如何在Android中从内存中选择图像

Question

This is my code:

Intent in = new   Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI); 
               startActivityForResult( in, SELECT_PICTURE);



   public void onActivityResult(int requestCode, int resultCode, Intent data) {
            if (resultCode == RESULT_OK) {

                if (requestCode == SELECT_PICTURE) {

                    //copy selected image to temp directory
                    Uri selectedImageUri = data.getData();

                    File src =  new File(getRealPathFromURI(selectedImageUri));
                    File dst =  new File(pathstring) ;                  

                     try {
                         copy ( src,   dst) ;

                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    } 


            }
....
}

public String getRealPathFromURI(Uri contentUri) {

            // can post image
            String [] proj={MediaStore.Images.Media.DATA};
            Cursor cursor = managedQuery( contentUri,
                            proj, // Which columns to return
                            null,       // WHERE clause; which rows to return (all rows)
                            null,       // WHERE clause selection arguments (none)
                            null); // Order-by clause (ascending by name)
            int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
            cursor.moveToFirst();

            return cursor.getString(column_index);
    }

I get an error on Android 6.0.1 but it works on a device with Android 4.4.2

How can i get an existing image accross all versions?

Answer 1

You are getting an error on Android 6.0.1 because Marshmallow version requires to follow permission model.

You should be checking if the user has granted permission of external storage by using:

if (Build.VERSION.SDK_INT >= 23) {
  if (checkSelfPermission(android.Manifest.permission.WRITE_EXTERNAL_STORAGE)
            == PackageManager.PERMISSION_GRANTED) {
        Log.v(TAG,"Permission is granted");

        //Start doing your stuff to get image from external storage
        Intent in = new   Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI); 
        startActivityForResult( in, SELECT_PICTURE);

  }else{

  //If not, you need to ask the user to grant your app a permission:
   ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUEST_CODE);
  }

}

Make sure that your activity implements OnRequestPermissionResult

So if user will approve the permission,following callback will help you to move forward with your stuffs

 @Override
 public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
     super.onRequestPermissionsResult(requestCode, permissions, grantResults);
     if(grantResults[0]== PackageManager.PERMISSION_GRANTED){
     Log.v(TAG,"Permission: "+permissions[0]+ "was "+grantResults[0]);

      //Start doing your stuff to get image from external storage
        Intent in = new   Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI); 
        startActivityForResult( in, SELECT_PICTURE);
   }
}