The Android package name has been changed, and the previous signature can still be used. What signature is used has nothing to do with the package name. \x0d\ Using the same digital certificate as far as possible for multiple programs of the same developer can bring the following benefits: \x0d\ 1. Conducive to program upgrade. When the digital certificates of the new program and the old program are the same, the Android system will think that the two programs are different versions of the same program. If the digital certificates of the new program and the old program are different, the Android system thinks that they are different programs and conflict, and requires the new program to change the package name; \x0d\2。 This is beneficial to the modular design and development of the program. Android system allows programs with the same digital signature to run in one process, and Android programs will treat them as the same program. Therefore, developers can develop their own programs in a modular way, and users only need to download the corresponding modules when needed; \x0d\3。 You can * * * share data and code among multiple programs through permissions. Android provides a permission granting mechanism based on digital certificates, and applications can share functions or data with other programs to those programs that have the same digital certificates as themselves. If the protection level of the right is signature, the right can only be granted to programs with the same digital certificate as the package in which the right resides.