NSMutableArray insertObject:atIndex导致崩溃
问题描述:
我正在为iPad创建幻灯片应用程序,当我让用户重新排列幻灯片时遇到了一些麻烦。当调用slideDropped方法时,如果我只是删除幻灯片,然后将其添加到幻灯片的结尾,然后一切工作正常。如果我将5张幻灯片幻灯片放入幻灯片2并将其移至幻灯片3,则当我尝试循环浏览slideshow.slides
(这仅是NSMutableArray
)时,它会在新幻灯片上出现访问错误而崩溃。NSMutableArray insertObject:atIndex导致崩溃
-(void)slideDropped:(Slide *)slide
{
int destIndex = (int)(slide.frame.origin.x)/152;
destIndex = MIN(destIndex, slideshow.slides.count - 1);
destIndex = MAX(0, destIndex);
int sourceIndex = [slideshow.slides indexOfObject:slide];
[slideshow removeSlideAtIndex:sourceIndex];
if(destIndex >= slideshow.slides.count)
[slideshow addSlide:slide];
else
[slideshow insertSlide:slide atIndex:destIndex];
[self arrangeSlides];
}
-(void)arrangeSlides
{
[scrSlideshow.subviews makeObjectsPerformSelector:@selector(removeFromSuperview)];
int x = 0;
NSLog(@"There are %i slides",slideshow.slides.count);
for(Slide* slide in slideshow.slides)
{
NSLog(@"%@",slide);//crashes here on the new slide if I insert at a specific index rather than appending the slide to the end
CGRect frame = CGRectMake(x++ * 152, 21, 150, 150);
slide.frame = frame;
[scrSlideshow addSubview:slide];
}
[scrSlideshow setContentSize:CGSizeMake(slideshow.slides.count * 152, 150)];
}
//in the Slideshow class
-(void)addSlide:(Slide *)slide
{
[slides addObject:slide];
}
-(void)removeSlideAtIndex:(int)index
{
[slides removeObjectAtIndex:index];
}
-(void)insertSlide:(Slide *)slide atIndex:(int)index
{
[slides insertObject:slides atIndex:index];
}
任何想法,我可能做错了什么?我怀疑我没有正确管理幻灯片,但我不知道该怎么做。
答
查看该代码的底部。你有insertObject:slides
。如果这只是“幻灯片”,或者你打算它是复数?这可能是你的问题
谢谢!我一直盯着slideDropped和arrangeSlides方法这么久,我甚至都没想过去检查insertSlide:atIndex:方法。 – nick 2012-07-23 22:50:18