UITableView 中的 UIScrollView 中的 ContentOffset 问题
ContentOffset issue in UIScrollView in UITableView
我在 UITableView 的每个 UITableViewCell 中添加了一个 UIScrollView。
这是我的代码。
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString* CellIdentifier = @"Cell";
UITableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
UIScrollView *propertyScrollView;
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
propertyScrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, tableView.frameWidth, 100)];
[propertyScrollView setContentSize:CGSizeMake(10*tableView.frameWidth, 100)];
[propertyScrollView setPagingEnabled:YES];
propertyScrollView.delegate = self;
propertyScrollView.tag = indexPath.row;
[[cell contentView] addSubview:propertyScrollView];
propertyScrollView.backgroundColor = [UIColor blackColor];
int pagingIndex = [[m_pagingIndexArray objectAtIndex:indexPath.row]intValue];
[propertyScrollView setContentOffset:CGPointMake(pagingIndex*propertyScrollView.frameWidth, 0)];
for(int i=0;i<10;i++)
{
UIButton *singleImage = [[UIButton alloc]initWithFrame:CGRectMake(i*tableView.frameWidth, 0, propertyScrollView.frameWidth, propertyScrollView.frameHeight)];
[propertyScrollView addSubview:singleImage];
singleImage.titleLabel.text = [NSString stringWithFormat:@"%d",i];
singleImage.titleLabel.textColor = [UIColor blackColor];
singleImage.titleLabel.font = systemFontBoldTypeOfSize(20);
[singleImage setImage:[horizentalImagesArray objectAtIndex:i] forState:UIControlStateNormal];
singleImage.backgroundColor = [UIColor whiteColor];
}
else
{
propertyScrollView.tag = indexPath.row;
int pagingIndex = [[m_pagingIndexArray objectAtIndex:indexPath.row]intValue];
[propertyScrollView setContentOffset:CGPointMake(pagingIndex*propertyScrollView.frameWidth, 0)];
}
return cell;
}
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
int pageIndex = scrollView.contentOffset.x/scrollView.frameWidth;
[m_pagingIndexArray replaceObjectAtIndex:scrollView.tag withObject:[NSString stringWithFormat:@"%d",pageIndex]];
}
- (void)viewDidLoad {
[super viewDidLoad];
m_pagingIndexArray = [[NSMutableArray alloc]init];
for(int i=0;i<10;i++)
{
[m_pagingIndexArray addObject:@"0"];
}
}
我在单个 UIScrollView(启用分页)中添加 10 个 UIButton。
问题是,如果我滚动任何一个 UITableViewCell 的滚动视图并移动到底部单元格,我可以看到其他一些 UITableViewCell 的滚动视图也滚动到该内容偏移点。
我希望我所有的 UITableview 单元格的 UIScrollView 独立滚动。我怎样才能实现它?请帮我解决这个问题。
如果单元格未被重用,您的代码是正确的,但由于单元格被重用,如果它们被重用,您需要为每个单元格的滚动视图设置内容偏移量。
你需要写一个else case -
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
if(cell == nil)
{
// your code
}
else
{
// reset the content offset of the scroll view as per your needs for the reused cells
}
return cell;
}
您将当前页码保留在 m_pagingIndexArray 中,并且所有单元格都使用相同的数组,因此假设它包含的页码为 3,那么它将适用于所有单元格.
如果像我在下面添加的那样被重复使用,您还需要为每个单元格重置每个按钮的文本和图像-
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell* cell = nil;
UIScrollView *propertyScrollView;
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
propertyScrollView = [[[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, tableView.frameWidth, 100)] autorelease];
[propertyScrollView setContentSize:CGSizeMake(10*tableView.frameWidth, 100)];
[propertyScrollView setPagingEnabled:YES];
propertyScrollView.delegate = self;
propertyScrollView.tag = indexPath.row;
[[cell contentView] addSubview:propertyScrollView];
propertyScrollView.backgroundColor = [UIColor blackColor];
int pagingIndex = [[m_pagingIndexArray objectAtIndex:indexPath.row]intValue];
[propertyScrollView setContentOffset:CGPointMake(pagingIndex*propertyScrollView.frameWidth, 0)];
for(int i=0;i<10;i++)
{
UIButton *singleImage = [[[UIButton alloc]initWithFrame:CGRectMake(i*tableView.frameWidth, 0, propertyScrollView.frameWidth, propertyScrollView.frameHeight)] autorelease];
[propertyScrollView addSubview:singleImage];
singleImage.titleLabel.text = [NSString stringWithFormat:@"%d",i];
singleImage.titleLabel.textColor = [UIColor blackColor];
singleImage.titleLabel.font = systemFontBoldTypeOfSize(20);
[singleImage setImage:[horizentalImagesArray objectAtIndex:i] forState:UIControlStateNormal];
singleImage.backgroundColor = [UIColor whiteColor];
}
return cell;
}
我在 UITableView 的每个 UITableViewCell 中添加了一个 UIScrollView。
这是我的代码。
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString* CellIdentifier = @"Cell";
UITableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
UIScrollView *propertyScrollView;
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
propertyScrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, tableView.frameWidth, 100)];
[propertyScrollView setContentSize:CGSizeMake(10*tableView.frameWidth, 100)];
[propertyScrollView setPagingEnabled:YES];
propertyScrollView.delegate = self;
propertyScrollView.tag = indexPath.row;
[[cell contentView] addSubview:propertyScrollView];
propertyScrollView.backgroundColor = [UIColor blackColor];
int pagingIndex = [[m_pagingIndexArray objectAtIndex:indexPath.row]intValue];
[propertyScrollView setContentOffset:CGPointMake(pagingIndex*propertyScrollView.frameWidth, 0)];
for(int i=0;i<10;i++)
{
UIButton *singleImage = [[UIButton alloc]initWithFrame:CGRectMake(i*tableView.frameWidth, 0, propertyScrollView.frameWidth, propertyScrollView.frameHeight)];
[propertyScrollView addSubview:singleImage];
singleImage.titleLabel.text = [NSString stringWithFormat:@"%d",i];
singleImage.titleLabel.textColor = [UIColor blackColor];
singleImage.titleLabel.font = systemFontBoldTypeOfSize(20);
[singleImage setImage:[horizentalImagesArray objectAtIndex:i] forState:UIControlStateNormal];
singleImage.backgroundColor = [UIColor whiteColor];
}
else
{
propertyScrollView.tag = indexPath.row;
int pagingIndex = [[m_pagingIndexArray objectAtIndex:indexPath.row]intValue];
[propertyScrollView setContentOffset:CGPointMake(pagingIndex*propertyScrollView.frameWidth, 0)];
}
return cell;
}
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
int pageIndex = scrollView.contentOffset.x/scrollView.frameWidth;
[m_pagingIndexArray replaceObjectAtIndex:scrollView.tag withObject:[NSString stringWithFormat:@"%d",pageIndex]];
}
- (void)viewDidLoad {
[super viewDidLoad];
m_pagingIndexArray = [[NSMutableArray alloc]init];
for(int i=0;i<10;i++)
{
[m_pagingIndexArray addObject:@"0"];
}
}
我在单个 UIScrollView(启用分页)中添加 10 个 UIButton。
问题是,如果我滚动任何一个 UITableViewCell 的滚动视图并移动到底部单元格,我可以看到其他一些 UITableViewCell 的滚动视图也滚动到该内容偏移点。
我希望我所有的 UITableview 单元格的 UIScrollView 独立滚动。我怎样才能实现它?请帮我解决这个问题。
如果单元格未被重用,您的代码是正确的,但由于单元格被重用,如果它们被重用,您需要为每个单元格的滚动视图设置内容偏移量。
你需要写一个else case -
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
if(cell == nil)
{
// your code
}
else
{
// reset the content offset of the scroll view as per your needs for the reused cells
}
return cell;
}
您将当前页码保留在 m_pagingIndexArray 中,并且所有单元格都使用相同的数组,因此假设它包含的页码为 3,那么它将适用于所有单元格.
如果像我在下面添加的那样被重复使用,您还需要为每个单元格重置每个按钮的文本和图像-
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell* cell = nil;
UIScrollView *propertyScrollView;
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
propertyScrollView = [[[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, tableView.frameWidth, 100)] autorelease];
[propertyScrollView setContentSize:CGSizeMake(10*tableView.frameWidth, 100)];
[propertyScrollView setPagingEnabled:YES];
propertyScrollView.delegate = self;
propertyScrollView.tag = indexPath.row;
[[cell contentView] addSubview:propertyScrollView];
propertyScrollView.backgroundColor = [UIColor blackColor];
int pagingIndex = [[m_pagingIndexArray objectAtIndex:indexPath.row]intValue];
[propertyScrollView setContentOffset:CGPointMake(pagingIndex*propertyScrollView.frameWidth, 0)];
for(int i=0;i<10;i++)
{
UIButton *singleImage = [[[UIButton alloc]initWithFrame:CGRectMake(i*tableView.frameWidth, 0, propertyScrollView.frameWidth, propertyScrollView.frameHeight)] autorelease];
[propertyScrollView addSubview:singleImage];
singleImage.titleLabel.text = [NSString stringWithFormat:@"%d",i];
singleImage.titleLabel.textColor = [UIColor blackColor];
singleImage.titleLabel.font = systemFontBoldTypeOfSize(20);
[singleImage setImage:[horizentalImagesArray objectAtIndex:i] forState:UIControlStateNormal];
singleImage.backgroundColor = [UIColor whiteColor];
}
return cell;
}