と を持つストーリーボード アプリがありUIViewControllerますUICollectionViewController。ビュー コントローラーでは、ユーザーは iPhone のフォト ライブラリから複数の写真を選択します (iOS には複数選択用の API がないため、ELCImagePickerControllerを使用してこれを実現しました)。そして、選択した写真を小さな画像ビューで表示する必要があるコレクション ビュー コントローラーに続きます。
画像ライブラリが表示され、複数の写真を選択できます。ただし、コレクション ビュー コントローラーにセグエすると、コレクション ビューのイベントで-[UIImage length]: unrecognized selector sent to instanceエラーがスローされます。cellForItemAtIndexPath
以下は私がこれまでに持っているコードです。
ViewController.h
#import <UIKit/UIKit.h>
#import "ELCImagePickerController.h"
#import "ELCAlbumPickerController.h"
#import "ELCAssetTablePicker.h"
#import "GalleryViewController.h"
@interface ViewController : UIViewController
@property (strong, nonatomic) NSMutableArray *cameraImages;
- (IBAction)chooseImages:(id)sender;
@end
ViewController.m
#import "ViewController.h"
@interface ViewController ()
@end
@implementation ViewController
- (IBAction)chooseImages:(id)sender
{
UIActionSheet *photoSourcePicker = [[UIActionSheet alloc] initWithTitle:nil
delegate:self
cancelButtonTitle:@"Cancel"
destructiveButtonTitle:nil
otherButtonTitles:@"Take Photo", @"Choose from Library", nil, nil];
[photoSourcePicker showInView:self.view];
}
- (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex
{
switch (buttonIndex) {
case 0:
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
ELCAlbumPickerController *albumController = [[ELCAlbumPickerController alloc] initWithNibName:nil bundle:nil];
ELCImagePickerController *elcPicker = [[ELCImagePickerController alloc] initWithRootViewController:albumController];
albumController.parent = elcPicker;
elcPicker.delegate = self;
if ([self.view respondsToSelector:@selector(presentViewController:animated:completion:)]){
[self presentViewController:elcPicker animated:YES completion:nil];
} else {
[self presentViewController:elcPicker animated:YES completion:nil];
}
}
else {
UIAlertView *alert;
alert = [[UIAlertView alloc] initWithTitle:@"Error"
message:@"This device doesn't have a camera"
delegate:self
cancelButtonTitle:@"Ok"
otherButtonTitles:nil, nil];
[alert show];
}
break;
case 1:
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) {
ELCAlbumPickerController *albumController = [[ELCAlbumPickerController alloc] initWithNibName:nil bundle:nil];
ELCImagePickerController *elcPicker = [[ELCImagePickerController alloc] initWithRootViewController:albumController];
albumController.parent = elcPicker;
elcPicker.delegate = self;
if ([self.view respondsToSelector:@selector(presentViewController:animated:completion:)]){
[self presentViewController:elcPicker animated:YES completion:nil];
} else {
[self presentViewController:elcPicker animated:YES completion:nil];
}
}
else {
UIAlertView *alert;
alert = [[UIAlertView alloc] initWithTitle:@"Error"
message:@"This device doesn't support photo libraries"
delegate:self
cancelButtonTitle:@"Ok"
otherButtonTitles:nil, nil];
[alert show];
}
break;
}
}
- (void)elcImagePickerController:(ELCImagePickerController *)picker didFinishPickingMediaWithInfo:(NSArray *)info
{
[self dismissViewControllerAnimated:YES completion:nil];
self.cameraImages = [[NSMutableArray alloc] initWithCapacity:info.count];
for (NSDictionary *camImage in info) {
UIImage *image = [camImage objectForKey:UIImagePickerControllerOriginalImage];
[self.cameraImages addObject:image];
}
/*
for (UIImage *image in info) {
[self.attachImages addObject:image];
}
*/
NSLog(@"number of images = %d", self.cameraImages.count);
if (self.cameraImages.count > 0) {
[self performSegueWithIdentifier:@"toGallery" sender:nil];
}
}
- (void)elcImagePickerControllerDidCancel:(ELCImagePickerController *)picker
{
if ([self respondsToSelector:@selector(dismissViewControllerAnimated:completion:)]) {
[self dismissViewControllerAnimated:YES completion:nil];
} else {
[self dismissViewControllerAnimated:YES completion:nil];
}
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:@"toGallery"]) {
GalleryViewController *galleryVC = [segue destinationViewController];
galleryVC.selectedImages = self.cameraImages;
}
}
@end
GalleryViewController.h
#import <UIKit/UIKit.h>
#import "ELCImagePickerController.h"
#import "ELCAlbumPickerController.h"
#import "ELCAssetTablePicker.h"
#import "ImageCell.h"
@interface GalleryViewController : UICollectionViewController <UIImagePickerControllerDelegate, UINavigationControllerDelegate, UICollectionViewDelegate, UICollectionViewDataSource>
@property (strong, nonatomic) NSMutableArray *selectedImages;
@end
GalleryViewController.m
#import "GalleryViewController.h"
@interface GalleryViewController ()
@end
@implementation GalleryViewController
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{
return 1;
}
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
return self.selectedImages.count;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
ImageCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"imgCell" forIndexPath:indexPath];
UIImage *image;
int row = indexPath.row;
image = [UIImage imageNamed:self.selectedImages[row]]; //This is where it throws the error
cell.imageView.image = image;
return cell;
}
@end
この問題をさらに実証するために、ここからダウンロードできるデモ プロジェクトを作成しました。
このように、ここSOで何度も質問されていることを私は知っています。ここに質問を投稿する前に、それらをすべて試しましたが、役に立ちませんでした。
誰かがこのエラーを取り除く方法を教えていただければ幸いです。
ありがとうございました。