有没有保证的解决这个问题的原因是电话号码没有被物理地存储在所有的SIM卡，或者从网络到电话广播。这是特别真实的，需要的物理地址验证，以编号分配仅发生事后一些国家。电话号码分配发生在网络上 - 并能够在不改变SIM卡或装置（例如，这是移植是如何支持）

There is no guaranteed solution to this problem because the phone number is not physically stored on all SIM-cards, or broadcasted from the network to the phone. This is especially true in some countries which requires physical address verification, with number assignment only happening afterwards. Phone number assignment happens on the network - and can be changed without changing the SIM card or device (e.g. this is how porting is supported).

参考：How我可以以编程的API获取Android手机的数量？