在AndroidManifest.xml文件中添加必要的权限声明以允许使用FilePicker功能。示例如下：

同时，在应用中动态申请权限，示例如下：

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && ActivityCompat.checkSelfPermission(context, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
    requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, PERMISSION_REQUEST_CODE);
    return;
}

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && ActivityCompat.checkSelfPermission(context, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
    requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, PERMISSION_REQUEST_CODE);
    return;
}