如何使用 MediaStore 在 AndroidQ 中保存图像？
How to save an image in Android Q using MediaStore?
这里有个link给新的Android问Scoped Storage.
根据this Android Developers Best Practices Blog, storing shared media files (which is my case) should be done using the MediaStore API.
深入研究文档，我找不到相关函数。
这是我在 Kotlin 中的试用：
val bitmap = getImageBitmap() // I have a bitmap from a function or callback or whatever
val name = "example.png" // I have a name
val picturesDirectory = getExternalFilesDir(Environment.DIRECTORY_PICTURES)!!
// Make sure the directory "Android/data/com.mypackage.etc/files/Pictures" exists
if (!picturesDirectory.exists()) {
picturesDirectory.mkdirs()
}
try {
val out = FileOutputStream(File(picturesDirectory, name))
bitmap.compress(Bitmap.CompressFormat.PNG, 100, out)
out.flush()
out.close()
} catch(e: Exception) {
// handle the error
}
结果是我的图片保存在这里 Android/data/com.mypackage.etc/files/Pictures/example.png 正如最佳实践博客中描述的 Storing app-internal files
我的问题是：
如何使用 MediaStore 保存图片API？
Java 中的答案同样可以接受。
提前致谢！
编辑
感谢 PerracoLabs
这真的很有帮助！
不过还有3分
这是我的代码：
val name = "Myimage"
val relativeLocation = Environment.DIRECTORY_PICTURES + File.pathSeparator + "AppName"
val contentValues = ContentValues().apply {
put(MediaStore.Images.ImageColumns.DISPLAY_NAME, name)
put(MediaStore.MediaColumns.MIME_TYPE, "image/png")
// without this part causes "Failed to create new MediaStore record" exception to be invoked (uri is null below)
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
put(MediaStore.Images.ImageColumns.RELATIVE_PATH, relativeLocation)
}
}
val contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI
var stream: OutputStream? = null
var uri: Uri? = null
try {
uri = contentResolver.insert(contentUri, contentValues)
if (uri == null)
{
throw IOException("Failed to create new MediaStore record.")
}
stream = contentResolver.openOutputStream(uri)
if (stream == null)
{
throw IOException("Failed to get output stream.")
}
if (!bitmap.compress(Bitmap.CompressFormat.PNG, 100, stream))
{
throw IOException("Failed to save bitmap.")
}
Snackbar.make(mCoordinator, R.string.image_saved_success, Snackbar.LENGTH_INDEFINITE).setAction("Open") {
val intent = Intent()
intent.type = "image/*"
intent.action = Intent.ACTION_VIEW
intent.data = contentUri
startActivity(Intent.createChooser(intent, "Select Gallery App"))
}.show()
} catch(e: IOException) {
if (uri != null)
{
contentResolver.delete(uri, null, null)
}
throw IOException(e)
}
finally {
stream?.close()
}
1- 保存的图像没有得到正确的名称"Myimage.png"
我尝试使用 "Myimage" 和 "Myimage.PNG" 但都没有用。
图片的名称总是由数字组成，例如：
1563468625314.jpg
这给我们带来了第二个问题：
2- 即使我以 png.
格式压缩位图，图像仍保存为 jpg
问题不大。只是好奇为什么。
3- relativeLocation 位在小于 Android Q 的设备上导致异常。
在用 "Android Version Check" if 语句包围后，图像直接保存在 Pictures 文件夹的根目录中。
再次感谢。
编辑 2
更改为：
uri = contentResolver.insert(contentUri, contentValues)
if (uri == null)
{
throw IOException("Failed to create new MediaStore record.")
}
val cursor = contentResolver.query(uri, null, null, null, null)
DatabaseUtils.dumpCursor(cursor)
cursor!!.close()
stream = contentResolver.openOutputStream(uri)
这是日志
I/System.out: >>>>> Dumping cursor android.content.ContentResolver$CursorWrapperInner@76da9d1
I/System.out: 0 {
I/System.out: _id=25417
I/System.out: _data=/storage/emulated/0/Pictures/1563640732667.jpg
I/System.out: _size=null
I/System.out: _display_name=Myimage
I/System.out: mime_type=image/png
I/System.out: title=1563640732667
I/System.out: date_added=1563640732
I/System.out: is_hdr=null
I/System.out: date_modified=null
I/System.out: description=null
I/System.out: picasa_id=null
I/System.out: isprivate=null
I/System.out: latitude=null
I/System.out: longitude=null
I/System.out: datetaken=null
I/System.out: orientation=null
I/System.out: mini_thumb_magic=null
I/System.out: bucket_id=-1617409521
I/System.out: bucket_display_name=Pictures
I/System.out: width=null
I/System.out: height=null
I/System.out: is_hw_privacy=null
I/System.out: hw_voice_offset=null
I/System.out: is_hw_favorite=null
I/System.out: hw_image_refocus=null
I/System.out: album_sort_index=null
I/System.out: bucket_display_name_alias=null
I/System.out: is_hw_burst=0
I/System.out: hw_rectify_offset=null
I/System.out: special_file_type=0
I/System.out: special_file_offset=null
I/System.out: cam_perception=null
I/System.out: cam_exif_flag=null
I/System.out: }
I/System.out: <<<<<
我注意到 title 与名称匹配，所以我尝试添加：
put(MediaStore.Images.ImageColumns.TITLE, name)
它仍然无效，这是新日志：
I/System.out: >>>>> Dumping cursor android.content.ContentResolver$CursorWrapperInner@51021a5
I/System.out: 0 {
I/System.out: _id=25418
I/System.out: _data=/storage/emulated/0/Pictures/1563640934803.jpg
I/System.out: _size=null
I/System.out: _display_name=Myimage
I/System.out: mime_type=image/png
I/System.out: title=Myimage
I/System.out: date_added=1563640934
I/System.out: is_hdr=null
I/System.out: date_modified=null
I/System.out: description=null
I/System.out: picasa_id=null
I/System.out: isprivate=null
I/System.out: latitude=null
I/System.out: longitude=null
I/System.out: datetaken=null
I/System.out: orientation=null
I/System.out: mini_thumb_magic=null
I/System.out: bucket_id=-1617409521
I/System.out: bucket_display_name=Pictures
I/System.out: width=null
I/System.out: height=null
I/System.out: is_hw_privacy=null
I/System.out: hw_voice_offset=null
I/System.out: is_hw_favorite=null
I/System.out: hw_image_refocus=null
I/System.out: album_sort_index=null
I/System.out: bucket_display_name_alias=null
I/System.out: is_hw_burst=0
I/System.out: hw_rectify_offset=null
I/System.out: special_file_type=0
I/System.out: special_file_offset=null
I/System.out: cam_perception=null
I/System.out: cam_exif_flag=null
I/System.out: }
I/System.out: <<<<<
而且我无法将 date_added 更改为名称。
并且 MediaStore.MediaColumns.DATA 已弃用。
提前致谢！
试试下一个方法。 Android Q（及以上）已经负责创建文件夹（如果它们不存在）。例子是hard-coded输出到DCIM文件夹。如果您需要 sub-folder，则将 sub-folder 名称附加为下一个：
final String relativeLocation = Environment.DIRECTORY_DCIM + File.separator + “YourSubforderName”;
考虑压缩格式应该与mime-type参数有关。例如，对于 JPEG 压缩格式，mime-type 将是“image/jpeg”，依此类推。可能您还想将压缩质量作为参数传递，在此示例中硬编码为 95。
Java:
@NonNull
public Uri saveBitmap(@NonNull final Context context, @NonNull final Bitmap bitmap,
@NonNull final Bitmap.CompressFormat format,
@NonNull final String mimeType,
@NonNull final String displayName) throws IOException {
final ContentValues values = new ContentValues();
values.put(MediaStore.MediaColumns.DISPLAY_NAME, displayName);
values.put(MediaStore.MediaColumns.MIME_TYPE, mimeType);
values.put(MediaStore.MediaColumns.RELATIVE_PATH, Environment.DIRECTORY_DCIM);
final ContentResolver resolver = context.getContentResolver();
Uri uri = null;
try {
final Uri contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
uri = resolver.insert(contentUri, values);
if (uri == null)
throw new IOException("Failed to create new MediaStore record.");
try (final OutputStream stream = resolver.openOutputStream(uri)) {
if (stream == null)
throw new IOException("Failed to open output stream.");
if (!bitmap.compress(format, 95, stream))
throw new IOException("Failed to save bitmap.");
}
return uri;
}
catch (IOException e) {
if (uri != null) {
// Don't leave an orphan entry in the MediaStore
resolver.delete(uri, null, null);
}
throw e;
}
}
科特林：
@Throws(IOException::class)
fun saveBitmap(
context: Context, bitmap: Bitmap, format: Bitmap.CompressFormat,
mimeType: String, displayName: String
): Uri {
val values = ContentValues().apply {
put(MediaStore.MediaColumns.DISPLAY_NAME, displayName)
put(MediaStore.MediaColumns.MIME_TYPE, mimeType)
put(MediaStore.MediaColumns.RELATIVE_PATH, Environment.DIRECTORY_DCIM)
}
val resolver = context.contentResolver
var uri: Uri? = null
try {
uri = resolver.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values)
?: throw IOException("Failed to create new MediaStore record.")
resolver.openOutputStream(uri)?.use {
if (!bitmap.compress(format, 95, it))
throw IOException("Failed to save bitmap.")
} ?: throw IOException("Failed to open output stream.")
return uri
} catch (e: IOException) {
uri?.let { orphanUri ->
// Don't leave an orphan entry in the MediaStore
resolver.delete(orphanUri, null, null)
}
throw e
}
}
Kotlin 变体，具有更实用的风格：
@Throws(IOException::class)
fun saveBitmap(
context: Context, bitmap: Bitmap, format: Bitmap.CompressFormat,
mimeType: String, displayName: String
): Uri {
val values = ContentValues().apply {
put(MediaStore.MediaColumns.DISPLAY_NAME, displayName)
put(MediaStore.MediaColumns.MIME_TYPE, mimeType)
put(MediaStore.MediaColumns.RELATIVE_PATH, Environment.DIRECTORY_DCIM)
}
var uri: Uri? = null
return runCatching {
with(context.contentResolver) {
insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values)?.also {
uri = it // Keep uri reference so it can be removed on failure
openOutputStream(it)?.use { stream ->
if (!bitmap.compress(format, 95, stream))
throw IOException("Failed to save bitmap.")
} ?: throw IOException("Failed to open output stream.")
} ?: throw IOException("Failed to create new MediaStore record.")
}
}.getOrElse {
uri?.let { orphanUri ->
// Don't leave an orphan entry in the MediaStore
context.contentResolver.delete(orphanUri, null, null)
}
throw it
}
}
private void saveImage(Bitmap bitmap, @NonNull String name) throws IOException {
OutputStream fos;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
ContentResolver resolver = getContentResolver();
ContentValues contentValues = new ContentValues();
contentValues.put(MediaStore.MediaColumns.DISPLAY_NAME, name + ".jpg");
contentValues.put(MediaStore.MediaColumns.MIME_TYPE, "image/jpg");
contentValues.put(MediaStore.MediaColumns.RELATIVE_PATH, Environment.DIRECTORY_PICTURES);
Uri imageUri = resolver.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, contentValues);
fos = resolver.openOutputStream(Objects.requireNonNull(imageUri));
} else {
String imagesDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).toString();
File image = new File(imagesDir, name + ".jpg");
fos = new FileOutputStream(image);
}
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);
Objects.requireNonNull(fos).close();
}
图像将存储在图片文件夹@根级别
实时查看https://youtu.be/695HqaiwzQ0我创建了教程
这是我一直使用的。你可以试试。
private void saveImageToStorage() throws IOException {
OutputStream imageOutStream;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
ContentValues values = new ContentValues();
values.put(MediaStore.Images.Media.DISPLAY_NAME, "image_screenshot.jpg");
values.put(MediaStore.Images.Media.MIME_TYPE, "image/jpeg");
values.put(MediaStore.Images.Media.RELATIVE_PATH, Environment.DIRECTORY_PICTURES);
Uri uri = getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
imageOutStream = getContentResolver().openOutputStream(uri);
} else {
String imagePath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).toString();
File image = new File(imagePath, "image_screenshotjpg");
imageOutStream = new FileOutputStream(image);
}
try {
bitmapObject.compress(Bitmap.CompressFormat.JPEG, 100, imageOutStream);
} finally {
imageOutStream.close();
}
}
如果有人在寻找如何将照片保存到 DCIM 文件夹中，以一种稍后会出现在 Google 照片中的方式：
（基于：https://github.com/yasirkula/UnityNativeGallery/blob/670d9e2b8328f7796dd95d29dd80fadd8935b804/JAR%20Source/NativeGallery.java#L73-L96）
ContentValue values = new ContentValues();
values.put(MediaStore.MediaColumns.RELATIVE_PATH, Environment.DIRECTORY_DCIM);
values.put(MediaStore.MediaColumns.DATE_TAKEN, System.currentTimeMillis());
values.put(MediaStore.MediaColumns.IS_PENDING, true);
Uri uri = context.getContentResolver().insert(externalContentUri, values);
if (uri != null) {
try {
if (WriteFileToStream(originalFile, context.getContentResolver().openOutputStream(uri))) {
values.put(MediaStore.MediaColumns.IS_PENDING, false);
context.getContentResolver().update(uri, values, null, null);
}
} catch (Exception e) {
context.getContentResolver().delete( uri, null, null );
}
}
其中 WriteFileToStream 是从文件复制到流的标准方法。
这是我的 2022 版本，此版本在 Emulator SDK 27 和 30 中也在三星 S22 上进行了测试 Phone。
TL:DR
SDK < 29 需要遵循代码here，成功拍照后几乎不需要添加代码。您可以在下面的 savePictureQ(...) 函数中看到
否则，如果您的 SDK >= 29，只需在 MediaStore.EXTRA_OUTPUT extras from contentResolver.insert(...) function
处传递 URI
因为 startActivityForResult(Intent) 已经使用 registerForActivityResult(...)
弃用了我的版本
private val cameraLauncher =
registerForActivityResult(ActivityResultContracts.StartActivityForResult()) {
if (it.resultCode == Activity.RESULT_OK) {
val name: String = viewModel.savePictureQ()
if (name != "") requireActivity().applicationContext.deleteFile(name)
val cr = requireContext().contentResolver
val uri = viewModel.getTargetUri()
if (uri != null) {
val bitmap = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
val source = ImageDecoder.createSource(cr, uri)
ImageDecoder.decodeBitmap(source)
} else MediaStore.Images.Media.getBitmap(cr, uri)
val resized = Bitmap.createScaledBitmap(bitmap, 512, 512, true)
}
}
}
我在另一个名为 Repository.kt 的文件中调用 Intent，我还使用伪造的 viewModel 来调用 Repository 代码。
这是我调用 viewModel 代码的方式
private lateinit var viewModel: MenuViewModel
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?
): View {
viewModel = MenuViewModel(Injection.provideRepository(requireContext()))
...
}
private fun permissionCheck() {
val granted = PackageManager.PERMISSION_GRANTED
val permissions = arrayOf(
Manifest.permission.WRITE_EXTERNAL_STORAGE,
Manifest.permission.READ_EXTERNAL_STORAGE,
Manifest.permission.CAMERA
)
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {
if (ActivityCompat.checkSelfPermission(
requireContext(),
permissions[0]
) != granted && ActivityCompat.checkSelfPermission(
requireContext(),
permissions[1]
) != granted && ActivityCompat.checkSelfPermission(
requireContext(),
permissions[2]
) != granted
) ActivityCompat.requestPermissions(
requireActivity(), permissions, MainActivity.REQUEST_CODE_PERMISSION
) else MainActivity.accepted = true
} else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
if (ActivityCompat.checkSelfPermission(
requireContext(),
permissions[2]
) != granted && ActivityCompat.checkSelfPermission(
requireContext(),
Manifest.permission.ACCESS_MEDIA_LOCATION
) != granted
) ActivityCompat.requestPermissions(
requireActivity(),
arrayOf(permissions[2], Manifest.permission.ACCESS_MEDIA_LOCATION),
MainActivity.REQUEST_CODE_PERMISSION
) else MainActivity.accepted = true
}
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
...
bind.fromCamera.setOnClickListener {
permissionCheck()
if (`permission granted check`) {
viewModel.getCameraIntent(cameraLauncher)
}
}
...
}
在我的假 viewModel 中：
class MenuViewModel(private val repository: IRepository) {
fun getTargetUri() = repository.getTargetUri()
fun getCameraIntent(launcher: ActivityResultLauncher<Intent>) =
repository.createTakePictureIntent(launcher)
fun savePictureQ(): String = repository.savePictureQ()
}
在我的存储库代码中：
class Repository private constructor(private val context: Context) : IRepository {
companion object {
@Volatile
private var INSTANCE: IRepository? = null
fun getInstance(context: Context) = INSTANCE ?: synchronized(this) {
INSTANCE ?: Repository(context).apply { INSTANCE = this }
}
}
private var currentPath = ""
private var targetUri: Uri? = null
private fun createImageFile(): File { // create temporary file for SDK < 29
val timestamp = SimpleDateFormat("yyyyMMdd_HHmmss", Locale.getDefault()).format(Date())
val storageDir = context.getExternalFilesDir(Environment.DIRECTORY_PICTURES)
return File.createTempFile(timestamp, ".jpg", storageDir)
.apply { currentPath = absolutePath }
}
override fun savePictureQ() : String { // Saving picture and added to Gallery for SDK < 29
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {
val f = File(currentPath)
val cr = context.contentResolver
val bitmap = BitmapFactory.decodeFile(currentPath)
val path = "${Environment.DIRECTORY_PICTURES}${File.separator}PoCkDetection"
val values = createContentValues(f.name, path)
var uri: Uri? = null
try {
uri = cr.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values)!!
val os = cr.openOutputStream(uri)
try {
val result = bitmap.compress(Bitmap.CompressFormat.JPEG, 100, os)
if (!result) throw Exception()
} catch (e: Exception) {
e.printStackTrace()
throw e
} finally {
os?.close()
targetUri = uri
}
f.delete()
if (f.exists()) {
f.canonicalFile.delete()
if (f.exists()) return f.name
}
} catch (e: Exception) {
e.printStackTrace()
uri?.let {
cr.delete(it, null, null)
}
}
}
return ""
}
override fun getTargetUri(): Uri? = targetUri
private fun createContentValues(title: String, path: String): ContentValues =
ContentValues().apply {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
put(MediaStore.MediaColumns.TITLE, "$title.jpg")
put(MediaStore.MediaColumns.DISPLAY_NAME, "$title.jpg")
put(MediaStore.MediaColumns.MIME_TYPE, "image/jpg")
put(MediaStore.MediaColumns.DATE_ADDED, System.currentTimeMillis())
put(MediaStore.MediaColumns.DATE_TAKEN, System.currentTimeMillis())
put(MediaStore.MediaColumns.RELATIVE_PATH, path)
} else {
put(MediaStore.Images.Media.TITLE, "$title.jpg")
put(MediaStore.Images.Media.DISPLAY_NAME, "$title.jpg")
put(MediaStore.Images.Media.MIME_TYPE, "image/jpg")
put(MediaStore.Images.Media.DATE_ADDED, System.currentTimeMillis())
put(MediaStore.Images.Media.DATE_TAKEN, System.currentTimeMillis())
}
}
override fun createTakePictureIntent(launcher: ActivityResultLauncher<Intent>) {
Intent(MediaStore.ACTION_IMAGE_CAPTURE).also { takePictureIntent ->
takePictureIntent.resolveActivity(context.packageManager).also {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {
val photoFile: File? = try {
createImageFile()
} catch (e: IOException) {
e.printStackTrace()
null
}
photoFile?.also {
val photoURI =
FileProvider.getUriForFile(context, "com.your.package.name", it)
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI)
launcher.launch(takePictureIntent)
}
} else {
val timestamp =
SimpleDateFormat("yyyyMMdd_HHmmss", Locale.getDefault()).format(Date())
val path = "${Environment.DIRECTORY_PICTURES}${File.separator}PoCkDetection"
val values = createContentValues(timestamp, path)
val photoURI = context.contentResolver.insert(
MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values
)
targetUri = photoURI
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI)
launcher.launch(takePictureIntent)
}
}
}
}
}
对于 SDK < 29，我遵循 Google Developer
中的代码
这是我的清单在遵循代码后的样子：
<application ...>
<provider
android:name="androidx.core.content.FileProvider"
android:authorities="com.your.package.name"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/camera_paths" />
</provider>
</application>
创建名为 xml 的新 res 文件夹，然后创建新的 xml 文件，确保名称与您放置在 <provider> 中的 <meta-data> 和该文件中的名称相同：
<?xml version="1.0" encoding="utf-8"?>
<paths>
<external-files-path
name="camera_take"
path="Pictures" />
</paths>
这里有个link给新的Android问Scoped Storage.
根据this Android Developers Best Practices Blog, storing shared media files (which is my case) should be done using the MediaStore API.
深入研究文档，我找不到相关函数。
这是我在 Kotlin 中的试用：
val bitmap = getImageBitmap() // I have a bitmap from a function or callback or whatever
val name = "example.png" // I have a name
val picturesDirectory = getExternalFilesDir(Environment.DIRECTORY_PICTURES)!!
// Make sure the directory "Android/data/com.mypackage.etc/files/Pictures" exists
if (!picturesDirectory.exists()) {
picturesDirectory.mkdirs()
}
try {
val out = FileOutputStream(File(picturesDirectory, name))
bitmap.compress(Bitmap.CompressFormat.PNG, 100, out)
out.flush()
out.close()
} catch(e: Exception) {
// handle the error
}
结果是我的图片保存在这里 Android/data/com.mypackage.etc/files/Pictures/example.png 正如最佳实践博客中描述的 Storing app-internal files
我的问题是：
如何使用 MediaStore 保存图片API？
Java 中的答案同样可以接受。
提前致谢！
编辑
感谢 PerracoLabs
这真的很有帮助！
不过还有3分
这是我的代码：
val name = "Myimage"
val relativeLocation = Environment.DIRECTORY_PICTURES + File.pathSeparator + "AppName"
val contentValues = ContentValues().apply {
put(MediaStore.Images.ImageColumns.DISPLAY_NAME, name)
put(MediaStore.MediaColumns.MIME_TYPE, "image/png")
// without this part causes "Failed to create new MediaStore record" exception to be invoked (uri is null below)
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
put(MediaStore.Images.ImageColumns.RELATIVE_PATH, relativeLocation)
}
}
val contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI
var stream: OutputStream? = null
var uri: Uri? = null
try {
uri = contentResolver.insert(contentUri, contentValues)
if (uri == null)
{
throw IOException("Failed to create new MediaStore record.")
}
stream = contentResolver.openOutputStream(uri)
if (stream == null)
{
throw IOException("Failed to get output stream.")
}
if (!bitmap.compress(Bitmap.CompressFormat.PNG, 100, stream))
{
throw IOException("Failed to save bitmap.")
}
Snackbar.make(mCoordinator, R.string.image_saved_success, Snackbar.LENGTH_INDEFINITE).setAction("Open") {
val intent = Intent()
intent.type = "image/*"
intent.action = Intent.ACTION_VIEW
intent.data = contentUri
startActivity(Intent.createChooser(intent, "Select Gallery App"))
}.show()
} catch(e: IOException) {
if (uri != null)
{
contentResolver.delete(uri, null, null)
}
throw IOException(e)
}
finally {
stream?.close()
}
1- 保存的图像没有得到正确的名称"Myimage.png"
我尝试使用 "Myimage" 和 "Myimage.PNG" 但都没有用。
图片的名称总是由数字组成，例如：
1563468625314.jpg
这给我们带来了第二个问题：
2- 即使我以 png.
jpg
问题不大。只是好奇为什么。
3- relativeLocation 位在小于 Android Q 的设备上导致异常。
在用 "Android Version Check" if 语句包围后，图像直接保存在 Pictures 文件夹的根目录中。
再次感谢。
编辑 2
更改为：
uri = contentResolver.insert(contentUri, contentValues)
if (uri == null)
{
throw IOException("Failed to create new MediaStore record.")
}
val cursor = contentResolver.query(uri, null, null, null, null)
DatabaseUtils.dumpCursor(cursor)
cursor!!.close()
stream = contentResolver.openOutputStream(uri)
这是日志
I/System.out: >>>>> Dumping cursor android.content.ContentResolver$CursorWrapperInner@76da9d1
I/System.out: 0 {
I/System.out: _id=25417
I/System.out: _data=/storage/emulated/0/Pictures/1563640732667.jpg
I/System.out: _size=null
I/System.out: _display_name=Myimage
I/System.out: mime_type=image/png
I/System.out: title=1563640732667
I/System.out: date_added=1563640732
I/System.out: is_hdr=null
I/System.out: date_modified=null
I/System.out: description=null
I/System.out: picasa_id=null
I/System.out: isprivate=null
I/System.out: latitude=null
I/System.out: longitude=null
I/System.out: datetaken=null
I/System.out: orientation=null
I/System.out: mini_thumb_magic=null
I/System.out: bucket_id=-1617409521
I/System.out: bucket_display_name=Pictures
I/System.out: width=null
I/System.out: height=null
I/System.out: is_hw_privacy=null
I/System.out: hw_voice_offset=null
I/System.out: is_hw_favorite=null
I/System.out: hw_image_refocus=null
I/System.out: album_sort_index=null
I/System.out: bucket_display_name_alias=null
I/System.out: is_hw_burst=0
I/System.out: hw_rectify_offset=null
I/System.out: special_file_type=0
I/System.out: special_file_offset=null
I/System.out: cam_perception=null
I/System.out: cam_exif_flag=null
I/System.out: }
I/System.out: <<<<<
我注意到 title 与名称匹配，所以我尝试添加：
put(MediaStore.Images.ImageColumns.TITLE, name)
它仍然无效，这是新日志：
I/System.out: >>>>> Dumping cursor android.content.ContentResolver$CursorWrapperInner@51021a5
I/System.out: 0 {
I/System.out: _id=25418
I/System.out: _data=/storage/emulated/0/Pictures/1563640934803.jpg
I/System.out: _size=null
I/System.out: _display_name=Myimage
I/System.out: mime_type=image/png
I/System.out: title=Myimage
I/System.out: date_added=1563640934
I/System.out: is_hdr=null
I/System.out: date_modified=null
I/System.out: description=null
I/System.out: picasa_id=null
I/System.out: isprivate=null
I/System.out: latitude=null
I/System.out: longitude=null
I/System.out: datetaken=null
I/System.out: orientation=null
I/System.out: mini_thumb_magic=null
I/System.out: bucket_id=-1617409521
I/System.out: bucket_display_name=Pictures
I/System.out: width=null
I/System.out: height=null
I/System.out: is_hw_privacy=null
I/System.out: hw_voice_offset=null
I/System.out: is_hw_favorite=null
I/System.out: hw_image_refocus=null
I/System.out: album_sort_index=null
I/System.out: bucket_display_name_alias=null
I/System.out: is_hw_burst=0
I/System.out: hw_rectify_offset=null
I/System.out: special_file_type=0
I/System.out: special_file_offset=null
I/System.out: cam_perception=null
I/System.out: cam_exif_flag=null
I/System.out: }
I/System.out: <<<<<
而且我无法将 date_added 更改为名称。
并且 MediaStore.MediaColumns.DATA 已弃用。
提前致谢！
试试下一个方法。 Android Q（及以上）已经负责创建文件夹（如果它们不存在）。例子是hard-coded输出到DCIM文件夹。如果您需要 sub-folder，则将 sub-folder 名称附加为下一个：
final String relativeLocation = Environment.DIRECTORY_DCIM + File.separator + “YourSubforderName”;
考虑压缩格式应该与mime-type参数有关。例如，对于 JPEG 压缩格式，mime-type 将是“image/jpeg”，依此类推。可能您还想将压缩质量作为参数传递，在此示例中硬编码为 95。
Java:
@NonNull
public Uri saveBitmap(@NonNull final Context context, @NonNull final Bitmap bitmap,
@NonNull final Bitmap.CompressFormat format,
@NonNull final String mimeType,
@NonNull final String displayName) throws IOException {
final ContentValues values = new ContentValues();
values.put(MediaStore.MediaColumns.DISPLAY_NAME, displayName);
values.put(MediaStore.MediaColumns.MIME_TYPE, mimeType);
values.put(MediaStore.MediaColumns.RELATIVE_PATH, Environment.DIRECTORY_DCIM);
final ContentResolver resolver = context.getContentResolver();
Uri uri = null;
try {
final Uri contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
uri = resolver.insert(contentUri, values);
if (uri == null)
throw new IOException("Failed to create new MediaStore record.");
try (final OutputStream stream = resolver.openOutputStream(uri)) {
if (stream == null)
throw new IOException("Failed to open output stream.");
if (!bitmap.compress(format, 95, stream))
throw new IOException("Failed to save bitmap.");
}
return uri;
}
catch (IOException e) {
if (uri != null) {
// Don't leave an orphan entry in the MediaStore
resolver.delete(uri, null, null);
}
throw e;
}
}
科特林：
@Throws(IOException::class)
fun saveBitmap(
context: Context, bitmap: Bitmap, format: Bitmap.CompressFormat,
mimeType: String, displayName: String
): Uri {
val values = ContentValues().apply {
put(MediaStore.MediaColumns.DISPLAY_NAME, displayName)
put(MediaStore.MediaColumns.MIME_TYPE, mimeType)
put(MediaStore.MediaColumns.RELATIVE_PATH, Environment.DIRECTORY_DCIM)
}
val resolver = context.contentResolver
var uri: Uri? = null
try {
uri = resolver.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values)
?: throw IOException("Failed to create new MediaStore record.")
resolver.openOutputStream(uri)?.use {
if (!bitmap.compress(format, 95, it))
throw IOException("Failed to save bitmap.")
} ?: throw IOException("Failed to open output stream.")
return uri
} catch (e: IOException) {
uri?.let { orphanUri ->
// Don't leave an orphan entry in the MediaStore
resolver.delete(orphanUri, null, null)
}
throw e
}
}
Kotlin 变体，具有更实用的风格：
@Throws(IOException::class)
fun saveBitmap(
context: Context, bitmap: Bitmap, format: Bitmap.CompressFormat,
mimeType: String, displayName: String
): Uri {
val values = ContentValues().apply {
put(MediaStore.MediaColumns.DISPLAY_NAME, displayName)
put(MediaStore.MediaColumns.MIME_TYPE, mimeType)
put(MediaStore.MediaColumns.RELATIVE_PATH, Environment.DIRECTORY_DCIM)
}
var uri: Uri? = null
return runCatching {
with(context.contentResolver) {
insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values)?.also {
uri = it // Keep uri reference so it can be removed on failure
openOutputStream(it)?.use { stream ->
if (!bitmap.compress(format, 95, stream))
throw IOException("Failed to save bitmap.")
} ?: throw IOException("Failed to open output stream.")
} ?: throw IOException("Failed to create new MediaStore record.")
}
}.getOrElse {
uri?.let { orphanUri ->
// Don't leave an orphan entry in the MediaStore
context.contentResolver.delete(orphanUri, null, null)
}
throw it
}
}
private void saveImage(Bitmap bitmap, @NonNull String name) throws IOException {
OutputStream fos;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
ContentResolver resolver = getContentResolver();
ContentValues contentValues = new ContentValues();
contentValues.put(MediaStore.MediaColumns.DISPLAY_NAME, name + ".jpg");
contentValues.put(MediaStore.MediaColumns.MIME_TYPE, "image/jpg");
contentValues.put(MediaStore.MediaColumns.RELATIVE_PATH, Environment.DIRECTORY_PICTURES);
Uri imageUri = resolver.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, contentValues);
fos = resolver.openOutputStream(Objects.requireNonNull(imageUri));
} else {
String imagesDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).toString();
File image = new File(imagesDir, name + ".jpg");
fos = new FileOutputStream(image);
}
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);
Objects.requireNonNull(fos).close();
}
图像将存储在图片文件夹@根级别
实时查看https://youtu.be/695HqaiwzQ0我创建了教程
这是我一直使用的。你可以试试。
private void saveImageToStorage() throws IOException {
OutputStream imageOutStream;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
ContentValues values = new ContentValues();
values.put(MediaStore.Images.Media.DISPLAY_NAME, "image_screenshot.jpg");
values.put(MediaStore.Images.Media.MIME_TYPE, "image/jpeg");
values.put(MediaStore.Images.Media.RELATIVE_PATH, Environment.DIRECTORY_PICTURES);
Uri uri = getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
imageOutStream = getContentResolver().openOutputStream(uri);
} else {
String imagePath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).toString();
File image = new File(imagePath, "image_screenshotjpg");
imageOutStream = new FileOutputStream(image);
}
try {
bitmapObject.compress(Bitmap.CompressFormat.JPEG, 100, imageOutStream);
} finally {
imageOutStream.close();
}
}
如果有人在寻找如何将照片保存到 DCIM 文件夹中，以一种稍后会出现在 Google 照片中的方式： （基于：https://github.com/yasirkula/UnityNativeGallery/blob/670d9e2b8328f7796dd95d29dd80fadd8935b804/JAR%20Source/NativeGallery.java#L73-L96）
ContentValue values = new ContentValues();
values.put(MediaStore.MediaColumns.RELATIVE_PATH, Environment.DIRECTORY_DCIM);
values.put(MediaStore.MediaColumns.DATE_TAKEN, System.currentTimeMillis());
values.put(MediaStore.MediaColumns.IS_PENDING, true);
Uri uri = context.getContentResolver().insert(externalContentUri, values);
if (uri != null) {
try {
if (WriteFileToStream(originalFile, context.getContentResolver().openOutputStream(uri))) {
values.put(MediaStore.MediaColumns.IS_PENDING, false);
context.getContentResolver().update(uri, values, null, null);
}
} catch (Exception e) {
context.getContentResolver().delete( uri, null, null );
}
}
其中 WriteFileToStream 是从文件复制到流的标准方法。
这是我的 2022 版本，此版本在 Emulator SDK 27 和 30 中也在三星 S22 上进行了测试 Phone。
TL:DR
SDK < 29 需要遵循代码here，成功拍照后几乎不需要添加代码。您可以在下面的 savePictureQ(...) 函数中看到
否则，如果您的 SDK >= 29，只需在 MediaStore.EXTRA_OUTPUT extras from contentResolver.insert(...) function
因为 startActivityForResult(Intent) 已经使用 registerForActivityResult(...)
private val cameraLauncher =
registerForActivityResult(ActivityResultContracts.StartActivityForResult()) {
if (it.resultCode == Activity.RESULT_OK) {
val name: String = viewModel.savePictureQ()
if (name != "") requireActivity().applicationContext.deleteFile(name)
val cr = requireContext().contentResolver
val uri = viewModel.getTargetUri()
if (uri != null) {
val bitmap = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
val source = ImageDecoder.createSource(cr, uri)
ImageDecoder.decodeBitmap(source)
} else MediaStore.Images.Media.getBitmap(cr, uri)
val resized = Bitmap.createScaledBitmap(bitmap, 512, 512, true)
}
}
}
我在另一个名为 Repository.kt 的文件中调用 Intent，我还使用伪造的 viewModel 来调用 Repository 代码。 这是我调用 viewModel 代码的方式
private lateinit var viewModel: MenuViewModel
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?
): View {
viewModel = MenuViewModel(Injection.provideRepository(requireContext()))
...
}
private fun permissionCheck() {
val granted = PackageManager.PERMISSION_GRANTED
val permissions = arrayOf(
Manifest.permission.WRITE_EXTERNAL_STORAGE,
Manifest.permission.READ_EXTERNAL_STORAGE,
Manifest.permission.CAMERA
)
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {
if (ActivityCompat.checkSelfPermission(
requireContext(),
permissions[0]
) != granted && ActivityCompat.checkSelfPermission(
requireContext(),
permissions[1]
) != granted && ActivityCompat.checkSelfPermission(
requireContext(),
permissions[2]
) != granted
) ActivityCompat.requestPermissions(
requireActivity(), permissions, MainActivity.REQUEST_CODE_PERMISSION
) else MainActivity.accepted = true
} else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
if (ActivityCompat.checkSelfPermission(
requireContext(),
permissions[2]
) != granted && ActivityCompat.checkSelfPermission(
requireContext(),
Manifest.permission.ACCESS_MEDIA_LOCATION
) != granted
) ActivityCompat.requestPermissions(
requireActivity(),
arrayOf(permissions[2], Manifest.permission.ACCESS_MEDIA_LOCATION),
MainActivity.REQUEST_CODE_PERMISSION
) else MainActivity.accepted = true
}
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
...
bind.fromCamera.setOnClickListener {
permissionCheck()
if (`permission granted check`) {
viewModel.getCameraIntent(cameraLauncher)
}
}
...
}
在我的假 viewModel 中：
class MenuViewModel(private val repository: IRepository) {
fun getTargetUri() = repository.getTargetUri()
fun getCameraIntent(launcher: ActivityResultLauncher<Intent>) =
repository.createTakePictureIntent(launcher)
fun savePictureQ(): String = repository.savePictureQ()
}
在我的存储库代码中：
class Repository private constructor(private val context: Context) : IRepository {
companion object {
@Volatile
private var INSTANCE: IRepository? = null
fun getInstance(context: Context) = INSTANCE ?: synchronized(this) {
INSTANCE ?: Repository(context).apply { INSTANCE = this }
}
}
private var currentPath = ""
private var targetUri: Uri? = null
private fun createImageFile(): File { // create temporary file for SDK < 29
val timestamp = SimpleDateFormat("yyyyMMdd_HHmmss", Locale.getDefault()).format(Date())
val storageDir = context.getExternalFilesDir(Environment.DIRECTORY_PICTURES)
return File.createTempFile(timestamp, ".jpg", storageDir)
.apply { currentPath = absolutePath }
}
override fun savePictureQ() : String { // Saving picture and added to Gallery for SDK < 29
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {
val f = File(currentPath)
val cr = context.contentResolver
val bitmap = BitmapFactory.decodeFile(currentPath)
val path = "${Environment.DIRECTORY_PICTURES}${File.separator}PoCkDetection"
val values = createContentValues(f.name, path)
var uri: Uri? = null
try {
uri = cr.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values)!!
val os = cr.openOutputStream(uri)
try {
val result = bitmap.compress(Bitmap.CompressFormat.JPEG, 100, os)
if (!result) throw Exception()
} catch (e: Exception) {
e.printStackTrace()
throw e
} finally {
os?.close()
targetUri = uri
}
f.delete()
if (f.exists()) {
f.canonicalFile.delete()
if (f.exists()) return f.name
}
} catch (e: Exception) {
e.printStackTrace()
uri?.let {
cr.delete(it, null, null)
}
}
}
return ""
}
override fun getTargetUri(): Uri? = targetUri
private fun createContentValues(title: String, path: String): ContentValues =
ContentValues().apply {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
put(MediaStore.MediaColumns.TITLE, "$title.jpg")
put(MediaStore.MediaColumns.DISPLAY_NAME, "$title.jpg")
put(MediaStore.MediaColumns.MIME_TYPE, "image/jpg")
put(MediaStore.MediaColumns.DATE_ADDED, System.currentTimeMillis())
put(MediaStore.MediaColumns.DATE_TAKEN, System.currentTimeMillis())
put(MediaStore.MediaColumns.RELATIVE_PATH, path)
} else {
put(MediaStore.Images.Media.TITLE, "$title.jpg")
put(MediaStore.Images.Media.DISPLAY_NAME, "$title.jpg")
put(MediaStore.Images.Media.MIME_TYPE, "image/jpg")
put(MediaStore.Images.Media.DATE_ADDED, System.currentTimeMillis())
put(MediaStore.Images.Media.DATE_TAKEN, System.currentTimeMillis())
}
}
override fun createTakePictureIntent(launcher: ActivityResultLauncher<Intent>) {
Intent(MediaStore.ACTION_IMAGE_CAPTURE).also { takePictureIntent ->
takePictureIntent.resolveActivity(context.packageManager).also {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {
val photoFile: File? = try {
createImageFile()
} catch (e: IOException) {
e.printStackTrace()
null
}
photoFile?.also {
val photoURI =
FileProvider.getUriForFile(context, "com.your.package.name", it)
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI)
launcher.launch(takePictureIntent)
}
} else {
val timestamp =
SimpleDateFormat("yyyyMMdd_HHmmss", Locale.getDefault()).format(Date())
val path = "${Environment.DIRECTORY_PICTURES}${File.separator}PoCkDetection"
val values = createContentValues(timestamp, path)
val photoURI = context.contentResolver.insert(
MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values
)
targetUri = photoURI
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI)
launcher.launch(takePictureIntent)
}
}
}
}
}
对于 SDK < 29，我遵循 Google Developer
中的代码这是我的清单在遵循代码后的样子：
<application ...>
<provider
android:name="androidx.core.content.FileProvider"
android:authorities="com.your.package.name"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/camera_paths" />
</provider>
</application>
创建名为 xml 的新 res 文件夹，然后创建新的 xml 文件，确保名称与您放置在 <provider> 中的 <meta-data> 和该文件中的名称相同：
<?xml version="1.0" encoding="utf-8"?>
<paths>
<external-files-path
name="camera_take"
path="Pictures" />
</paths>