如何在iOS中設置動畫線程？

我有一個功能drawView這是線程安全的，並繪製短期的遊戲動畫。我有功能startAnimating和stopAnimating。我想要一個後臺線程以正常速率調用drawView，但只能在啓用動畫期間。如何在iOS中設置動畫線程？

在startAnimating我打電話給視圖的performSelectorInBackground:withObject:讓線程運行。

我對如何進行線程通信和初始化繪圖線程有點困惑：特別是，設置runloop來接收顯示鏈接消息，然後在最後通知線程它應該退出並退出運行當從主線程調用stopAnimating時，乾淨地循環。我想確保drawView在stopAnimating之後永遠不會被調用，並且繪圖線程在繪圖操作過程中不會突然取消。在線上我看到了很多非常差的答案。

// object members 
NSThread *m_animationthread; 
BOOL m_animationthreadrunning; 

- (void)startAnimating 
{ 
    //called from UI thread 
    DEBUG_LOG(@"creating animation thread"); 
    m_animationthread = [[NSThread alloc] initWithTarget:self selector:@selector(animationThread:) object:nil]; 
    [m_animationthread start]; 
} 

- (void)stopAnimating 
{ 
    // called from UI thread 
    DEBUG_LOG(@"quitting animationthread"); 
    [self performSelector:@selector(quitAnimationThread) onThread:m_animationthread withObject:nil waitUntilDone:NO]; 

    // wait until thread actually exits 
    while(![m_animationthread isFinished]) 
     [NSThread sleepForTimeInterval:0.01]; 
    DEBUG_LOG(@"thread exited"); 

    [m_animationthread release]; 
    m_animationthread = nil; 
} 

- (void)animationThread:(id)object 
{ 
    @autoreleasepool 
    { 
     DEBUG_LOG(@"animation thread started"); 
     m_animationthreadrunning = YES; 

     NSRunLoop *runLoop = [NSRunLoop currentRunLoop]; 

     CADisplayLink *displaylink = [CADisplayLink displayLinkWithTarget:self selector:@selector(displayLinkAction:)]; 
     [displaylink setFrameInterval:3]; 

     [displaylink addToRunLoop:runLoop forMode:NSDefaultRunLoopMode]; 

     while(m_animationthreadrunning) 
     { 
      [runLoop runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]]; 
      DEBUG_LOG(@"runloop gap"); 
     } 

     [displaylink removeFromRunLoop:runLoop forMode:NSDefaultRunLoopMode]; 

     DEBUG_LOG(@"animation thread quit"); 
    } 
} 

- (void)quitAnimationThread 
{ 
    DEBUG_LOG(@"quitanimationthread called"); 
    m_animationthreadrunning = NO; 
} 

- (void)displayLinkAction:(CADisplayLink *)sender 
{ 
    DEBUG_LOG(@"display link called"); 
    //[self drawView]; 
}

我用線[self performSelector:@selector(quitAnimationThread) onThread:m_animationthread withObject:nil waitUntilDone:NO]，而不是簡單地設置m_animationthreadrunning = NO在stopAnimating是因爲運行的循環可能不會返回的原因：

來源

2013-03-17 Robotbugs

OK閱讀蘋果的網頁一晚上後，我終於與此代碼解決了它以及時的方式，但調用選擇器迫使它返回。

來源

2013-03-17 08:34:10 Robotbugs

如何在iOS中設置動畫線程？

回答

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