需求是獲得使用者截圖，或者拍照的主動存圖行為。

但是 android 官方沒有提供回撥廣播之類的實現監聽，所以需要用另一種方式達到需求，這裡實現的就是通過監聽media資料夾實現目的。

所需許可權： 

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

public abstract class ScreenShotContentObserver extends ContentObserver {

    private Context context;
    private boolean isFromEdit = false;
    private String previousPath;

    public ScreenShotContentObserver(Handler handler, Context context) {
        super(handler);
        this.context = context;
    }

    @Override
    public boolean deliverSelfNotifications() {
        return super.deliverSelfNotifications();
    }

    @Override
    public void onChange(boolean selfChange) {
        super.onChange(selfChange);
    }

    @Override
    public void onChange(boolean selfChange, Uri uri) {
        Cursor cursor = null;
        try {
            cursor = context.getContentResolver().query(uri, new String[]{
                    MediaStore.Images.Media.DISPLAY_NAME,
                    MediaStore.Images.Media.DATA
            }, null, null, null);
            if (cursor != null && cursor.moveToLast()) {
                int displayNameColumnIndex = cursor.getColumnIndex(MediaStore.Images.Media.DISPLAY_NAME);
                int dataColumnIndex = cursor.getColumnIndex(MediaStore.Images.Media.DATA);
                String fileName = cursor.getString(displayNameColumnIndex);
                String path = cursor.getString(dataColumnIndex);
//                if (new File(path).lastModified() >= System.currentTimeMillis() - 10000) {
//                    if (isScreenshot(path) && !isFromEdit && !(previousPath != null && previousPath.equals(path))) {
//                        onScreenShot(path, fileName);
//                    }
//                    previousPath = path;
//                    isFromEdit = false;
//                } else {
//                    cursor.close();
//                    return;
//                }
                Log.e("take pic", fileName + "----" + path);
            }
        } catch (Exception e) {
            e.printStackTrace();
            isFromEdit = true;
        } finally {
            if (cursor != null) {
                cursor.close();
            }
        }
        super.onChange(selfChange, uri);
    }

    private boolean isScreenshot(String path) {
        return path != null && path.toLowerCase().contains("screenshot");
    }

    protected abstract void onScreenShot(String path, String fileName);

}
 

public class MainActivity extends AppCompatActivity {

    private ScreenShotContentObserver screenShotContentObserver;
    private Handler handler = new Handler();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        screenShotContentObserver = new ScreenShotContentObserver(handler, this) {
            @Override
            protected void onScreenShot(String path, String fileName) {
            }
        };

    }

    @Override
    public void onResume() {
        super.onResume();

        getContentResolver().registerContentObserver(
                MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                true,
                screenShotContentObserver
        );
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        try {
            getContentResolver().unregisterContentObserver(screenShotContentObserver);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}
 

Screenshot_2018-02-19-07-09-48.jpeg----/storage/emulated/0/Pictures/Screenshots/Screenshot_2018-02-19-07-09-48.jpeg

IMG_20180219_071018.jpg----/storage/emulated/0/DCIM/Camera/IMG_20180219_071018.jpg

原始碼下載: