I have a small application with some detail controller. Detail controller is a web view put inside scroll view: Here is a code of detail view controller:
- (void)loadScrollViewWithPage:(int)page
{
if (page < 0)
return;
if (page >= detailTotalJobs)
return;
// replace the placeholder if necessary
SearchJobDetailWebViewController *controller = [viewControllers objectAtIndex:page];
if ((NSNull *)controller == [NSNull null])
{
NSLog(@"Vytvaram web controller: %d", page + 1);
if (detailJobIndex == page) {
controller = [[SearchJobDetailWebViewController alloc] initWithNibName:@"SearchJobDetailWebViewController" bundle:nil page:page url:detailExportUrl];
[viewControllers replaceObjectAtIndex:page withObject:controller];
[controller release];
} else if (detailJobIndex + 1 == page) {
controller = [[SearchJobDetailWebViewController alloc] initWithNibName:@"SearchJobDetailWebViewController" bundle:nil page:page url:detailNextExportUrl];
[viewControllers replaceObjectAtIndex:page withObject:controller];
[controller release];
} else {
[self performSelector:@selector(downloadData:) withObject:[NSNumber numberWithInt:page] afterDelay:0.1];
//[self downloadData:[NSNumber numberWithInt:page]];
controller = [[SearchJobDetailWebViewController alloc] initWithNibName:@"SearchJobDetailWebViewController" bundle:nil page:page url:nextArray.exportUrl];
[viewControllers replaceObjectAtIndex:page withObject:controller];
[controller release];
}
}
// add the controller's view to the scroll view
if (controller.view.superview == nil)
{
CGRect frame = scrollView.frame;
frame.origin.x = frame.size.width * page;
frame.origin.y = 0;
controller.view.frame = frame;
[scrollView addSubview:controller.view];
//NSDictionary *numberItem = [self.contentList objectAtIndex:page];
//controller.numberImage.image = [UIImage imageNamed:[numberItem valueForKey:ImageKey]];
//controller.myLabel.text = @"Test";
}
}
- (void)scrollViewDidScroll:(UIScrollView *)sender
{ // We don't want a "feedback loop" between the UIPageControl and the scroll delegate in // which a scroll event generated from the user hitting the page control triggers updates from // the delegate method. We use a boolean to disable the delegate logic when the page control is used. if (pageControlUsed) { // do nothing - the scroll was initiated from the page control, not the user dragging return; }
// Switch the indicator when more than 50% of the previous/next page is visible
CGFloat pageWidth = scrollView.frame.size.width;
int page = floor((scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1;
pageControl.currentPage = page;
NSString *detailTitleText = [NSString stringWithFormat:@"%d / %d", page + 1, detailTotalJobs];
[self setTitle:detailTitleText];
//[detailTitleText release];
// load the visible page and the page on either side of it (to avoid flashes when the user starts scrolling)
[self loadScrollViewWithPage:page - 1];
[self loadScrollViewWithPage:page];
[self loadScrollViewWithPage:page + 1];
// A possible optimization would be to unload the views+controllers which are no longer visible
}
Code inspired by Apple page control.
Problem is here:
if (detailJobIndex == page) {
controller = [[SearchJobDetailWebViewController alloc] initWithNibName:@"SearchJobDetailWebViewController" bundle:nil page:page url:detailExportUrl];
[viewControllers replaceObjectAtIndex:page withObject:controller];
[controller release];
} else if (detailJobIndex + 1 == page) {
controller = [[SearchJobDetailWebViewController alloc] initWithNibName:@"SearchJobDetailWebViewController" bundle:nil page:page url:detailNextExportUrl];
[viewControllers replaceObjectAtIndex:page withObject:controller];
[controller release];
} else {
[self performSelector:@selector(downloadData:) withObject:[NSNumber numberWithInt:page] afterDelay:0.1];
//[self downloadData:[NSNumber numberWithInt:page]];
controller = [[SearchJobDetailWebViewController alloc] initWithNibName:@"SearchJobDetailWebViewController" bundle:nil page:page url:nextArray.exportUrl];
[viewControllers replaceObjectAtIndex:page withObject:controller];
[controller release];
}
First part and second part of if work correctly, because I have data for first web view and for second web view.
But last part of if have a problem. when I scroll from second web view to third web view, scroll view show blank page. Next pages work correctly. Where is problem, please ?
