安装app

res/xml/filepaths.xml

Intent intent = new Intent(Intent.ACTION_VIEW);
File apkFile = new File(apkPath);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
    intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
    Uri uri = FileProvider.getUriForFile( MainActivity.this,getPackageName() + ".fileprovider", apkFile);
    intent.setDataAndType(uri, "application/vnd.android.package-archive");
} else {
    intent.setDataAndType(Uri.fromFile(apkFile), "application/vnd.android.package-archive");
}
startActivity(intent);