可一个类扩展两个类？两个
我的类应该扩展两个类在同一时间：
公共类preferences延伸AbstractBillingActivity {
公共类preferences扩展preferenceActivity {
怎么办呢？
UPD 。由于这是不可能的，我应该怎么使用 AbstractBillingActivity 用preferences呢？
UPD2 。如果我去的接口，应创建：
BillingInterface
公共接口BillingInterface扩展preferenceActivity，AbstractBillingActivity {
}
preferenceActivity
公共接口preferenceActivity {
}
AbstractBillingActivity
公共接口AbstractBillingActivity {
无效的onCreate（包savedInstanceState）;
}
然后
公共类preferences实现BillingInterface {
解决方案
Java不支持多重继承。
有几个解决方法我能想到的：
首先是聚集：做一个类，需要这两个活动领域
二是使用接口。
三是要重新考虑你的设计：是否有意义了 preferences 类既是 preferenceActivity 的和的的 AbstractBillingActivity ？
My class should extend two classes at the same time:
public class Preferences extends AbstractBillingActivity {
public class Preferences extends PreferenceActivity {
How to do so?
Upd. Since this is not possible, how should I use that AbstractBillingActivity with Preferences then?
Upd2. If I go with interfaces, should I create:
BillingInterface
public interface BillingInterface extends PreferenceActivity, AbstractBillingActivity {
}
PreferenceActivity
public interface PreferenceActivity {
}
AbstractBillingActivity
public interface AbstractBillingActivity {
void onCreate(Bundle savedInstanceState);
}
and then
public class Preferences implements BillingInterface {
解决方案
Java does not support multiple inheritance.
There are a few workarounds I can think of:
The first is aggregation: make a class that takes those two activities as fields.
The second is to use interfaces.
The third is to rethink your design: does it make sense for a Preferences class to be both a PreferenceActivity and an AbstractBillingActivity?
