全局获取Context

public class MyApplication extends Application {
public static Context context;
@Override
public void onCreate() {
super.onCreate();
context = getApplicationContext();
}

public static Context getContext() {
return context;
}
}

继承Application获得一个应用程序级别的Context,之后在任何的类中需要context调用MyApplication.getContext即可，需要在<application 标签下配置name 告诉程序启动初始化MyApplication