我一直在努力得到这个教程dynamic-cell-height现在在 ios8 中工作了几天,不知道发生了什么。它适用于 iphone 上的 ios7,它适用于 iPAD 上的 ios7 和 ios8,但不适用于 ios8 上的任何 iphone。
我认为问题在于如何以及何时在单元格中创建标签。
我在 Controller 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;
}
在单元格使用的自定义标签中,我有以下内容:
@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,标签似乎是先创建的,然后是单元格边界,然后再次调整标签的大小。但在 ios8 中,我们首先看到内容 View 输出,然后才看到标签的输出。
很抱歉我无法更好地解释它。对我来说,ios 如何制作它的表格有点神秘,所以我真的很困惑为什么它在 ios7 中工作而不是在 ios8 中工作
非常感谢任何帮助。我已经在这里写下了这个问题:Dynamic Cell Height autolayout IOS但我想我在这个问题上引入了关于自动布局的转移注意力。
最佳答案
答案标签的框架错位了。由于没有为 anyXany 安装标签,因此在 Interface Builder 中看不到警告。
因为约束不等于预期高度,所以自动布局无法正确解决 iOS 8 的单元格高度。
快速修复是勾选 anyXany 的已安装框。你会看到警告出现。选择 Answer 标签,选择 Editor->AutoLayout Issues->Update Frames,一切顺利!
更新:
最初显示标签而不需要重新加载的原因是因为勾选了 anyXany 框。 Apple 看到安装了约束,并且初始高度是正确的,无需重新加载或滚动。
如果未勾选此框,则在布局过程中添加约束的时间太晚,导致标签无法具有正确的初始高度。
我建议保留安装单元格的标签(对于任何尺寸类别),因为单元格的约束不会根据特征而改变。
(虽然 tableView 约束确实发生了变化,但单元格的约束不应该是有条件的。如果有一个单元格,它将始终具有相同的约束,无论大小类别如何。)
关于ios - 具有自动布局的 UITableView 中的动态单元格高度,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/30581572/