我想要做的是将图像保存到手机内存中,而不是SD卡。
我该怎么做?
我已经成功地从相机直接将图像加载到我的应用程序中的ImageView中了。
现在我想将此图像从ImageView保存到我的Android设备的内部存储器,并在需要时访问它。
有人可以请指导我如何做到这一点吗?
我对Android还有些陌生,因此,请提供详细的步骤,谢谢。
我想要做的是将图像保存到手机内存中,而不是SD卡。
我该怎么做?
我已经成功地从相机直接将图像加载到我的应用程序中的ImageView中了。
现在我想将此图像从ImageView保存到我的Android设备的内部存储器,并在需要时访问它。
有人可以请指导我如何做到这一点吗?
我对Android还有些陌生,因此,请提供详细的步骤,谢谢。
使用下面的代码将图像保存到内部目录。
private String saveToInternalStorage(Bitmap bitmapImage){
ContextWrapper cw = new ContextWrapper(getApplicationContext());
// path to /data/data/yourapp/app_data/imageDir
File directory = cw.getDir("imageDir", Context.MODE_PRIVATE);
// Create imageDir
File mypath=new File(directory,"profile.jpg");
FileOutputStream fos = null;
try {
fos = new FileOutputStream(mypath);
// Use the compress method on the BitMap object to write image to the OutputStream
bitmapImage.compress(Bitmap.CompressFormat.PNG, 100, fos);
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return directory.getAbsolutePath();
}
说明:
1.将以给定的名称创建目录。Javadocs用于指示它将在何处创建目录。
2.您需要提供所需保存的图像名称。
要从内部存储器中读取文件,请使用以下代码。
private void loadImageFromStorage(String path)
{
try {
File f=new File(path, "profile.jpg");
Bitmap b = BitmapFactory.decodeStream(new FileInputStream(f));
ImageView img=(ImageView)findViewById(R.id.imgPicker);
img.setImageBitmap(b);
}
catch (FileNotFoundException e)
{
e.printStackTrace();
}
}
loadImageFromStorage
中传递了哪个路径?如何获取它? - uniruddh/data/data/yourapp/app_data/imageDir
精确地位于哪里?http://stackoverflow.com/questions/40323126/where-do-i-find-the-saved-image-in-android - Khalil Khalaf/**
* Created by Ilya Gazman on 3/6/2016.
*/
public class ImageSaver {
private String directoryName = "images";
private String fileName = "image.png";
private Context context;
private boolean external;
public ImageSaver(Context context) {
this.context = context;
}
public ImageSaver setFileName(String fileName) {
this.fileName = fileName;
return this;
}
public ImageSaver setExternal(boolean external) {
this.external = external;
return this;
}
public ImageSaver setDirectoryName(String directoryName) {
this.directoryName = directoryName;
return this;
}
public void save(Bitmap bitmapImage) {
FileOutputStream fileOutputStream = null;
try {
fileOutputStream = new FileOutputStream(createFile());
bitmapImage.compress(Bitmap.CompressFormat.PNG, 100, fileOutputStream);
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (fileOutputStream != null) {
fileOutputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
@NonNull
private File createFile() {
File directory;
if(external){
directory = getAlbumStorageDir(directoryName);
}
else {
directory = context.getDir(directoryName, Context.MODE_PRIVATE);
}
if(!directory.exists() && !directory.mkdirs()){
Log.e("ImageSaver","Error creating directory " + directory);
}
return new File(directory, fileName);
}
private File getAlbumStorageDir(String albumName) {
return new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES), albumName);
}
public static boolean isExternalStorageWritable() {
String state = Environment.getExternalStorageState();
return Environment.MEDIA_MOUNTED.equals(state);
}
public static boolean isExternalStorageReadable() {
String state = Environment.getExternalStorageState();
return Environment.MEDIA_MOUNTED.equals(state) ||
Environment.MEDIA_MOUNTED_READ_ONLY.equals(state);
}
public Bitmap load() {
FileInputStream inputStream = null;
try {
inputStream = new FileInputStream(createFile());
return BitmapFactory.decodeStream(inputStream);
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (inputStream != null) {
inputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
}
保存:
new ImageSaver(context).
setFileName("myImage.png").
setDirectoryName("images").
save(bitmap);
加载:
Bitmap bitmap = new ImageSaver(context).
setFileName("myImage.png").
setDirectoryName("images").
load();
编辑:
添加了ImageSaver.setExternal(boolean)
以支持根据谷歌的示例保存到外部存储。
public boolean deleteFile(){ File file = createFile(); return file.delete(); }
该方法会创建一个文件并尝试删除它,最后返回删除操作是否成功的布尔值。 - Micropublic void saveImage(Context context, Bitmap bitmap, String name, String extension){
name = name + "." + extension;
FileOutputStream fileOutputStream;
try {
fileOutputStream = context.openFileOutput(name, Context.MODE_PRIVATE);
bitmap.compress(Bitmap.CompressFormat.JPEG, 90, fileOutputStream);
fileOutputStream.close();
} catch (Exception e) {
e.printStackTrace();
}
}
同样,阅读相同内容,请使用此选项
public Bitmap loadImageBitmap(Context context,String name,String extension){
name = name + "." + extension
FileInputStream fileInputStream
Bitmap bitmap = null;
try{
fileInputStream = context.openFileInput(name);
bitmap = BitmapFactory.decodeStream(fileInputStream);
fileInputStream.close();
} catch(Exception e) {
e.printStackTrace();
}
return bitmap;
}
对于 Kotlin 用户,我创建了一个 ImageStorageManager
类,它可以轻松处理图像的保存、获取和删除操作:
class ImageStorageManager {
companion object {
fun saveToInternalStorage(context: Context, bitmapImage: Bitmap, imageFileName: String): String {
context.openFileOutput(imageFileName, Context.MODE_PRIVATE).use { fos ->
bitmapImage.compress(Bitmap.CompressFormat.PNG, 25, fos)
}
return context.filesDir.absolutePath
}
fun getImageFromInternalStorage(context: Context, imageFileName: String): Bitmap? {
val directory = context.filesDir
val file = File(directory, imageFileName)
return BitmapFactory.decodeStream(FileInputStream(file))
}
fun deleteImageFromInternalStorage(context: Context, imageFileName: String): Boolean {
val dir = context.filesDir
val file = File(dir, imageFileName)
return file.delete()
}
}
}
点击这里了解更多信息。
imageFileName
即可检索它。 - Amiraslan这段代码支持Android 11+。
在Fragment / Activity中声明权限结果 我正在使用一个Fragment。
private val askPermissions =
registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) { permissions ->
val isGranted = permissions.entries.all {
it.value == true
}
if (isGranted) {
viewModel.saveImageToGallery(requireContext().contentResolver,
getString(R.string.my_deshi_qr_code),
bitmap)
} else {
askForWritePermission()
}
}
触发事件
bindingView.downloadQrButton.setOnClickListener {
requestPermission()
}
private fun requestPermission() {
val minSDK = Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q
val isWritePermissionGranted = (ContextCompat.checkSelfPermission(requireContext(),
Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) || minSDK
if (!isWritePermissionGranted) {
askForWritePermission()
} else {
viewModel.saveImageToGallery(requireContext().contentResolver,
getString(R.string.my_deshi_qr_code),
bitmap)
}
}
private fun askForWritePermission() {
askPermissions.launch(listOf(Manifest.permission.WRITE_EXTERNAL_STORAGE).toTypedArray())
}
Viewmodel
fun saveImageToGallery(contentResolver: ContentResolver, imageName: String, bitmap: Bitmap?) {
val imageUri: Uri?
val contentValues = ContentValues().apply {
put(MediaStore.MediaColumns.DISPLAY_NAME, "$imageName.jpg")
put(MediaStore.MediaColumns.MIME_TYPE, "image/jpeg")
bitmap?.let {
put(MediaStore.Images.Media.WIDTH, bitmap.width)
put(MediaStore.Images.Media.HEIGHT, bitmap.height)
}
}
imageUri = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
contentValues.put(MediaStore.MediaColumns.RELATIVE_PATH,
Environment.DIRECTORY_PICTURES + File.separator.toString() + "YourFolderName")
MediaStore.Images.Media.getContentUri(MediaStore.VOLUME_EXTERNAL_PRIMARY)
} else {
MediaStore.Images.Media.EXTERNAL_CONTENT_URI
}
try {
val uri = contentResolver.insert(imageUri, contentValues)
val fos = uri?.let { contentResolver.openOutputStream(it) }
bitmap?.compress(Bitmap.CompressFormat.JPEG, 100, fos)
Objects.requireNonNull(fos)
_showMessage.postValue(Event("Image Saved"))
} catch (e: Exception) {
_showMessage.postValue(Event("Image Not Saved \n$e"))
}
}
请确保将WEBP作为您的媒体格式,以在保持相同质量的情况下节省更多空间:
fun saveImage(context: Context, bitmap: Bitmap, name: String): String {
context.openFileOutput(name, Context.MODE_PRIVATE).use { fos ->
bitmap.compress(Bitmap.CompressFormat.WEBP, 25, fos)
}
return context.filesDir.absolutePath
}
// 多图检索
File folPath = new File(getIntent().getStringExtra("folder_path"));
File[] imagep = folPath.listFiles();
for (int i = 0; i < imagep.length ; i++) {
imageModelList.add(new ImageModel(imagep[i].getAbsolutePath(), Uri.parse(imagep[i].getAbsolutePath())));
}
imagesAdapter.notifyDataSetChanged();
如果您想要遵循Android 10的存储编写实践,请查看此处 如果您只想让图像应用程序特定,请查看此处 例如,如果您想要存储一个仅供您的应用程序使用的图像:
viewModelScope.launch(Dispatchers.IO) {
getApplication<Application>().openFileOutput(filename, Context.MODE_PRIVATE).use {
bitmap.compress(Bitmap.CompressFormat.PNG, 50, it)
}
}
getApplication是一种为ViewModel提供上下文的方法,它是AndroidViewModel的一部分。稍后如果您想阅读它:
viewModelScope.launch(Dispatchers.IO) {
val savedBitmap = BitmapFactory.decodeStream(
getApplication<App>().openFileInput(filename).readBytes().inputStream()
)
}
/data/data/yourapp/app_data/imageDir
这个路径具体在哪里?http://stackoverflow.com/questions/40323126/where-do-i-find-the-saved-image-in-android - Khalil Khalaf