst()) {
int id = imageCursor.getInt(imageCursor
.getColumnIndex(MediaStore.Images.Media._ID));
String fullPath = imageCursor.getString(imageCursor
.getColumnIndex(MediaStore.Images.Media.DATA));
Log.d(getClass().getSimpleName(), "getLastImageId::id " + id);
Log.d(getClass().getSimpleName(), "getLastImageId::path "
+ fullPath);
imageCursor.close();
return id;
} else {
return 0;
}
}
在 logcat 中输出：
09-24 16:36:24.500: getLastImageId::id 70
09-24 16:36:24.500: getLastImageId::path /mnt/sdcard/DCIM/Camera/2012-09-24 16.36.20.jpg
我在上面的代码 sn-p 中也没有看到任何硬编码的名称。 希望这会有所帮助。
【讨论】：
注意：如果您使用的是 android 6.0 或更高版本，路径将给出 null 值。
所以你必须添加权限
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
public void onClicked(View view){
Bitmap bitmap=getBitmapFromView(scrollView,scrollView.getChildAt(0).getHeight(),scrollView.getChildAt(0).getWidth());
ByteArrayOutputStream baos = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG,90,baos);
String path = MediaStore.Images.Media.insertImage(getContentResolver(),bitmap,"title",null);
Intent intent = new Intent(Intent.ACTION_SEND);
intent.setType("image/jpeg");
intent.putExtra(Intent.EXTRA_STREAM,Uri.parse(path));
startActivity(Intent.createChooser(intent,"Share Screenshot Using"));
}
【讨论】：
尝试使用以下代码。可能对你有帮助：
new AsyncTask<Void, Integer, Void>() {
protected void onPreExecute() {
};
@Override
protected Void doInBackground(Void... arg0) {
imageAdapter.images.clear();
initializeVideoAndImage();
return null;
}
protected void onProgressUpdate(Integer... integers) {
imageAdapter.notifyDataSetChanged();
}
public void initializeVideoAndImage() {
final String[] columns = { MediaStore.Images.Media.DATA, MediaStore.Images.Thumbnails._ID };
String orderBy = MediaStore.Images.Media._ID;
Cursor imageCursor = managedQuery(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, columns, null, null, orderBy);
final String[] videocolumns = { MediaStore.Video.Thumbnails._ID, MediaStore.Video.Media.DATA };
orderBy = MediaStore.Video.Media._ID;
Cursor videoCursor = managedQuery(MediaStore.Video.Media.EXTERNAL_CONTENT_URI, videocolumns, null, null, orderBy);
int i = 0;
int image_column_index = 0;
if (imageCursor != null) {
image_column_index = imageCursor.getColumnIndex(MediaStore.Images.Media._ID);
int count = imageCursor.getCount();
for (i = 0; i < count; i++) {
imageCursor.moveToPosition(i);
int id = imageCursor.getInt(image_column_index);
ImageItem imageItem = new ImageItem();
imageItem.id = id;
imageAdapter.images.add(imageItem);
}
}
if (videoCursor != null) {
image_column_index = videoCursor.getColumnIndex(MediaStore.Video.Media._ID);
int count = videoCursor.getCount();
for (i = 0; i < count; i++) {
videoCursor.moveToPosition(i);
int id = videoCursor.getInt(image_column_index);
ImageItem imageItem = new ImageItem();
imageItem.id = id;
imageAdapter.images.add(imageItem);
}
}
publishProgress(i);
if (imageCursor != null) {
image_column_index = imageCursor.getColumnIndex(MediaStore.Images.Media._ID);
int count = imageCursor.getCount();
for (i = 0; i < count; i++) {
imageCursor.moveToPosition(i);
int id = imageCursor.getInt(image_column_index);
int dataColumnIndex = imageCursor.getColumnIndex(MediaStore.Images.Media.DATA);
ImageItem imageItem = imageAdapter.images.get(i);
Bitmap img = MediaStore.Images.Thumbnails.getThumbnail(getApplicationContext().getContentResolver(), id, MediaStore.Images.Thumbnails.MICRO_KIND, null);
int column_index = imageCursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
imageItem.imagePath = imageCursor.getString(column_index);
imageItem.videoPath = "";
try {
File imageFile = new File(Environment.getExternalStorageDirectory(), "image" + i);
imageFile.createNewFile();
ByteArrayOutputStream bos = new ByteArrayOutputStream();
if (bos != null && img != null) {
img.compress(Bitmap.CompressFormat.PNG, 100, bos);
}
byte[] bitmapData = bos.toByteArray();
FileOutputStream fos = new FileOutputStream(imageFile);
fos.write(bitmapData);
fos.close();
imageItem.thumbNailPath = imageFile.getAbsolutePath();
try {
boolean cancelled = isCancelled();
// if async task is not cancelled, update the
// progress
if (!cancelled) {
publishProgress(i);
SystemClock.sleep(100);
}
} catch (Exception e) {
Log.e("Error", e.toString());
}
// publishProgress();
} catch (IOException e) {
e.printStackTrace();
}
// imageAdapter.images.add(imageItem);
}
}
imageCursor.close();
if (videoCursor != null) {
image_column_index = videoCursor.getColumnIndex(MediaStore.Video.Media._ID);
int count = videoCursor.getCount() + i;
for (int j = 0; i < count; i++, j++) {
videoCursor.moveToPosition(j);
int id = videoCursor.getInt(image_column_index);
int column_index = videoCursor.getColumnIndexOrThrow(MediaStore.Video.Media.DATA);
ImageItem imageItem = imageAdapter.images.get(i);
imageItem.imagePath = videoCursor.getString(column_index);
imageItem.videoPath = imageItem.imagePath;
System.out.println("External : " + imageItem.videoPath);
try {
File imageFile = new File(Environment.getExternalStorageDirectory(), "imageV" + i);
imageFile.createNewFile();
ByteArrayOutputStream bos = new ByteArrayOutputStream();
MediaMetadataRetriever mediaVideo = new MediaMetadataRetriever();
mediaVideo.setDataSource(imageItem.videoPath);
Bitmap videoFiles = mediaVideo.getFrameAtTime();
videoFiles = ThumbnailUtils.extractThumbnail(videoFiles, 96, 96);
if (bos != null && videoFiles != null) {
videoFiles.compress(Bitmap.CompressFormat.JPEG, 100, bos);
}
byte[] bitmapData = bos.toByteArray();
FileOutputStream fos = new FileOutputStream(imageFile);
fos.write(bitmapData);
fos.close();
imageItem.imagePath = imageFile.getAbsolutePath();
imageItem.thumbNailPath = imageFile.getAbsolutePath();
try {
boolean cancelled = isCancelled();
// if async task is not cancelled, update the
// progress
if (!cancelled) {
publishProgress(i);
SystemClock.sleep(100);
}
} catch (Exception e) {
Log.e("Error", e.toString());
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
videoCursor.close();
}
protected void onPostExecute(Void result) {
imageAdapter.notifyDataSetChanged();
};
}.execute();
}
【讨论】：