在我的情况下，我使用这段代码来避免在锁屏中进行粘贴板检查（事实上，在锁屏中调用applicationDidBecomeActive时，pasteboardChangeCount将为零）

- (void)checkPasteBoard
{
    static NSInteger lastCount = 0;
    NSInteger pasteboardChangeCount = [UIPasteboard generalPasteboard].changeCount;
    if (lastCount != pasteboardChangeCount && pasteboardChangeCount != 0)
    {
        lastCount = pasteboardChangeCount;
    }
    else
    {
        return;
    }