ios - 从文档目录获取图像到 Collection View

Question

如何从文档目录中获取图像以填充 Collection View 。到目前为止，我根据我的日志将所有图像转储到每个单元格中，(或者至少图像名称打印在日志中)

首先，我从文档目录 filelist 中获取图像名称是 imageNames.png 的 NSMutable 数组

 NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsPath = [paths objectAtIndex:0];
    NSArray *dirContents = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:documentsPath error:nil];
    fileList=[[NSMutableArray alloc]init];
    for (NSString *filename in dirContents) {
        NSString *fileExt = [filename pathExtension];

        if ([fileExt isEqualToString:@"png"]) {

            [fileList addObject:filename];
        }
    }
    NSLog(@"document folder content list %@ ",fileList);

这会在我的 NSMutsableArray fileList 中返回我的 png 文件名列表。然后我想把所有这些图片放到我的收藏 View 中

//set up cell from nib in viewDidLoad
    UINib *cellNib = [UINib nibWithNibName:@"NibCell" bundle:nil];
    [self.appliancesCollectionView registerNib:cellNib forCellWithReuseIdentifier:@"cvCell"];


     /////


-(NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {

return 1;
}

-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {


return fileList.count;
NSLog(@"collection view count is %@",fileList);

}

-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {

// Setup cell identifier
static NSString *cellIdentifier = @"cvCell";

UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:cellIdentifier forIndexPath:indexPath];


NSString *fileName = [fileList objectAtIndex:indexPath.row];
cell.backgroundView = [[UIImageView alloc] initWithImage: [UIImage imageNamed: fileName]];
NSLog(@"cell Bg image %@",fileList);

return cell;

}


The probelm is nothing shows up in my collection view cells

Answer 1

问题是 contentsOfDirectoryAtPath 返回相对文件路径。你需要绝对。应该使用如下内容:

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsPath = [paths objectAtIndex:0];
NSArray *dirContents = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:documentsPath error:nil];
fileList=[[NSMutableArray alloc]init];

NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]; // NEW LINE 1

for (NSString *filename in dirContents) {
    NSString *fileExt = [filename pathExtension];
    if ([fileExt isEqualToString:@"png"]) {
        NSString *fullPath = [documentsDirectory stringByAppendingPathComponent:filename]; // NEW LINE 2
        [fileList addObject:fullPath]; // NEW LINE 3
    }
}
NSLog(@"document folder content list %@ ",fileList);