在 android 中使用相机拍照后如何永久保存图像？

Question

I know this has been posted here multiple times but none of the solutions is clear enough on what needs to be done. I guess it would help to know that I'm new to android programming.

This is where I create the intent to use camera in the app.

public void captureImage(View view)
    {
        Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

        if(cameraIntent.resolveActivity(getPackageManager())!=null)
        {
            File imageFile = null;
            try {
                imageFile = getImageFile();
            } catch (IOException e) {
                e.printStackTrace();
            }
            if(imageFile!=null)
            {
                Uri imageUri = FileProvider.getUriForFile(this, "com.example.android.fileprovider", imageFile);
                cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
                startActivityForResult(cameraIntent, IMAGE_REQUEST);
            }

        }

    }

Below is the method where I create the image file, where the camera image will be saved TEMPORARILY as I understand.

    public File getImageFile() throws IOException {
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmsss").format(new Date());
        String imageName = "jpg_"+timeStamp+"_";
        File storageDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
        //storageDir.mkdirs();
        perStorageDir=storageDir;
        File imageFile = File.createTempFile(imageName,".jpg", storageDir);
        currentImagePath = imageFile.getAbsolutePath();
        return imageFile;
    }

(Using the currentImagePath I can access the photo only while the app is still running)

1. getExternalFilesDir(Environment.DIRECTORY_PICTURES); crashes my app if I try to call it anywhere outside the function, I have no idea why.

2. File.createTempFile(...) creates only a temporary file. How can I make that a permanent addition?

3. All other relevant files in the project have been modified accordingly to set permissions and features.

All I want to do is to create a directory and store pictures in that every time a photo is taken. Even if I close and reopen the app or not take camera pictures, I'd like to access the folder for older images and such.

Any help would be greatly appreciated!

Answer 1

If you would like to save it permanently, you can save it App-Specific Storage . this is a type of storage assigned to your application package name.

You can find it in path data/data/ your-package-name , check the official documentation to know more about this type of storage.

We should save these images in external storage as well.

Step 1:

Grant external storage permission, as you will access this storage by saving images in it.

Step 2:

Open your camera with Intent and create a file for the taken image.

    private void openCamera() {
    Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
        photoFile = null;
        try {
            photoFile = FileHelper.createImageFile(this);

        } catch (IOException ex) {
        }

        if (photoFile != null) {
            photoURI = FileProvider.getUriForFile(this,
                    "your path",
                    photoFile);
            deleteFile(photoFile.getName());
            takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
            startActivityForResult(takePictureIntent, CAMERA_RESULT);
            photoFile.deleteOnExit();
        }
    }
}

createImageFile() is a method to create a temp file

   public static File createImageFile(Context context) throws IOException {
    // Create an image file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    String imageFileName = timeStamp;
    File storageDir = context.getExternalFilesDir(Environment.DIRECTORY_PICTURES)
    ;
    File image = File.createTempFile(
            imageFileName,  /* prefix */
            ".jpg",         /* suffix */
            storageDir     /* directory */
    );
    return image;
}

Step 3:

Add the path of your file provider

<?xml version="1.0" encoding="utf-8"?>
<paths>
    <external-path
    name="external"
    path="." />
</paths>

In your manifest, declare this file provider path as follows:

<provider
        android:name="androidx.core.content.FileProvider"
        android:authorities="cyour authority"
        android:exported="false"
        android:grantUriPermissions="true">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/file_paths" />
    </provider>

Finally, I have a full repository on GitHub you can explore it, I think it could help you.

Happy Coding