小编Rya*_*ley的帖子

class foo{
    ....
}

假设我的代码中存在该类,那么稍后我不再需要这个类并希望将其删除(所以我可以稍后用新类替换它)

是否可以从运行时删除整个类？

我在谈论这个:http: //reviews.cnet.com/8301-19512_7-20120625-233/ios-5-notifications-a-deeper-look/

iOS上的那些下拉菜单,我对生活的热爱找不到任何关于如何发出通知的文档,以便在另一个应用程序中显示更新.我不知道我是在使用错误的术语还是什么,但是它是"NSNotificationCenter",它的文档在哪里？

谢谢 :)

typedef enum {
    artists = 0,
    artists_songs = 1,
    artist_albums = 2,
    albums = 3,
    album_songs = 4,
    tags = 5,
    tag = 6,
    tag_artists = 7,
    tag_albums = 8,
    tag_songs = 9,
    songs = 10,
    song = 11,
    playlists = 12,
    playlist = 13,
    playlist_songs = 14,
    search_songs = 15
} Methods;

typedef enum {
    artists = 0,
    albums = 1,
    songs = 2,
    tags = 3,
    playlists = 4    
} ReturnTypes;

我一直在关于ReturnTypes的artists = 0行收到错误,说艺术家已被重新声明.我不确定这是什么语法错误.有任何想法吗？

   SELECT Output.name, Output.avgSalary 
   FROM (SELECT Airplane.aid, Airplane.aname AS name, 
                AVG (worker.salary) AS avgSalary 
         FROM Aircraft Airplane , Certified IsCertified, Employees worker 
         WHERE Airplane.aid = IsCertified.aid AND 
               IsCertified.eid = worker.eid AND 
               Airplane.crusingrange >  1000 
          GROUP BY Airplane.aid, Airplane.aname) AS Output

Oracle SQL在"AS输出"附近说错误,但我无法弄清楚它有什么问题.:S

ERROR at line 1:
ORA-00933: SQL command not properly ended

我有一个黑色轮廓的圆圈和一个白色填充,我需要以编程方式将白色变成另一种颜色(通过UIColor).我尝试了一些其他的stackoverflow解决方案,但它们似乎都没有正常工作,只是填充外部或大纲.

我有两种方法可以做到这一点,但我不确定如何得到正确的结果:

只是白色,无论UIColor应该是什么,

要么,

从两个圆圈中创建一个UIImage,一个被填充,一个与黑色重叠.