我可以使用以下代码安装存储在SD卡上的apk文件：
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(Uri.fromFile(new File("/mnt/sdcard/downloads/Sample.apk")),"application/vnd.android.package-archive");
startActivity(intent);
解决方法
使用以下代码在sdcard上写入文件：
How to copy files from ‘assets’ folder to sdcard?
从该路径安装如下：
How to copy files from ‘assets’ folder to sdcard?
从该路径安装如下：
Intent intent = new Intent(Intent.ACTION_VIEW); intent.setDataAndType(Uri.fromFile(new File(Environment.getExternalStorageDirectory() + "/download/" + "app.apk")),"application/vnd.android.package-archive"); startActivity(intent);
