在片段中使用 MediaScannerConnection.scanFile()？

Question

I am downloading a file from within a Fragment asynchronously and would like to call MediaScannerConnection.scanFile() when the download completes. I am able to get desired results if I sit and wait for the download to finish without navigating away from my Fragment (or its hosting activity). The problem I am facing is that MediaScannerConnection.scanFile() requires a context and I don't want to limit the user to staying within a Fragment / Activity just so that context is not null.

How do I make use of MediaScannerConnection.scanFile() in the background so that I can scan the files and display a Toast when the scanning is complete while still navigating in other parts of my app (or even tabbing out of my app)?

This is how I am currently scanning (with a context):

public static void mediaScanFile(Context context, String path) {
    MediaScannerConnection.scanFile(context,
            new String[]{path}, null,
            new MediaScannerConnection.OnScanCompletedListener() {
                public void onScanCompleted(String path, Uri uri) {
                    Log.d("Tag", "Scan finished. You can view the image in the gallery now.");
                }
            });
}

Answer 1

First of all, downloading a file from a Fragment which may be destroyed soon is not a good idea. You should use foreground service instead.

---

If you still want to stick with fragments, in your case, you can make use of the application context.

Before starting the download, store a reference of the application context as a field in your fragment.

Context appContext;

// Inside onCreateView
appContext = getContext().getApplicationContext();

Then you can use the application context for scanning media.

This won't cause memory leak because the application context is a single shared instance and won't be destroyed until the app is killed.