我被这个问题困住了我有一系列的CharacterView类直接进入UIScrollView。
加载部分是非常性能密集的,因为这个原因,我试图通过线程场景的帮助来管理它。
我的意图是加载所请求的页面(例如第10页中的第5页)并开始加载此UIScrollView的所有页面并立即在屏幕上显示,然后以某种方式重复并加载+1/-1 (分别为6和4)和屏幕上的显示,然后在第二次递归中加载+2/-2(第7和第3)和show'em屏幕上等。强制UIScrollView更新
这是代码:
-(void)loadPagesDrillingFromPage:(NSInteger) page {
self.viewControllers = [[[NSMutableArray alloc] init] autorelease];
for (unsigned i = 0; i < [pageIds count]; i++) {
[self.viewControllers addObject:[NSNull null]];
}
pageControl.numberOfPages = [pageIds count];
didPreparePagesContainer = YES;
if (kPRELOADALLPAGES && !threadIsLoadingPages) {
threadIsLoadingPages = YES;
NSNumber *startingPage = [NSNumber numberWithInt:page];
NSMutableArray *preloadedPages = [[[NSMutableArray alloc] init] autorelease];
[NSThread detachNewThreadSelector:@selector(drillPagesFrom:) toTarget:self withObject:startingPage];
}
}
,你可以在此功能中看到我们从开始调用与选择drillPagesFrom线程声明:(NSNumber的*)页,其定义广告如下:
-(void)drillPagesFrom:(NSNumber *) page {
NSInteger pg = [page intValue];
CharacterView *controller = [self.viewControllers objectAtIndex:pg];
if((NSNull *)controller != [NSNull null])
return;
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
NSLog(@"DRILLING page %i", pg);
controller = [[CharacterView alloc]
initWithNibName:@"CharacterView"
bundle:[NSBundle mainBundle]];
controller.didLoad = NO;
controller.position = pg;
controller.containerItemsCount = [self.pageIds count];
controller.delegate = self;
CGRect frame = self.scrollView.frame;
frame.origin.x = frame.size.width * pg;
frame.origin.y = 0;
controller.view.frame = frame;
[controller setCat_name:self.cat_name];
[controller fetchCharacter:[self.pageIds objectAtIndex:pg] WithMOC:self._context];
[self.viewControllers replaceObjectAtIndex:pg withObject:controller];
[self performSelectorOnMainThread:@selector(updateScrollView:) withObject:controller waitUntilDone:NO];
[controller release];
if(pg > 1)// && !threadReachedFirstPage)
{
NSNumber *prevPg = [NSNumber numberWithInt:pg-1];
[self drillPagesFrom:prevPg];
}
if(pg < [self.pageIds count]-1)// && !threadReachedLastPage)
{
NSNumber *nextPg = [NSNumber numberWithInt:pg+1];
[self drillPagesFrom:nextPg];
}
[pool release];
}
各种测试后,我已经尝试通过调用主线程,强制的UIScrollView的重绘,你可以在上面的代码中
[self performSelectorOnMainThread:@selector(updateScrollView:) withObject:controller waitUntilDone:NO];
注意函数updateScrollView是
- (void) updateScrollView:(CharacterView *)controller {
[self.scrollView addSubview:[controller view]];
[self.scrollView setNeedsDisplay];
}
尽管所有这些代码仍然等待显示任何n屏幕之前加载所有页面,这是非常非常烦人的,因为你看到约2秒的空白空间。
希望能够以一种明确的方式解释问题,
我在此先感谢您。
欢呼
ķ
那么,这是什么问题? – Altealice 2011-02-17 17:28:34