iPad App的iOS自定义网格视图可显示下载的图像

Question

add an object of type collection view then make a proper connection through collection inspector.

in .h file

IBOutlet UICollectionView   *myCollection;

in viewdidload

 myCollection.delegate = self;
myCollection.dataSource = self;

and the data source / delegate methods are :

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:   (NSInteger)section
{
return 15;
}

 // The cell that is returned must be retrieved from a call to -  dequeueReusableCellWithReuseIdentifier:forIndexPath:
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView  cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
UICollectionViewCell * cell = [collectionView  dequeueReusableCellWithReuseIdentifier:@"CellID" forIndexPath:indexPath];

cell.backgroundColor=[UIColor greenColor];

return cell;
}

- (CGSize)collectionView:(UICollectionView *)collectionView layout: (UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *  )indexPath
{
return CGSizeMake(100, 100);
}

-(void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:  (NSIndexPath *)indexPath
{

}

getting this error

could not dequeue a view of kind: UICollectionElementKindCell with identifier CellID -   must register a nib or a class for the identifier or connect a prototype cell in a   storyboard'

what should i do now… please help me to resolve it..

Answer 1

You can use UICollectionView to show grid view in iOS.

For Example:

In HAViewController.h

#import <UIKit/UIKit.h>

@interface HACollectionCell : UICollectionViewCell

@end

@interface HAViewController : UIViewController <UICollectionViewDataSource, UICollectionViewDelegate>

@end

in HAViewController.m

#import "HAViewController.h"    

@implementation HACollectionCell


@end

@implementation HAViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    UICollectionViewFlowLayout *layout=[[UICollectionViewFlowLayout alloc] init];

    UICollectionView * collectionView = [[UICollectionView alloc] initWithFrame:CGRectMake(0.0, 0.0, self.view.frame.size.width, self.view.frame.size.width) collectionViewLayout:layout];

    collectionView.delegate = self;

    collectionView.dataSource = self;

    [collectionView registerClass:[HACollectionCell class] forCellWithReuseIdentifier:@"CellID"];

    [self.view addSubview:collectionView];

    collectionView = nil;
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
    return 15;
}

// The cell that is returned must be retrieved from a call to -dequeueReusableCellWithReuseIdentifier:forIndexPath:
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    UICollectionViewCell * cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"CellID" forIndexPath:indexPath];

    cell.backgroundColor=[UIColor greenColor];

    return cell;
}

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
    return CGSizeMake(100, 100);
}

-(void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath
{

}

@end

Thanks!