我正在使用一个自定义的 UITableViewCell,它有一些要显示的标签、按钮和图像视图。单元格中有一个标签,其文本是 NSString
对象,字符串的长度可以是可变的。因此,我无法在 UITableView
的 heightForCellAtIndex
方法中为单元格设置恒定高度。单元格的高度取决于标签的高度,可以使用 NSString
的 sizeWithFont
方法确定。我尝试使用它,但看起来我在某个地方出错了。如何修复?
这是用于初始化单元格的代码。
if (self = [super initWithFrame:frame reuseIdentifier:reuseIdentifier])
{
self.selectionStyle = UITableViewCellSelectionStyleNone;
UIImage *image = [UIImage imageNamed:@"dot.png"];
imageView = [[UIImageView alloc] initWithImage:image];
imageView.frame = CGRectMake(45.0,10.0,10,10);
headingTxt = [[UILabel alloc] initWithFrame: CGRectMake(60.0,0.0,150.0,post_hdg_ht)];
[headingTxt setContentMode: UIViewContentModeCenter];
headingTxt.text = postData.user_f_name;
headingTxt.font = [UIFont boldSystemFontOfSize:13];
headingTxt.textAlignment = UITextAlignmentLeft;
headingTxt.textColor = [UIColor blackColor];
dateTxt = [[UILabel alloc] initWithFrame:CGRectMake(55.0,23.0,150.0,post_date_ht)];
dateTxt.text = postData.created_dtm;
dateTxt.font = [UIFont italicSystemFontOfSize:11];
dateTxt.textAlignment = UITextAlignmentLeft;
dateTxt.textColor = [UIColor grayColor];
NSString * text1 = postData.post_body;
NSLog(@"text length = %d",[text1 length]);
CGRect bounds = [UIScreen mainScreen].bounds;
CGFloat tableViewWidth;
CGFloat width = 0;
tableViewWidth = bounds.size.width/2;
width = tableViewWidth - 40; //fudge factor
//CGSize textSize = {width, 20000.0f}; //width and height of text area
CGSize textSize = {245.0, 20000.0f}; //width and height of text area
CGSize size1 = [text1 sizeWithFont:[UIFont systemFontOfSize:11.0f]
constrainedToSize:textSize lineBreakMode:UILineBreakModeWordWrap];
CGFloat ht = MAX(size1.height, 28);
textView = [[UILabel alloc] initWithFrame:CGRectMake(55.0,42.0,245.0,ht)];
textView.text = postData.post_body;
textView.font = [UIFont systemFontOfSize:11];
textView.textAlignment = UITextAlignmentLeft;
textView.textColor = [UIColor blackColor];
textView.lineBreakMode = UILineBreakModeWordWrap;
textView.numberOfLines = 3;
textView.autoresizesSubviews = YES;
[self.contentView addSubview:imageView];
[self.contentView addSubview:textView];
[self.contentView addSubview:webView];
[self.contentView addSubview:dateTxt];
[self.contentView addSubview:headingTxt];
[self.contentView sizeToFit];
[imageView release];
[textView release];
[webView release];
[dateTxt release];
[headingTxt release];
}
这是高度和宽度出错的标签:
textView = [[UILabel alloc] initWithFrame:CGRectMake(55.0,42.0,245.0,ht)];
您的 UITableViewDelegate
应该实现 tableView:heightForRowAtIndexPath:
Objective-C
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
return [indexPath row] * 20;
}
斯威夫特 5
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return indexPath.row * 20
}
您可能希望使用 NSString
的 sizeWithFont:constrainedToSize:lineBreakMode:
方法来计算行高,而不是仅仅在 indexPath 上执行一些愚蠢的数学运算 :)
如果所有行的高度相同,只需设置 UITableView 的 rowHeight
属性,而不是实现 heightForRowAtIndexPath
。苹果文档:
使用 tableView:heightForRowAtIndexPath: 代替 rowHeight 会影响性能。每次显示表视图时,它都会在委托上为其每一行调用 tableView:heightForRowAtIndexPath:,这可能会导致具有大量行(大约 1000 或更多)的表视图出现严重的性能问题。
tableView.rowHeight
,则不会调用 heightForRowAtIndexPath
,以防您试图找出原因(就像我一样)。
在自定义 UITableViewCell -控制器中添加这个
-(void)layoutSubviews {
CGRect newCellSubViewsFrame = CGRectMake(0, 0, self.frame.size.width, self.frame.size.height);
CGRect newCellViewFrame = CGRectMake(self.frame.origin.x, self.frame.origin.y, self.frame.size.width, self.frame.size.height);
self.contentView.frame = self.contentView.bounds = self.backgroundView.frame = self.accessoryView.frame = newCellSubViewsFrame;
self.frame = newCellViewFrame;
[super layoutSubviews];
}
在 UITableView -controller 添加这个
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
return [indexPath row] * 1.5; // your dynamic height...
}
#define FONT_SIZE 14.0f
#define CELL_CONTENT_WIDTH 300.0f
#define CELL_CONTENT_MARGIN 10.0f
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath;
{
/// Here you can set also height according to your section and row
if(indexPath.section==0 && indexPath.row==0)
{
text=@"pass here your dynamic data";
CGSize constraint = CGSizeMake(CELL_CONTENT_WIDTH - (CELL_CONTENT_MARGIN * 2), 20000.0f);
CGSize size = [text sizeWithFont:[UIFont systemFontOfSize:FONT_SIZE] constrainedToSize:constraint lineBreakMode:UILineBreakModeWordWrap];
CGFloat height = MAX(size.height, 44.0f);
return height + (CELL_CONTENT_MARGIN * 2);
}
else
{
return 44;
}
}
- (UITableViewCell *)tableView:(UITableView *)tv cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell;
UILabel *label = nil;
cell = [tv dequeueReusableCellWithIdentifier:@"Cell"];
if (cell == nil)
{
cell = [[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:@"Cell"];
}
********Here you can set also height according to your section and row*********
if(indexPath.section==0 && indexPath.row==0)
{
label = [[UILabel alloc] initWithFrame:CGRectZero];
[label setLineBreakMode:UILineBreakModeWordWrap];
[label setMinimumFontSize:FONT_SIZE];
[label setNumberOfLines:0];
label.backgroundColor=[UIColor clearColor];
[label setFont:[UIFont systemFontOfSize:FONT_SIZE]];
[label setTag:1];
// NSString *text1 =[NSString stringWithFormat:@"%@",text];
CGSize constraint = CGSizeMake(CELL_CONTENT_WIDTH - (CELL_CONTENT_MARGIN * 2), 20000.0f);
CGSize size = [text sizeWithFont:[UIFont systemFontOfSize:FONT_SIZE] constrainedToSize:constraint lineBreakMode:UILineBreakModeWordWrap];
if (!label)
label = (UILabel*)[cell viewWithTag:1];
label.text=[NSString stringWithFormat:@"%@",text];
[label setFrame:CGRectMake(CELL_CONTENT_MARGIN, CELL_CONTENT_MARGIN, CELL_CONTENT_WIDTH - (CELL_CONTENT_MARGIN * 2), MAX(size.height, 44.0f))];
[cell.contentView addSubview:label];
}
return cell;
}
我看到了很多解决方案,但都是错误的或不完整的。你可以用 viewDidLoad 和 autolayout 中的 5 行来解决所有问题。这对于目标 C:
_tableView.delegate = self;
_tableView.dataSource = self;
self.tableView.estimatedRowHeight = 80;//the estimatedRowHeight but if is more this autoincremented with autolayout
self.tableView.rowHeight = UITableViewAutomaticDimension;
[self.tableView setNeedsLayout];
[self.tableView layoutIfNeeded];
self.tableView.contentInset = UIEdgeInsetsMake(20, 0, 0, 0) ;
对于 Swift 2.0:
self.tableView.estimatedRowHeight = 80
self.tableView.rowHeight = UITableViewAutomaticDimension
self.tableView.setNeedsLayout()
self.tableView.layoutIfNeeded()
self.tableView.contentInset = UIEdgeInsetsMake(20, 0, 0, 0)
现在使用 xib 或在 Storyboard 中的 tableview 中创建单元格有了这个,您无需再实现或覆盖。 (不要忘记数字 os 行 0)和底部标签(约束)降级“Content Hugging Priority -- Vertical to 250”
https://i.stack.imgur.com/65038.png
您可以在下一个 url 中下载代码:https://github.com/jposes22/exampleTableCellCustomHeight
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath;
{
CGSize constraintSize = {245.0, 20000}
CGSize neededSize = [ yourText sizeWithFont:[UIfont systemFontOfSize:14.0f] constrainedToSize:constraintSize lineBreakMode:UILineBreakModeCharacterWrap]
if ( neededSize.height <= 18)
return 45
else return neededSize.height + 45
//18 is the size of your text with the requested font (systemFontOfSize 14). if you change fonts you have a different number to use
// 45 is what is required to have a nice cell as the neededSize.height is the "text"'s height only
//not the cell.
}
要设置行高和估计行高的自动尺寸,请确保执行以下步骤,自动尺寸对单元格/行高布局有效。
分配和实现tableview dataSource和delegate
将 UITableViewAutomaticDimension 分配给 rowHeight 和estimatedRowHeight
实现委托/数据源方法(即 heightForRowAt 并返回一个值 UITableViewAutomaticDimension 给它)
-
目标 C:
// in ViewController.h
#import <UIKit/UIKit.h>
@interface ViewController : UIViewController <UITableViewDelegate, UITableViewDataSource>
@property IBOutlet UITableView * table;
@end
// in ViewController.m
- (void)viewDidLoad {
[super viewDidLoad];
self.table.dataSource = self;
self.table.delegate = self;
self.table.rowHeight = UITableViewAutomaticDimension;
self.table.estimatedRowHeight = UITableViewAutomaticDimension;
}
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
return UITableViewAutomaticDimension;
}
迅速:
@IBOutlet weak var table: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
// Don't forget to set dataSource and delegate for table
table.dataSource = self
table.delegate = self
// Set automatic dimensions for row height
table.rowHeight = UITableViewAutomaticDimension
table.estimatedRowHeight = UITableViewAutomaticDimension
}
// UITableViewAutomaticDimension calculates height of label contents/text
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return UITableViewAutomaticDimension
}
对于 UITableviewCell 中的标签实例
设置行数 = 0(& 换行模式 = 截断尾部)
设置关于其超级视图/单元格容器的所有约束(顶部、底部、左右)。
可选:设置标签的最小高度,如果你想要标签覆盖的最小垂直区域,即使没有数据。
https://i.stack.imgur.com/T354s.png
注意:如果您有多个具有动态长度的标签(UIElements),应根据其内容大小进行调整:为您希望以更高优先级扩展/压缩的标签调整“内容拥抱和压缩阻力优先级”。
在此示例中,我设置了低拥抱和高抗压优先级,这导致为第二个(黄色)标签的内容设置更多优先级/重要性。
https://i.stack.imgur.com/vGRDJ.png
感谢所有关于这个主题的帖子,有一些非常有用的方法可以调整 UITableViewCell 的 rowHeight。
这是其他人的一些概念的汇编,这些概念在为 iPhone 和 iPad 构建时确实很有帮助。您还可以访问不同的部分并根据不同大小的视图进行调整。
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
{
int cellHeight = 0;
if ([indexPath section] == 0)
{
cellHeight = 16;
settingsTable.rowHeight = cellHeight;
}
else if ([indexPath section] == 1)
{
cellHeight = 20;
settingsTable.rowHeight = cellHeight;
}
return cellHeight;
}
else
{
int cellHeight = 0;
if ([indexPath section] == 0)
{
cellHeight = 24;
settingsTable.rowHeight = cellHeight;
}
else if ([indexPath section] == 1)
{
cellHeight = 40;
settingsTable.rowHeight = cellHeight;
}
return cellHeight;
}
return 0;
}
要在 Label 的文本增加时动态单元格高度,首先需要计算高度,文本将在 -heightForRowAtIndexPath
委托方法中使用并返回它与其他标签的添加高度,图像(文本的最大高度 + 高度其他静态组件)并在单元创建中使用相同的高度。
#define FONT_SIZE 14.0f
#define CELL_CONTENT_WIDTH 300.0f
#define CELL_CONTENT_MARGIN 10.0f
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath;
{
if (indexPath.row == 2) { // the cell you want to be dynamic
NSString *text = dynamic text for your label;
CGSize constraint = CGSizeMake(CELL_CONTENT_WIDTH - (CELL_CONTENT_MARGIN * 2), 20000.0f);
CGSize size = [text sizeWithFont:[UIFont systemFontOfSize:FONT_SIZE] constrainedToSize:constraint lineBreakMode:UILineBreakModeWordWrap];
CGFloat height = MAX(size.height, 44.0f);
return height + (CELL_CONTENT_MARGIN * 2);
}
else {
return 44; // return normal cell height
}
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = @"Cell";
UILabel *label;
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier] ;
}
label = [[UILabel alloc] initWithFrame:CGRectMake(10, 5, 280, 34)];
[label setNumberOfLines:2];
label.backgroundColor = [UIColor clearColor];
[label setFont:[UIFont systemFontOfSize:FONT_SIZE]];
label.adjustsFontSizeToFitWidth = NO;
[[cell contentView] addSubview:label];
NSString *text = dynamic text fro your label;
[label setText:text];
if (indexPath.row == 2) {// the cell which needs to be dynamic
[label setNumberOfLines:0];
CGSize constraint = CGSizeMake(CELL_CONTENT_WIDTH - (CELL_CONTENT_MARGIN * 2), 20000.0f);
CGSize size = [text sizeWithFont:[UIFont systemFontOfSize:FONT_SIZE] constrainedToSize:constraint lineBreakMode:UILineBreakModeWordWrap];
[label setFrame:CGRectMake(CELL_CONTENT_MARGIN, CELL_CONTENT_MARGIN, CELL_CONTENT_WIDTH - (CELL_CONTENT_MARGIN * 2), MAX(size.height, 44.0f))];
}
return cell;
}