我正在使用UICollectionView来呈现一些图像。按下图像时，我希望它突出显示图像。我创建了一个自定义类ImageSelectionViewController，给定一个图像数组创建一个uicollectionview并响应UICollectionViews委托。
单元格的大小取决于提供的图像是纵向还是横向。
我有一个名为 _arrayOfBools 的NSNumbers数组，它存储布尔值，（One）在ImageSelectionViewController内部突出显示，0（未突出显示），用于存储需要突出显示的图像。按下图像时，它会更新arrayOfBools然后重新加载我的UICollectionView以更新所有单元格。
该应用加载得很好，但只要我点击图像两次，就会出现奇怪的格式问题，而图像尺寸不正确。我的项目在XcodeProject。这几乎就像当我为UICollectionView重新加载数据时，单元格的大小正在发生变化。
这是我的ImageViewController.h
//
// ImageSelectionViewController.h
// QUESTIONS
//
// Created by Kingsnorth, Alec (Student) on 15/01/2015.
// Copyright (c) 2015 Kingsnorth, Alec (Student). All rights reserved.
//
#import <UIKit/UIKit.h>
#import "CustomCollectionViewCell.h"
typedef enum imageSelectMode{ICMOne, ICMMulti, ICMZeroOrOne, ICMZeroOrMulti}imageSelectMode;
@interface ImageSelectionViewController : UIViewController <UICollectionViewDataSource,UICollectionViewDelegate,UICollectionViewDelegateFlowLayout>
{
NSMutableArray* arrayImages;
NSMutableArray* imageSizes;
// dimensions and spacings
float collectionViewWidth;
float collectionViewHeight;
float screenWidth;
float screenHeight;
float landscapeHeight;
float portraitHeight;
imageSelectMode imSelectMode;
NSString* test;
//BOOL shouldHighlight;
}
//where the data is kept
@property(nonatomic,retain) NSMutableArray* arrayOfBools;
@property(nonatomic,retain) UICollectionView* collectionView;
-(UIView*)setupWithImages:(NSMutableArray*)imageArray imageSelectMode:(imageSelectMode)mode;
@end
这是我的ImageViewController.m
//
// ImageSelectionViewController.m
// QUESTIONS
//
// Created by Kingsnorth, Alec (Student) on 15/01/2015.
// Copyright (c) 2015 Kingsnorth, Alec (Student). All rights reserved.
//
#import "ImageSelectionViewController.h"
@interface ImageSelectionViewController ()
@end
@implementation ImageSelectionViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(UIView*)setupWithImages:(NSMutableArray*)imageArray imageSelectMode:(imageSelectMode)mode;
{
//House keeping
[self setupDimensions];
_arrayOfBools=[[NSMutableArray alloc] init];
imSelectMode=mode;
for (int i=0; i<[imageArray count]; i++)
{
[_arrayOfBools addObject:[NSNumber numberWithBool:NO]];
}
arrayImages=imageArray;
//setupCollectionView
UICollectionViewFlowLayout *layout=[[UICollectionViewFlowLayout alloc] init];
_collectionView=[[UICollectionView alloc] initWithFrame:CGRectMake(0, 0, collectionViewWidth, collectionViewHeight)collectionViewLayout:layout];
[_collectionView setDataSource:self];
[_collectionView setDelegate:self];
[_collectionView registerClass:[CustomCollectionViewCell class] forCellWithReuseIdentifier:@"CUSTOM"];
[_collectionView setBackgroundColor:[UIColor whiteColor]];
return _collectionView;
}
-(void)setupDimensions
{
screenWidth=768;
screenHeight=1026;
collectionViewWidth=screenWidth-20;
collectionViewHeight=900;
landscapeHeight=240;
portraitHeight=290;
test=[[NSString alloc] init];
}
//Delegate methods----------------------------------//
//----------------------------------------//
//---------------------//
//----//
- (NSInteger)collectionView:(UICollectionView *)collectionView
numberOfItemsInSection:(NSInteger)section
{
return [arrayImages count];
}
- (NSInteger)numberOfSectionsInCollectionView: (UICollectionView *)collectionView {
return 1;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView
cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
CustomCollectionViewCell *cell=[collectionView dequeueReusableCellWithReuseIdentifier:@"CUSTOM" forIndexPath:indexPath];
//NSLog(@"\n arrayOfBools: \n %@",self.arrayOfBools);
[cell updateImage:[arrayImages objectAtIndex:indexPath.item] withHighlight:[[_arrayOfBools objectAtIndex:indexPath.item] boolValue]andItemNo:indexPath.item];
//NSLog(@"\nrowNo:%ld",(long)indexPath.item);
return cell;
}
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
// Choose which mode will affect the highlight properties
if (imSelectMode==ICMOne)
{
for (int i=0; i<[self.arrayOfBools count]; i++)
{
[self.arrayOfBools replaceObjectAtIndex:i withObject:[NSNumber numberWithBool:FALSE]];
}
[self.arrayOfBools replaceObjectAtIndex:indexPath.item withObject:[NSNumber numberWithBool:YES]];
}
else if (imSelectMode==ICMMulti)
{
NSNumber* num=[self.arrayOfBools objectAtIndex:indexPath.item];
NSNumber* replace;
if (num.boolValue==YES)
{
replace=[NSNumber numberWithBool:FALSE];
}
else
{
replace=[NSNumber numberWithBool:TRUE];
}
[self.arrayOfBools replaceObjectAtIndex:indexPath.item withObject:replace];
}
else if (imSelectMode==ICMZeroOrOne)
{
for (int i=0; i<[self.arrayOfBools count]; i++)
{
if (i==indexPath.item)
{
//Do nothing
}
else
{
[self.arrayOfBools replaceObjectAtIndex:i withObject:[NSNumber numberWithBool:FALSE]];
}
}
NSNumber* num=[self.arrayOfBools objectAtIndex:indexPath.item];
NSNumber* replace;
if (num.boolValue==YES)
{
replace=[NSNumber numberWithBool:FALSE];
}
else
{
replace=[NSNumber numberWithBool:TRUE];
}
[self.arrayOfBools replaceObjectAtIndex:indexPath.item withObject:replace];
}
[self updateCollectionView:collectionView];
}
-(void)updateCollectionView:(UICollectionView*)collectionView
{
NSLog(test);
[collectionView reloadItemsAtIndexPaths:[collectionView indexPathsForVisibleItems]];
}
- (CGSize)collectionView:(UICollectionView *)collectionView
layout:(UICollectionViewLayout *)collectionViewLayout
sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
UIImage* currImage=[arrayImages objectAtIndex:indexPath.item];
//find the aspect ratio of the image w1/h1 = w2/h2
float w1=currImage.size.width;
float h1=currImage.size.height;
float ratio=w1/h1;
float h2=0;
float w2=0;
//Resize image to standard sizes
// resize image locking aspect
if (currImage.size.width>currImage.size.height)
{ // image is landscape
h2=landscapeHeight;
}
else
{
//Image is portrait
h2=portraitHeight;
}
w2=ratio*h2;
CGSize toSend;
toSend=CGSizeMake(w2,h2);
//NSString* log=[NSString stringWithFormat:@"\n Index:%ld width:%f height:%f ",(long)indexPath.item,w2,h2];
//test=[test stringByAppendingString:log];
printf([NSString stringWithFormat:@"\n indexPath.item %lu",indexPath.item].UTF8String);
return toSend;
}
- (UIEdgeInsets)collectionView:
(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section
{
return UIEdgeInsetsMake(10, 10, 10, 10);
}
@end
我的CustomCollectionViewCell.h
//
// CustomCollectionViewCell.h
// QUESTIONS
//
// Created by Kingsnorth, Alec (Student) on 15/01/2015.
// Copyright (c) 2015 Kingsnorth, Alec (Student). All rights reserved.
//
#import <UIKit/UIKit.h>
@interface CustomCollectionViewCell : UICollectionViewCell
@property (nonatomic, strong) UIImageView *imageView;
@property (nonatomic, strong) UIImage *image;
-(void)updateImage:(UIImage*)image withHighlight:(BOOL)isHighlighted andItemNo:(NSInteger)item;
@end
我的CustomCollectionViewCell.m
//
// CustomCollectionViewCell.m
// QUESTIONS
//
// Created by Kingsnorth, Alec (Student) on 15/01/2015.
// Copyright (c) 2015 Kingsnorth, Alec (Student). All rights reserved.
//
#import "CustomCollectionViewCell.h"
@implementation CustomCollectionViewCell
-(void)updateImage:(UIImage*)image withHighlight:(BOOL)isHighlighted andItemNo:(NSInteger)item
{
for (UIView* subview in [self.contentView subviews])
{
[subview removeFromSuperview];
}
// NSLog(@"%d",isHighlighted);
//Image with
self.image=image;
self.imageView=[[UIImageView alloc] initWithFrame:self.contentView.frame];
//NSLog(@"bounds: ",NSStringFromCGRect(self.contentView.frame));
self.imageView.image=image;
self.imageView.hidden=NO;
if (isHighlighted==YES)
{
[_imageView.layer setBorderColor: [[UIColor redColor] CGColor]];
[_imageView.layer setBorderWidth: 2.0];
}
else
{
}
UILabel* label=[[UILabel alloc]initWithFrame:self.contentView.bounds];
label.text=[NSString stringWithFormat:@"%ld",(long)item];
self.imageView.bounds=self.contentView.bounds;
[self.contentView addSubview:self.imageView];
[self.contentView addSubview:label];
}
@end