Question

所以我通过将调整大小的图像放入其中来进行第一次UIScrollview，但是当我到达第一组结果并添加第二组等时，视图将重置为开头。我不确定它是否正在添加图像，因为x值正在向前计数，因此UIScrollview应该调整大小，所以我只能假设它只是将下一组图像放在旧图像之上。

我在这里做错了什么？

-(void)addScrollViewImages {
    // setup our UIScrollview
    self.scrollView.delegate = self;
    self.scrollView.pagingEnabled = YES;
    self.scrollView.showsHorizontalScrollIndicator = NO;
    self.scrollView.showsVerticalScrollIndicator = NO;
    self.scrollView.contentSize = CGSizeMake(self.scrollView.frame.size.width,self.scrollView.frame.size.height);

    // hit our server for the data
    NSString *encodedKeywords =[self.keyword stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
    self.results = [self fetchImageResults:encodedKeywords];

    // loop over some image results
    for (id image in self.results)
    {
        UIImageView *imageView = [[UIImageView alloc] initWithFrame: CGRectMake(self.x, 0, self.screenWidth, self.screenHight)];

        NSString *imageUrl = image[@"url"];
        NSData *image = [NSData dataWithContentsOfURL:[NSURL URLWithString:imageUrl]];

        // resize the image to the device
        [imageView setImage:[self imageScaleCropToSize:[UIImage imageWithData:image]]];

        [self.scrollView addSubview: imageView];
        self.x = (self.x + imageView.frame.size.width);

        // resize frame width
        if(self.x > self.view.frame.size.width) self.scrollView.contentSize = CGSizeMake(self.x, self.scrollView.frame.size.height);
    }
}
// This just gets the json data and processes it a little
-(NSArray*)fetchImageResults:(NSString*)keyword {
    //This should be fairly quick
    NSError *error = nil;
    NSURL *apiURL = [NSURL URLWithString:[NSString stringWithFormat:@"http://example.com/api/v1/search?q=%@", keyword]];
    NSData *jsonData = [NSData dataWithContentsOfURL:apiURL];
    NSDictionary *result = [NSJSONSerialization JSONObjectWithData:jsonData options:0 error:&error];
    return result[@"results"];
}
// Scroll index management
- (void)scrollViewDidScroll:(UIScrollView *)sender {
    float indexNum = self.scrollView.contentOffset.x / self.scrollView.frame.size.width;
    if(floor(indexNum) == indexNum) {
        int num = (int)indexNum;

        NSLog(@"viewing %@",self.results[num]);

        // if we are at the end, load more
        if(num == (self.results.count-1) ) {
            dispatch_async(dispatch_get_main_queue(), ^{
                [self addScrollViewImages];
            });
        }
    }
}

Answer 1

你没有使用UITableView就自杀了。只需使用原型UITableView制作UITableViewCells即可。对单元格imageViewTableCell进行子类化，并使其唯一属性为UIImageView，填充其大小。

其余的只是使用UITableViewDelegate和UITableViewDataSource。

Tutorial for setting up a tableview

Answer 2

我明白了。

首先，我从未在viewDidLoad方法的开头启动结果NSMutableArray

    self.results = [[NSMutableArray alloc] init];

一旦我改变了，我所要做的就是更新我的滚动方法

// Scroll index management
- (void)scrollViewDidScroll:(UIScrollView *)sender {
    float indexNum = self.scrollView.contentOffset.x / self.scrollView.frame.size.width;
    float currentPosition = self.scrollView.contentOffset.x;

    if(floor(indexNum) == indexNum) {
        int num = (int)indexNum;
        // if we are at the end, load more
        if(num == ([self.results count]-1)) {
            dispatch_async(dispatch_get_main_queue(), ^{
                [self addScrollViewImages];
                [self.scrollView setContentOffset:CGPointMake(currentPosition, 0.0)];
            });
        }
    }
}

使用水平无限样式滚动将图像添加到UIScrollview

2 个答案: