如何计算字符串的高度？

I am trying to adjust the cell height resize to fit the UILabel text, but it is not working..

我试图调整单元格高度调整大小以适应UILabel文本，但它不工作..

var mySize = CGFloat()
    func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCellWithReuseIdentifier("cell", forIndexPath: indexPath) as! cellView

        cell.myLabel.text = self.items[indexPath.item]
        cell.myLabel.bounds.size.height = self.mySize

        cell.backgroundColor = UIColor.yellowColor()

        return cell
    }

    func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
        // handle tap events
        print("You selected cell #\(indexPath.item)!")
    }

    func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {

        func heightForLabel(text:String, font:UIFont, width:CGFloat) -> CGFloat
        {
            let label:UILabel = UILabel(frame: CGRectMake(0, 0, width, CGFloat.max))
            label.numberOfLines = 0
            label.lineBreakMode = NSLineBreakMode.ByWordWrapping
            label.font = font
            label.text = items[indexPath.row]

            label.sizeToFit()
            return label.frame.height
        }

        let font = UIFont(name: "Helvetica Neue", size: 30)
        let detailHeight = heightForLabel(items[indexPath.row], font: font!, width: UIScreen.mainScreen().bounds.size.width)

        self.mySize = detailHeight

        return CGSizeMake(UIScreen.mainScreen().bounds.size.width, 358 + detailHeight)
    }

Any suggestions what to do here? Should i do it another way? Please, I need help.. The problem is that the UILabel text is set in the cellForItemAtIndexPath, and items is an array for strings.

有什么建议在这做什么？我应该用另一种方式吗？请问我需要帮助..问题是UILabel文本是在cellForItemAtIndexPath中设置的，而items是一个字符串数组。

This is my project file, if someone watch to take a look at it: http://www.filedropper.com/test_37

这是我的项目文件，如果有人注意看看它：http：//www.filedropper.com/test_37

7 个解决方案

#1

Why not try this in ObjC

为什么不在ObjC中尝试这个

 [text boundingRectWithSize:CGSizeMake(maxWidth, maxHeight)
                                  options:NSStringDrawingUsesLineFragmentOrigin
                               attributes:nil context:nil]

This will give CGRect. Get the height from it. set font size etc in attributes parameter.

这将给CGRect。从它获得高度。在attributes参数中设置字体大小等。

UPDATE

UPDATE

In place of this

取而代之

let detailHeight = heightForLabel(items[indexPath.row], font: font!, width: UIScreen.mainScreen().bounds.size.width)

Use this

用这个

let height = items[indexPath.row].boundingRectWithSize(CGSizeMake(CGFloat.max,UIScreen.mainScreen().bounds.size.width), options: .UsesLineFragmentOrigin, attributes: [NSFontAttributeName: font!], context: nil).size.height

Hope this helps

希望这可以帮助

#2

You can do it like that but I have implemented it in different way. Here is the sample of code you can do it.

你可以这样做，但我已经以不同的方式实现了它。以下是您可以执行的代码示例。

 let desiredWidth: CGFloat = tableView.bounds.size.width
 let label: UILabel = UILabel()

 let desiredString = "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged."

 label.text = desiredString
 label.numberOfLines = 0;
 label.lineBreakMode = NSLineBreakMode.ByWordWrapping
 let size: CGSize = label.sizeThatFits(CGSizeMake(desiredWidth, CGFloat.max))

 print("Label height you can set to your cell: \(size.height)")

#3

I create this method for getting height of a label. You need to provide label's static Width and label's font

我创建了这个方法来获取标签的高度。您需要提供标签的静态宽度和标签的字体

func dynamicHeight(font: UIFont, width: CGFloat) -> CGFloat{
    let calString = NSString(string: self)
    let textSize = calString.boundingRectWithSize(CGSizeMake(width, CGFloat.max), options: NSStringDrawingOptions.UsesLineFragmentOrigin|NSStringDrawingOptions.UsesFontLeading, attributes: [NSFontAttributeName: font], context: nil)
    return textSize.height
}

#4

Try this...

尝试这个...

   NSString *yourText = @"Your string";
    CGSize lableWidth = CGSizeMake(300, CGFLOAT_MAX);
    CGSize requiredSize = [yourText sizeWithFont:[UIFont fontWithName:@"CALIBRI" size:17] constrainedToSize:lableWidth lineBreakMode:NSLineBreakByWordWrapping];
    int calculatedHeight = requiredSize.height;
    return (float)calculatedHeight;

#5

I took a look at your code, and I was able to solve it.

我看了你的代码，我能够解决它。

Firstly, on line 71 in your ViewController class:

首先，在ViewController类的第71行：

let height = items[indexPath.row].boundingRectWithSize(CGSizeMake(CGFloat.max, UIScreen.mainScreen().bounds.size.width), options: .UsesLineFragmentOrigin, attributes: [NSFontAttributeName: font!], context: nil).size.height

You accidentally set CGFloat.max as width and the width as height. It should be:

您不小心将CGFloat.max设置为宽度，将宽度设置为高度。它应该是：

CGSizeMake(UIScreen.mainScreen().bounds.size.width, CGFloat.max)

I'd say it's better practice to use the width of the view that the cell is directly contained in (the collectionView), but that's just my personal opinion.

我想说使用单元格直接包含在（collectionView）中的视图宽度是更好的做法，但这只是我个人的看法。

Secondly, you need to enable AutoLayout. Go to your Main.storyboard file and make sure Use Auto Layout is selected.

其次，您需要启用AutoLayout。转到Main.storyboard文件，确保选中“使用自动布局”。

Now you need to add constraints. (You can read more about AutoLayout and constraints here)

现在您需要添加约束。（您可以在此处阅读有关AutoLayout和约束的更多信息）

There are different ways to add constraints. The easiest way is to control click a UI element and drag the mouse to the element you want to set a constraint to.

有不同的方法来添加约束。最简单的方法是控制单击UI元素并将鼠标拖动到要设置约束的元素。

You need to add the following constraints for your cell:

您需要为您的单元格添加以下约束：

ImageView.top = cell.top
ImageView.leading = cell.leading
ImageView.trailing = cell.trailing
ImageView.bottom = MyLabel.top + 8 (your padding)
MyLabel.leading = cell.leading
MyLabel.trailing = cell.trailing
MyLabel.bottom = cell.bottom

And these for your CollectionView

这些适用于您的CollectionView

CollectionView.top = view.top
CollectionView.leading = view.leading
CollectionView.trailing = view.trailing
CollectionView.bottom = view.bottom

I've attached the project, modified with AutoLayout here below.

我已经附加了项目，使用下面的AutoLayout进行了修改。

Modified project

修改项目

Edit:

编辑：

Approach 2 - without AutoLayout.

方法2 - 没有AutoLayout。

This could also be achieved without using AutoLayout by manually updating the cell's label height in collectionView:willDisplayCell:. I'm sure there are better alternatives, I'd personally try AutoResizingMasks before this approach.

这也可以通过在collectionView：willDisplayCell：中手动更新单元格的标签高度而不使用AutoLayout来实现。我确信有更好的选择，我会在这种方法之前亲自尝试AutoResizingMasks。

Project without AutoLayout

没有AutoLayout的项目

#6

extension String{

extension String {

func height(withConstrainedWidth width: CGFloat, font: UIFont) -> CGFloat {

func height（withConstrainedWidth width：CGFloat，font：UIFont） - > CGFloat {

    let constraintRect = CGSize(width: width, height: .greatestFiniteMagnitude)

    let boundingBox = self.boundingRect(with: constraintRect, options: .usesLineFragmentOrigin, attributes: [NSFontAttributeName: font], context: nil)
    return ceil(boundingBox.height)
}}

#7

Crate an String extension

Crate一个String扩展

extension String {
    func heightOfString(usingFont font: UIFont) -> CGFloat {
        let fontAttributes = [NSFontAttributeName: font]
        let size = self.size(attributes: fontAttributes)
        return size.height
    }
}

get the height of the string as follows

获取字符串的高度如下

let str = "Hello world"
let strHgt = str.heightOfString(usingFont: UIFont.systemFont(ofSize: 12))

#1