2
我正在使用iCarousel滾動標籤。一切工作正常在模擬器上，但在iPad/iPhone上滾動不平穩和快速iCarousel不能平滑滾動
這裏是代碼。
CitiesListView.h
#import <UIKit/UIKit.h>
#import "iCarousel.h"
@interface CitiesListView : UIView <iCarouselDataSource, iCarouselDelegate>
@property (nonatomic, retain) iCarousel *carousel;
@end
CitiesListView.m
#import "CitiesListView.h"
@interface CitiesListView()
@property (nonatomic, retain) NSMutableArray *items;
@end
@implementation CitiesListView
@synthesize carousel;
@synthesize items;
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
[self setUp];
}
return self;
}
- (void)setUp
{
carousel = [[iCarousel alloc]initWithFrame:CGRectMake(0, 0, 300, 200)];
items = [NSMutableArray arrayWithObjects:@"city1", @"city2", @"city3", @"city4", @"city5", @"city6", nil];
[self addSubview:carousel];
carousel.delegate = self;
carousel.dataSource = self;
carousel.type = iCarouselTypeRotary;
}
- (id)initWithCoder:(NSCoder *)aDecoder
{
if ((self = [super initWithCoder:aDecoder]))
{
[self setUp];
}
return self;
}
#pragma mark iCarousel methods
- (NSUInteger)numberOfItemsInCarousel:(iCarousel *)carousel
{
return [items count];
}
- (UIView *)carousel:(iCarousel *)carousel viewForItemAtIndex:(NSUInteger)index reusingView:(UIView *)view
{
UILabel *label = nil;
//create new view if no view is available for recycling
if (view == nil)
{
view = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 200.0f, 200.0f)];
((UIImageView *)view).image = [UIImage imageNamed:@"labelBackground.png"];
view.contentMode = UIViewContentModeCenter;
label = [[UILabel alloc] initWithFrame:view.bounds];
label.backgroundColor = [UIColor clearColor];
label.textAlignment = UITextAlignmentCenter;
label.font = [label.font fontWithSize:26];
label.tag = 1;
[view addSubview:label];
} else {
//get a reference to the label in the recycled view
label = (UILabel *)[view viewWithTag:1];
}
//set item label
//remember to always set any properties of your carousel item
//views outside of the `if (view == nil) {...}` check otherwise
//you'll get weird issues with carousel item content appearing
//in the wrong place in the carousel
label.text = [items objectAtIndex:index];
return view;
}
- (NSUInteger)numberOfPlaceholdersInCarousel:(iCarousel *)carousel
{
//note: placeholder views are only displayed on some carousels if wrapping is disabled
return 2;
}
- (UIView *)carousel:(iCarousel *)carousel placeholderViewAtIndex:(NSUInteger)index reusingView:(UIView *)view
{
UILabel *label = nil;
//create new view if no view is available for recycling
if (view == nil)
{
//don't do anything specific to the index within
//this `if (view == nil) {...}` statement because the view will be
//recycled and used with other index values later
view = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 200.0f, 200.0f)];
((UIImageView *)view).image = [UIImage imageNamed:@"labelBackground.png"];
view.contentMode = UIViewContentModeCenter;
label = [[UILabel alloc] initWithFrame:view.bounds];
label.backgroundColor = [UIColor clearColor];
label.textAlignment = UITextAlignmentCenter;
label.font = [label.font fontWithSize:50.0f];
label.tag = 1;
[view addSubview:label];
} else {
//get a reference to the label in the recycled view
label = (UILabel *)[view viewWithTag:1];
}
//set item label
//remember to always set any properties of your carousel item
//views outside of the `if (view == nil) {...}` check otherwise
//you'll get weird issues with carousel item content appearing
//in the wrong place in the carousel
label.text = (index == 0)? @"[": @"]";
return view;
}
- (CATransform3D)carousel:(iCarousel *)_carousel itemTransformForOffset:(CGFloat)offset baseTransform:(CATransform3D)transform
{
//implement 'flip3D' style carousel
transform = CATransform3DRotate(transform, M_PI/8.0f, 0.0f, 1.0f, 0.0f);
return CATransform3DTranslate(transform, 0.0f, 0.0f, offset * carousel.itemWidth);
}
- (CGFloat)carousel:(iCarousel *)_carousel valueForOption:(iCarouselOption)option withDefault:(CGFloat)value
{
//customize carousel display
switch (option)
{
case iCarouselOptionSpacing:
{
//add a bit of spacing between the item views
return value * 1.05f;
}
case iCarouselOptionFadeMax:
{
if (carousel.type == iCarouselTypeCustom)
{
//set opacity based on distance from camera
return 0.0f;
}
return value;
}
default:
{
return value;
}
}
}
#pragma mark iCarousel taps
- (void)carousel:(iCarousel *)carousel didSelectItemAtIndex:(NSInteger)index
{
NSNumber *item = [self.items objectAtIndex:index];
NSLog(@"Tapped view number: %@", item);
}
@end
而在我的視圖控制器分配/ initWithFrame CitiesListView並加入到self.view。
我做錯了什麼。我需要標籤像例子一樣平滑滾動。
謝謝。
您可能想要在樂器中剖析您的代碼，以查看是否存在影響應用性能的特定區域。使用Time Profiler工具。有關如何使用樂器的詳細信息，請參閱Apple的文檔：http://developer.apple.com/library/ios/#documentation/DeveloperTools/Conceptual/InstrumentsUserGuide/Introduction/Introduction.html – stevekohls
當我剖析並使用分配樂器旋轉木馬卷軸光滑。無法找到問題並修復 – Mariam
Allocations會告訴您關於您的內存使用情況，但Time Profiler會讓您知道每種方法執行的時間。這可能有助於找出什麼在減慢你的繪圖。確保你也在設備上進行分析。 – stevekohls