[英]dynamic cell height in UITableView with AutoLayout
我一直在尝试使本教程dynamic-cell-height在ios8中运行几天,并且无法弄清楚发生了什么。 它可以在iphone上的ios7中工作,并且可以在iPAD上的ios7和ios8中工作,但不适用于ios8上的任何iphone。
我认为问题在于在单元中如何以及何时创建标签。
我在控制器中有以下代码:
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
self.dbManager = [[DBManager alloc] initWithDatabaseFilename:@"tomhaisdb.sql"];
[self loadData];
}
-(void)viewWillAppear:(BOOL)animated{
[super viewWillAppear:animated];
[self deselectAllRows];
}
-(void)deselectAllRows{
for (NSIndexPath * indexPath in [self.tableView indexPathsForSelectedRows]) {
[self.tableView deselectRowAtIndexPath:indexPath animated:NO];
}
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(void)loadData {
NSString *query = @"select * from favourites";
if (self.favourites != nil) {
self.favourites = nil;
}
self.favourites = [[NSArray alloc] initWithArray:[self.dbManager loadDataFromDB:query]];
/* [self reloadDataWithCompletions:^{
self.tableView.backgroundColor = [UIColor colorWithRed:28.0f/255.0f green:30.0f/255.0f blue:35.0f/255.0f alpha:1];
}];*/
[self reloadTableViewContent];
}
- (void)reloadTableViewContent {
dispatch_async(dispatch_get_main_queue(), ^{
[self.tableView reloadData];
[self.tableView scrollRectToVisible:CGRectMake(0, 0, 1, 1) animated:NO];
});
}
/*-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{
return 1;
}*/
#pragma mark - UITableViewDataSource
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
NSLog(@"Number of rows: %d", self.favourites.count);
return self.favourites.count;
}
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
return [self basicCellAtIndexPath:indexPath];
}
-(favouritedCell *)basicCellAtIndexPath:(NSIndexPath *)indexPath {
favouritedCell *cell = [self.tableView dequeueReusableCellWithIdentifier:@"favouriteCell" forIndexPath:indexPath];
[self configureBasicCell:cell atIndexPath:indexPath];
return cell;
}
-(void)configureBasicCell:(favouritedCell *)cell atIndexPath:(NSIndexPath *)indexPath{
NSInteger indexOfTomhaisText = [self.dbManager.arrColumnNames indexOfObject:@"tomhaisText"];
NSString *tomhaisText = [[self.favourites objectAtIndex:indexPath.row] objectAtIndex:indexOfTomhaisText];
[self setTomhaisForCell:cell item:tomhaisText];
[self setAnswerForCell:cell item:tomhaisText]; // change this later
}
-(void)setTomhaisForCell:(favouritedCell *)cell item:(NSString *)item{
[cell.favouriteText setText:item];
}
-(void)setAnswerForCell:(favouritedCell *)cell item:(NSString *)item{
[cell.answer setText:item];
}
#pragma mark - UITableViewDelegate
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
/* if ([[[UIDevice currentDevice]systemVersion]floatValue] >= 8.0) {
return UITableViewAutomaticDimension;
}
else{*/
return [self heightForFavouriteCellAtIndexPath:indexPath];
/*}*/
}
-(CGFloat)heightForFavouriteCellAtIndexPath:(NSIndexPath *)indexPath{
static favouritedCell *sizingCell = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sizingCell = [self.tableView dequeueReusableCellWithIdentifier:@"favouriteCell"];
});
[self configureBasicCell:sizingCell atIndexPath:indexPath];
return [self calculateHeightForConfiguredSizingCell:sizingCell];
}
-(CGFloat)calculateHeightForConfiguredSizingCell:(UITableViewCell *)sizingCell{
sizingCell.bounds = CGRectMake(0.0f, 0.0f, CGRectGetWidth(self.tableView.frame), CGRectGetHeight(sizingCell.bounds));
NSLog(@"Bounds before Layout %@", NSStringFromCGRect(sizingCell.bounds));
NSLog(@"Content View before Layout %@", NSStringFromCGRect(sizingCell.contentView.bounds));
[sizingCell setNeedsLayout];
[sizingCell layoutIfNeeded];
CGSize size = [sizingCell.contentView systemLayoutSizeFittingSize:UILayoutFittingCompressedSize];
NSLog(@"Bounds after layout %@", NSStringFromCGRect(sizingCell.bounds));
NSLog(@"Content View before Layout %@", NSStringFromCGRect(sizingCell.contentView.bounds));
return size.height + 1.0f;
}
-(CGFloat)tableView:(UITableView *)tableView estimatedHeightForRowAtIndexPath:(NSIndexPath *)indexPath{
return 155.0f;
}
在自定义标签中,单元格使用以下内容:
@implementation favouriteLabel
- (void)setBounds:(CGRect)bounds {
[super setBounds:bounds];
// If this is a multiline label, need to make sure
// preferredMaxLayoutWidth always matches the frame width
// (i.e. orientation change can mess this up)
if (self.numberOfLines == 0 && bounds.size.width != self.preferredMaxLayoutWidth) {
self.preferredMaxLayoutWidth = self.bounds.size.width;
NSLog(@"Label Bounds before update constraints %@", NSStringFromCGRect(self.bounds));
[self setNeedsUpdateConstraints];
NSLog(@"Label Bounds after update constraints %@", NSStringFromCGRect(self.bounds));
}
}
@end
我认为我的问题在于创建标签时的原因是因为在ios 7中我得到了如下输出:
2015-06-01 20:07:10.563 Facts[63322:607] Label Bounds before update constraints {{0, 0}, {216, 2}}
2015-06-01 20:07:10.563 Facts[63322:607] Label Bounds after update constraints {{0, 0}, {216, 2}}
2015-06-01 20:07:10.563 Facts[63322:607] Label Bounds before update constraints {{0, 0}, {217, 40}}
2015-06-01 20:07:10.563 Facts[63322:607] Label Bounds after update constraints {{0, 0}, {217, 40}}
>2015-06-01 20:07:10.564 Facts[63322:607] Bounds after layout {{0, 0}, {256, 82}}
2015-06-01 20:07:10.564 Facts[63322:607] Content View before Layout {{0, 0}, {256, 82}}
2015-06-01 20:07:10.564 Facts[63322:607] Bounds before Layout {{0, 0}, {256, 82}}
2015-06-01 20:07:10.564 Facts[63322:607] Content View before Layout {{0, 0}, {256, 82}}
2015-06-01 20:07:10.565 Facts[63322:607] Bounds after layout {{0, 0}, {256, 82}}
2015-06-01 20:07:10.565 Facts[63322:607] Content View before Layout {{0, 0}, {256, 82}}
2015-06-01 20:07:10.569 Facts[63322:607] Label Bounds before update constraints {{0, 0}, {216, 74.5}}
2015-06-01 20:07:10.569 Facts[63322:607] Label Bounds after update constraints {{0, 0}, {216, 74.5}}
2015-06-01 20:07:10.569 Facts[63322:607] Label Bounds before update constraints {{0, 0}, {217, 40}}
2015-06-01 20:07:10.570 Facts[63322:607] Label Bounds after update constraints {{0, 0}, {217, 40}}
但是在ios8中,输出是不同的。
2015-06-01 20:18:06.049 Facts[63396:81689795] Bounds before Layout {{0, 0}, {256, 44}}
2015-06-01 20:18:06.049 Facts[63396:81689795] Content View before Layout {{0, 0}, {320, 44}}
2015-06-01 20:18:06.131 Facts[63396:81689795] Label Bounds before update constraints {{0, 0}, {216, 0}}
2015-06-01 20:18:06.131 Facts[63396:81689795] Label Bounds after update constraints {{0, 0}, {216, 0}}
2015-06-01 20:18:06.131 Facts[63396:81689795] Label Bounds before update constraints {{0, 0}, {217, 4.5}}
2015-06-01 20:18:06.131 Facts[63396:81689795] Label Bounds after update constraints {{0, 0}, {217, 4.5}}
在ios7中,似乎首先创建了标签,然后创建了单元边界,然后再次调整了标签的大小。 但是在ios8中,我们首先看到内容视图的输出,然后才看到标签的输出。
对不起,我再也无法解释了。 ios如何使它成为表格对我来说还是个谜,所以我真的对为什么它在ios7中而不是在ios8中起作用深感困惑
任何帮助,不胜感激。 我已经在这里写下了这个问题: 动态单元高度自动布局IOS,但我认为我对该问题的自动布局大加赞赏。
框架放错了答案标签。 由于未为anyXany安装标签,因此该警告在Interface Builder中不可见。
由于约束条件不等于预期的高度,因此自动布局无法正确解决iOS 8的单元格高度。
快速解决方案是在anyXany的“已安装”框中打勾。 您会看到警告显示。 选择“答案”标签,然后选择“编辑器”->“自动版式问题”->“更新框架”,一切顺利!
更新:
标签最初显示而无需重新加载的原因是因为anyXany框已被打勾。 Apple看到安装了约束,并且初始高度正确,没有重新加载或滚动。
如果未选中该框,则约束在布局过程中添加得太晚,以使标签具有正确的初始高度。
我建议您保留单元格的标签(对于任何大小级别),因为单元格的约束不会改变,这取决于特征。
(虽然制约的tableView做改变,细胞的限制不应该是有条件的。如果有一个细胞,它总是有相同的限制,不论级别大小。)
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