保留、重用、释放？

Question

我有一系列按钮，每个按钮都使用不同的图像。我可以重用如下所示的保留变量吗：

// set images
UIImage *image = [[dice1 backgroundImageForState:UIControlStateHighlighted] retain];
[dice1 setBackgroundImage:image forState:(UIControlStateHighlighted|UIControlStateSelected)];
image = [dice2 backgroundImageForState:UIControlStateHighlighted];
[dice2 setBackgroundImage:image forState:(UIControlStateHighlighted|UIControlStateSelected)];
image = [dice3 backgroundImageForState:UIControlStateHighlighted];
[dice3 setBackgroundImage:image forState:(UIControlStateHighlighted|UIControlStateSelected)];
image = [dice4 backgroundImageForState:UIControlStateHighlighted];
[dice4 setBackgroundImage:image forState:(UIControlStateHighlighted|UIControlStateSelected)];
image = [dice5 backgroundImageForState:UIControlStateHighlighted];
[dice5 setBackgroundImage:image forState:(UIControlStateHighlighted|UIControlStateSelected)];
image = [dice6 backgroundImageForState:UIControlStateHighlighted];
[dice6 setBackgroundImage:image forState:(UIControlStateHighlighted|UIControlStateSelected)];
[image release];

还是需要为传递给每个按钮的 setBackgroundImage: 的每个图像创建一个新的 UIImage 并依赖自动释放而不是保留UIImage。上面的方法有效，但我不确定将每个按钮的图像设置为同一图像将如何影响保留计数。

Answer 1

你所拥有的将会泄漏（因为你失去了对第一个图像的引用）并崩溃（因为你释放一个不属于你的对象）。如果删除 -retain 和 -release，您的代码将正常工作。