ios - Xcode 6.0.1 新警告

Question

在更新到最新版本的 Xcode 之前，我没有收到此错误警告？

Incompatible pointer types initializing 'MPNowPlayingInfoCenter' with an expression of type 'NSNotificationCenter’

代码:

- (void)doUpdateNowPlayingCenter 
{
    if (!self.updateNowPlayingCenter || !self.nowPlayingItem)
    {
        return;
    }

    Class playingInfoCenter = NSClassFromString(@"MPNowPlayingInfoCenter");

    if (!playingInfoCenter)
    {
        return;
    }

    MPNowPlayingInfoCenter *center = [playingInfoCenter defaultCenter];
    NSDictionary *songInfo = @
    {
         MPMediaItemPropertyTitle: [self.nowPlayingItem valueForProperty:MPMediaItemPropertyTitle],
         MPMediaItemPropertyPlaybackDuration: [self.nowPlayingItem valueForProperty:MPMediaItemPropertyPlaybackDuration]
    };

    center.nowPlayingInfo = songInfo;
}

Answer 1

您可以通过以这种方式转换默认中心来消除警告:

MPNowPlayingInfoCenter *center = (MPNowPlayingInfoCenter*)[playingInfoCenter defaultCenter];