When the code is installed apk, install apk assets directly under Why wrong?

            
apk in assets, called abc.apk
Code

 Intent i = new Intent (Intent.ACTION_VIEW); 
i.setDataAndType (Uri.parse ("file :/ / / android_asset / abc.apk"), "application / vnd.android.package-archive"); 
i.addFlags (Intent.FLAG_ACTIVITY_NEW_TASK); 
startActivity (i); 

Why datagram packet parsing error?
Reply:
"Install Applications" This is an application
He did not permission to read the directory of your application asset