UICollectionViewCell 不显示图像 [英] UICollectionViewCell does not show images
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问题描述
如何使用 UICollectionViewCell 获取显示在单元格中的图像?
运行下面所述的代码，我在调试器中得到以下输出.MagazineCell initWithFrame 被调用，当重新加载数据时 setPhoto 被调用.如果我将 setPhoto 代码放在 initWithFrame 方法中，则重新加载将无效.但模拟器只显示灰色单元格.没有添加图片，没有将背景颜色更改为黄色/红色.我错过了什么?
Running the below stated code, I get the following output in the debugger. MagazineCell initWithFrame is called and when reloading the data the setPhoto is called. If I would put the setPhoto code in the initWithFrame method a reload would have no effect.
But the simulator does only show grey cells. No Image added, no backgroundcolor changed to yellow/red. What do I miss?
[5230:70b] -[WebApi getSurroundImages] [Line 326] do surround composition
[5230:70b] -[MagazineCell initWithFrame:] [Line 22] contentView frame: 104.000000
[5230:70b] -[MagazineCell initWithFrame:] [Line 22] contentView frame: 104.000000
[5230:70b] -[MagazineCell initWithFrame:] [Line 22] contentView frame: 104.000000
[5230:70b] -[MagazineCell initWithFrame:] [Line 22] contentView frame: 104.000000
[5230:70b] -[MagazineCell initWithFrame:] [Line 22] contentView frame: 104.000000
[5230:70b] -[MagazineCell initWithFrame:] [Line 22] contentView frame: 104.000000
[5230:70b] -[MagazineCell initWithFrame:] [Line 22] contentView frame: 104.000000
[5230:70b] -[MagazineCell initWithFrame:] [Line 22] contentView frame: 104.000000
[5230:70b] -[MagazineCell initWithFrame:] [Line 22] contentView frame: 104.000000
[5230:70b] -[MagazineCell initWithFrame:] [Line 22] contentView frame: 104.000000
[5230:70b] -[MagazineCell initWithFrame:] [Line 22] contentView frame: 104.000000
[5230:70b] -[MagazineCell initWithFrame:] [Line 22] contentView frame: 104.000000
[5230:70b] -[SurroundViewController didComposition] [Line 146] reload Collection View Data
[5230:70b] -[MagazineCell setPhoto:] [Line 38] height: 104.000000, and width 104.000000
[5230:70b] -[MagazineCell setPhoto:] [Line 38] height: 104.000000, and width 104.000000
[5230:70b] -[MagazineCell setPhoto:] [Line 38] height: 104.000000, and width 104.000000
[5230:70b] -[MagazineCell setPhoto:] [Line 38] height: 104.000000, and width 104.000000
[5230:70b] -[MagazineCell setPhoto:] [Line 38] height: 104.000000, and width 104.000000
[5230:70b] -[MagazineCell setPhoto:] [Line 38] height: 104.000000, and width 104.000000
[5230:70b] -[MagazineCell setPhoto:] [Line 38] height: 104.000000, and width 104.000000
[5230:70b] -[MagazineCell setPhoto:] [Line 38] height: 104.000000, and width 104.000000
[5230:70b] -[MagazineCell setPhoto:] [Line 38] height: 104.000000, and width 104.000000
[5230:70b] -[MagazineCell setPhoto:] [Line 38] height: 104.000000, and width 104.000000
[5230:70b] -[MagazineCell setPhoto:] [Line 38] height: 104.000000, and width 104.000000
[5230:70b] -[MagazineCell setPhoto:] [Line 38] height: 104.000000, and width 104.000000
我是否更改以下内容
// in viewDidLoad
// [self.collectionView registerClass:[MagazineCell class]
// in - collectionView:cellForItemAtIndexPath:indexPath
[mCell.imageView setImageWithURL:photoURL placeholderImage:[UIImage imageNamed:@"foo.jpg"]];
// [mCell setPhoto:photoURL];
我在调试器中得到了以下输出.显示的图像太小，并且没有调用 MagazineCell.不是我想要的
I get the folloing output in the debbuger. The Images are shown, too small, and the MagazineCell is not called. Not that what I want
[5402:70b] -[WebApi getSurroundImages] [Line 326] do surround composition
[5402:70b] -[SurroundViewController didComposition] [Line 146] reload Collection View Data
似乎 imageView 无法正常工作、地址错误或其他问题.但我没有看到我的错误......在完整代码下方:
Seems like the imageView is not working, wrong addressed, or something else. But I do not see my mistake... Below the complete code:
#import <UIKit/UIKit.h>
#import "WebApi.h"
#import "SingletonClass.h"
@interface SurroundViewController : UICollectionViewController <WebApiDelegate>
@property (nonatomic, strong) SingletonClass *sshare;
@property (nonatomic, strong) WebApi *swebapi;
@end
SurroundViewController.m
#import "SurroundViewController.h"
#import "MagazineCell.h"
#import "LazyJoe.h"
#import <AFNetworking/UIImageView+AFNetworking.h>
static NSString * const cellID = @"cellID";
@interface SurroundViewController ()
@property (nonatomic, strong) LazyJoe *lazyJoe;
@end
@implementation SurroundViewController
- (void)viewDidLoad
{
[super viewDidLoad];
self.sshare = [SingletonClass sharedInstance];
self.lazyJoe = [[LazyJoe alloc]init];
self.collectionView.collectionViewLayout = self.lazyJoe; // Layout things are in the Flowlayout
[self.collectionView registerClass:[MagazineCell class] forCellWithReuseIdentifier:cellID];
self.swebapi = [WebApi sharedInstance];
self.swebapi.delegate = self;
[self.swebapi getSurroundImages]; // will call delegate didComposition
}
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
return 1;
}
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
return 10;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
MagazineCell *mCell = (MagazineCell *)[collectionView dequeueReusableCellWithReuseIdentifier:cellID forIndexPath:indexPath];
mCell.backgroundColor = [UIColor lightGrayColor];
NSURL *photoURL = [NSURL URLWithString:self.sshare.coData[indexPath.item]];
//[mCell.imageView setImageWithURL:photoURL placeholderImage:[UIImage imageNamed:@"foo.jpg"]];
[mCell setPhoto:photoURL];
}
return mCell;
}
-(void)didComposition {
DLog(@"reload Collection View Data");
[self.collectionView reloadData];
}
@end
MagazineCell.h
#import <UIKit/UIKit.h>
#import <AFNetworking/UIImageView+AFNetworking.h>
@interface MagazineCell : UICollectionViewCell
@property (weak, nonatomic) IBOutlet UIImageView *imageView;
// is connected to IB with the according CollectionView Cell in the Scene
-(void)setPhoto:(NSURL *)photoURL;
@end
MagazineCell.m
#import "MagazineCell.h"
@implementation MagazineCell
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
self.imageView.frame = self.contentView.frame;
self.imageView.backgroundColor = [UIColor yellowColor];
DLog(@"contentView frame: %f", self.contentView.frame.size.height);
}
return self;
}
-(void)setPhoto:(NSURL *)photoURL {
self.imageView.frame = self.contentView.frame;
DLog(@"height: %f, and width %f", self.frame.size.height, self.contentView.frame.size.width);
self.imageView.backgroundColor = [UIColor redColor];
[self.imageView setImageWithURL:photoURL placeholderImage:[UIImage imageNamed:@"foo.jpg"]];
}
@end
LazyJoe.h
#import <UIKit/UIKit.h>
@interface LazyJoe : UICollectionViewFlowLayout
@end
LazyJoe.m
#import "LazyJoe.h"
@implementation LazyJoe
- (id)init {
if (!(self = [super init])) return nil;
self.itemSize = CGSizeMake(104, 104);
return self;
}
@end
推荐答案
if (imgView != nil) {
dispatch_async(dispatch_get_main_queue(), ^ {
UIButton * imageButton = [UIButton buttonWithType: UIButtonTypeCustom];
imageButton.frame = CGRectMake(-60, -60, 257, 200);
[imageButton setImage: img forState: UIControlStateNormal];
imageButton.tag = [selectorValue intValue];
imageButton.adjustsImageWhenHighlighted = NO;
[imageButton addTarget: self action: @selector(imageViewClicked: ) forControlEvents: UIControlEventTouchUpInside];
[cell addSubview: imageButton];
});
}
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