android扫描感知相册目录里的新图片

ArrayList toBeScanned = new ArrayList();
File folder_file = new File("sdcard/DCIM/Camera");
File[] files = folder_file.listFiles();
if (files != null) {
    for (File file : files) {
        // checking the File is file or directory
        if (file.isFile()) {
            String path = file.getAbsolutePath();
            toBeScanned.add(path);
        }
    }
}

String[] toBeScannedStr = new String[toBeScanned.size()];
toBeScannedStr = toBeScanned.toArray(toBeScannedStr);

MediaScannerConnection.scanFile(MainActivity.this, toBeScannedStr, null, new MediaScannerConnection.onScanCompletedListener()
{

    @Override
    public void onScanCompleted(String path, Uri uri) {
        System.out.println("SCAN COMPLETED: " + path);

    }
});

其中API的解释： 

 里面的关键类MediaScannerConnection 解释：