ARC存儲器泄漏

Question

+(void)setup {
    UIImage* spriteSheet = [UIImage imageNamed:@"mySpriteSheet.png"];
    CGRect rect;
    animation = [NSMutableArray arrayWithCapacity:numberOfFramesInSpriteSheet];
    int frameCount = 0;

    for (int row = 0; row < numberFrameRowsInSpriteSheet; row++) {
        for (int col = 0; col < numberFrameColsInSpriteSheet; col++) {
            frameCount++;
            if (frameCount <= numberOfFramesInSpriteSheet) {
                rect = CGRectMake(col*frameHeight, row*frameWidth, frameHeight, frameWidth);
                [animation addObject:[UIImage imageWithCGImage:CGImageCreateWithImageInRect(spriteSheet.CGImage, rect)] ];
            }
         }
    }
}

在啟用ARC的情況下編譯上面的代碼。 Analyze工具報告可能的內存泄漏，因為imageWithCGImage ::返回帶有count +1的UIImage，然后引用丟失。 泄漏儀器報告根本沒有內存泄漏。 這里發生了什么？

此外，由於ARC禁止使用手動release ，如何修復泄漏？

感謝任何能提供任何建議的人。

Answer 1

ARC不管理C類型，可以考慮CGImage。 完成CGImageRelease(image);后，必須手動釋放引用CGImageRelease(image);

+(void)setup {
    UIImage* spriteSheet = [UIImage imageNamed:@"mySpriteSheet.png"];
    CGRect rect;
    animation = [NSMutableArray arrayWithCapacity:numberOfFramesInSpriteSheet];
    int frameCount = 0;

    for (int row = 0; row < numberFrameRowsInSpriteSheet; row++) {
        for (int col = 0; col < numberFrameColsInSpriteSheet; col++) {
            frameCount++;
            if (frameCount <= numberOfFramesInSpriteSheet) {
                rect = CGRectMake(col*frameHeight, row*frameWidth, frameHeight, frameWidth);
                //store our image ref so we can release it later
                //The create rule says that any C-interface method with "create" in it's name 
                //returns a +1 foundation object, which we must release manually.
                CGImageRef image = CGImageCreateWithImageInRect(spriteSheet.CGImage, rect)
                //Create a UIImage from our ref.  It is now owned by UIImage, so we may discard it.
                [animation addObject:[UIImage imageWithCGImage:image]];
                //Discard the ref.  
                CGImageRelease(image);
            }
         }
    }
}

Answer 2

ARC沒有處理任何核心基礎數據結構。 很多時候這會產生問題。 在這些情況下，我們必須手動釋放內存。