将目录中保存的图像显示到集合视图

Question

通常当您在项目文件中有图像时，您会使用代码

arraycollectionimages = [[NSArray alloc]]initwithobjects

但是我想显示保存在目录中的图像。我创建了多个目录，所以我只想为其中一个调用图像。为了完成这项工作，我想使用此代码但是我不能这样做？我只是按如下方式将其卡住，但效果不佳。

- (void)viewDidLoad {
    NSArray *arrayCollectionImages = [[NSArray alloc ]init];
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *location=@"Genre1";
    NSString *fPath = [documentsDirectory stringByAppendingPathComponent:location];
    NSArray *directoryContent = [[NSFileManager defaultManager] directoryContentsAtPath: fPath];
    for(NSString *str in directoryContent){
        NSString *finalFilePath = [fPath stringByAppendingPathComponent:str];
        NSData *data = [NSData dataWithContentsOfFile:finalFilePath];
        if(data)
        {
            UIImage *image = [UIImage imageWithData:data];
            [arrayCollectionImages addObject:image];
        }
    }

Answer 1

我认为您的目录搜索可能需要很长时间。试试这个...

        - (void)viewDidLoad {
            dispatch_queue_t searchQ = dispatch_queue_create("com.awesome", 0);
            dispatch_async(searchQ, ^{
            NSArray *arrayCollectionImages = [[NSArray alloc ]init];
            NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
            NSString *documentsDirectory = [paths objectAtIndex:0];
            NSString *location=@"Genre1";
            NSString *fPath = [documentsDirectory stringByAppendingPathComponent:location];
            NSArray *directoryContent = [[NSFileManager defaultManager] directoryContentsAtPath: fPath];
            for(NSString *str in directoryContent){
                NSString *finalFilePath = [fPath stringByAppendingPathComponent:str];
                NSData *data = [NSData dataWithContentsOfFile:finalFilePath];
                if(data)
                {   dispatch_async(dispatch_get_main_queue(),^{
                    UIImage *image = [UIImage imageWithData:data];
                    });
                    [arrayCollectionImages addObject:image];
                }
            }
    });

}

代码基本上会在搜索中产生另一个线程，并在图像准备好时放置图像。