Increase height of tableview cell according to amount of UILabel text

问题

I want to change the height of my tableview cell according to the amount of text by using auto layout. I have tried the following code but it doesn't work:

    - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{

    AddTaskDetails *addTaskDetail = (self.tasksArray)[indexPath.row];
    CGFloat height;
    float textcount = [addTaskDetail.taskDetail length];
    if(textcount>60)
    {



            height = textcount-20;

        NSLog(@"%d,%f",indexPath.row,height);
    }
    else
    {
        height = 70;
    }
    return height;
}

回答1:

You better don't hardcode the height required for the string. Rather use the attributed text height property.

let attributes = [NSFontAttributeName : textFont,
        NSForegroundColorAttributeName : UIColor(
            red:25/255,
            green:176/255,
            blue:37/255,
            alpha:1.0)]


let attrString:NSAttributedString? = NSAttributedString(string: yourString, attributes: attributes)
let rect:CGRect = attrString!.boundingRectWithSize(CGSizeMake(280.0,CGFloat.max), options: NSStringDrawingOptions.UsesLineFragmentOrigin, context:nil )
return rect.height

回答2:

You will need to use boundingRectWithSize:options:attributes:context on the string to be rendered.

This is a frequently asked question and you may find code snippets when you search for 'UITableViewCell with dynamic height'.

回答3:

Try with this... it will help you.

 NSString *classSubjecttxt =@"Some text";
 CGSize requiredSizeSubjetc =[classSubjecttxt sizeWithFont:[UIFont fontWithName:@"Trebuchet MS" size:12] constrainedToSize:CGSizeMake(labelwidth, CGFLOAT_MAX)];



        int height=YOUR DEFAULT HEIGHT;

         if(requiredSizeSubjetc.height >18){

            height=height-18+ceil(requiredSizeSubjetc.height);
        }

        return height;

回答4:

You don't have to do it programmatically. You can easily do it using Autolayouts in interface builder.

Just add a UITableViewCell to you UITableView
Set its style to custom
Make sure its size in Size inspector is default
Add a UILabel to this cell
Set its Top, Bottom, Left, Right Constraints
In size inspector set preferred width to explict
In attribute inspector set number of lines to "0"

Then add these lines in viewDidLoad()

tableView.estimatedRowHeight = 40.0
tableView.rowHeight = UITableViewAutomaticDimension

Also implement these delegate methods

func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
    return UITableViewAutomaticDimension
}

func tableView(tableView: UITableView, estimatedHeightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
    return 44
}

回答5:

- (CGFloat)getLabelHeight:(NSString*)textvalue
{
    if (![textvalue isEqualToString:@""]) {

        NSString *string=textvalue;

        string = [string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];

        UIFont *font = [UIFont systemFontOfSize:12];
        CGSize constraint = CGSizeMake(SCREENWIDTH/1.0,NSIntegerMax);
        NSDictionary *attributes = @{NSFontAttributeName: font};
        CGRect rect = [string boundingRectWithSize:constraint
                                           options:(NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading)
                                        attributes:attributes
                                           context:nil];

        return rect.size.height;
    }
    else
    {
        return 20;
    }

}

Then You can get size by calling this :

AddTaskDetails *addTaskDetail = (self.tasksArray)[indexPath.row];
    CGFloat textHeight = [self getLabelHeight:[addTaskDetail valueForKey:@"YOURKEY"]];

Here You will get the text size of your text then return it to heightForRowAtIndexPath.

回答6:

First of all you need to calculate height of your label.

You can get dynamic height of your label by calling with below functions:

-(CGFloat)getDynamicHeightOfLabelWithFont:(UIFont *)font withText:(NSString *)text withFrame:(CGRect)initialFrame
{
    UILabel *lblDummy = [[UILabel alloc] initWithFrame:initialFrame];
    lblDummy.font = font;
    lblDummy.lineBreakMode = NSLineBreakByWordWrapping;
    lblDummy.numberOfLines = 0;
    lblDummy.text = text;

    CGRect dummyFrame = initialFrame;

    dummyFrame.size = [lblDummy sizeThatFits:initialFrame.size];
    return dummyFrame.size.height;
}

You need to call this function on heightForRowAtIndexPath and return the height. and you need to set the frame on cellForRowAtIndexPath and set frame to your label.

回答7:

1.Create a custom cell class. Create outlets for label/imageview.

2.Add this method in your custom cell class.

-(void) layoutSubviews
{
 [super layoutSubviews];
 [self.contentView layoutIfNeeded];
 self.yourLabel.preferredMaxLayoutWidth = CGRectGetWidth(self.sentenceLabel.frame);
}

3.In your view controller class,create a property of your custom cell class.

-(DynamicTblVCell *)prototypeCell
 {
  if(!_prototypeCell)
   {
      _prototypeCell = [self.tableView dequeueReusableCellWithIdentifier:@"DynamicTblVCell"];
   }
return _prototypeCell;
 }

4. In your viewDidLoad add these two lines:

self.tableView.estimatedRowHeight = 100.0;
self.tableView.rowHeight = UITableViewAutomaticDimension;

5. And finally do this:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
  {
  static NSString *cellIdentifier = @"DynamicTblVCell";
  UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier forIndexPath:indexPath];

//to configure a cell before it is displayed
 [self configureCell:cell forRowAtIndexPath:indexPath];

 return cell;
 }

-(void)configureCell:(UITableViewCell *)cell forRowAtIndexPath:  (NSIndexPath *)indexPath
 {
  if([cell isKindOfClass:[DynamicTblVCell class]])
   {
    DynamicTblVCell * textCell = (DynamicTblVCell *)cell;
    textCell.sentenceLabel.text = [NSString stringWithFormat:@"jhjshdjshdjhkjdhajsdhajsdh"];
    textCell.sentenceLabel.font = [UIFont preferredFontForTextStyle:UIFontTextStyleBody];  
   }
 }

-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
 {
  [self configureCell:self.prototypeCell forRowAtIndexPath:indexPath];
  self.prototypeCell.bounds = CGRectMake(0.0f, 0.0f, CGRectGetWidth(self.tableView.bounds), CGRectGetHeight(self.prototypeCell.bounds));
  [self.prototypeCell layoutIfNeeded]; 

  CGSize size = [self.prototypeCell.contentView systemLayoutSizeFittingSize:UILayoutFittingCompressedSize];

  return size.height+1;
}


-(CGFloat)tableView:(UITableView *)tableView estimatedHeightForRowAtIndexPath:(NSIndexPath *)indexPath
 {
   return UITableViewAutomaticDimension;
 }

set number of lines for label to 0.
Add constraints for top space, bottom space, left and right space. Do not add height constraint for label.

回答8:

Use below code to get better result with/without Autolayout. Need to calculate font height of label and set the position as per your requirement. Hope for the Best. It will also helpful for calculate collectionView's dynamic cell height.

-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    CGSize constraint = CGSizeMake(screenWidth - 62, 20000.0f);
    CGSize size;
    NSStringDrawingContext *context = [[NSStringDrawingContext alloc] init];
    CGSize boundingBox = [string boundingRectWithSize:constraint
                                              options:NSStringDrawingUsesLineFragmentOrigin
                                           attributes:@{NSFontAttributeName:self.titleLabel.font}
                                              context:context].size;

    size = CGSizeMake(ceil(boundingBox.width), ceil(boundingBox.height));
    return size.height + 16;
}

Let me know if you need more help. :)

来源：https://stackoverflow.com/questions/36544115/increase-height-of-tableview-cell-according-to-amount-of-uilabel-text

标签

ios

objective-c

uitableview

autolayout