自动调整表格视图单元格中 UILabel 中的行数
Number of lines in UILabel in self-sizing tableview cell
编辑 2-我能够通过使用在不同问题 () 中找到的不同方法使其工作，但我也将它与GeneratorOfOne 提供的代码，我已经在下面发布了我的结果。不过，我仍然 运行 对此的最终目标感兴趣。目标是在每行文本旁边添加行号，有点像在代码编辑器中。问题是我需要保留 运行ning 行数，所以如果第一个单元格中有 3 行，第二个单元格中的行号应该从 4 开始，依此类推，但我没有相信我可以这样做，因为正在计算单元格中的行数，所以我不能 return 将值返回到 tableview 以设置第二个标签的文本（行号）...有什么想法吗？
override func layoutSubviews() {
super.layoutSubviews()
calculateNumberOfLines()
}
var textDetail: String? {
didSet {
gameInfo.text = textDetail
}
}
func calculateNumberOfLines() {
let layoutManager = NSLayoutManager()
let textStorage = NSTextStorage(string: self.gameInfo!.text!)
textStorage.addAttribute(NSFontAttributeName, value: self.gameInfo!.font, range: NSMakeRange(0, textStorage.length))
let textContainer = NSTextContainer(size: CGSize(width:self.contentView.bounds.size.width - 56.0, height: CGFloat.max))
layoutManager.addTextContainer(textContainer)
layoutManager.textStorage = textStorage
if let text = gameInfo?.text {
let numberOfLines = getLinesArrayOfStringInLabel(gameInfo)
lineNumbers.text = "\(startingNum)"
for index in startingNum+1...startingNum+numberOfLines {
lineNumbers.text = lineNumbers.text?.stringByAppendingString("\n\(index)")
}
endingNum = startingNum+numberOfLines
//let numberOfLines = totalNumberOfLinesIn(text, currentGlyphIndex:0, currentLineNumber: 1, layoutManager: layoutManager, textContainer: textContainer)
//lineNumbers.text = "\(numberOfLines)"
} else { return }
}
func getLinesArrayOfStringInLabel(label: UILabel) -> Int {
var text = label.text as! NSString
var font = label.font
var rect = label.frame
var myFont = CTFontCreateWithName(font.fontName, font.pointSize, nil)
var attrString = NSMutableAttributedString(string: text as String)
attrString.addAttribute(String(kCTFontAttributeName), value: myFont, range: NSMakeRange(0, attrString.length))
let frameSetter = CTFramesetterCreateWithAttributedString(attrString)
var path = CGPathCreateMutable()
CGPathAddRect(path, nil, CGRectMake(0,0,rect.size.width,100000))
var frame = CTFramesetterCreateFrame(frameSetter, CFRangeMake(0, 0), path, nil)
var lines = CTFrameGetLines(frame) as NSArray
var linesArray = NSMutableArray()
for line in lines as [AnyObject] {
var lineRef = line as! CTLineRef
var lineRange = CTLineGetStringRange(lineRef)
var range = NSMakeRange(lineRange.location, lineRange.length)
var lineString = text.substringWithRange(range)
linesArray.addObject(lineString)
}
return linesArray.count
}
我有一个使用自动调整单元格的自定义 UITableViewCell 子类。细胞的大小是完美的，标签被正确地延伸。但是，在 运行 时，我试图计算标签将扩展到的行数（我需要在标签旁边显示行号），但我无法实现这一点。我已经尝试了以下两种方法，但似乎都没有 returning 我在应用 运行s:
时看到的正确行数
func lineCountForText(string: String, label: UILabel) -> Int {
let font: UIFont = UIFont(name: "SourceCodePro-Regular", size: label.font.pointSize)!
let rect = string.boundingRectWithSize(CGSizeMake(label.frame.width, CGFloat(MAXFLOAT)), options: NSStringDrawingOptions.UsesLineFragmentOrigin, attributes: [font : NSFontAttributeName], context: nil)
return Int(ceil(rect.size.height/font.lineHeight))
}
func numberOfLinesForString(string: String, size: CGSize, font: UIFont) -> Int {
let textStorage = NSTextStorage(string: string, attributes: [NSFontAttributeName: font])
let textContainer = NSTextContainer(size: size)
textContainer.lineBreakMode = .ByWordWrapping
textContainer.maximumNumberOfLines = 0
textContainer.lineFragmentPadding = 0
let layoutManager = NSLayoutManager()
layoutManager.textStorage = textStorage
layoutManager.addTextContainer(textContainer)
var numberOfLines = 0
var index = 0
var lineRange : NSRange = NSMakeRange(0, 0)
for (; index < layoutManager.numberOfGlyphs; numberOfLines++) {
layoutManager.lineFragmentRectForGlyphAtIndex(index, effectiveRange: &lineRange)
index = NSMaxRange(lineRange)
}
return numberOfLines
}
我不能这样做是因为它是一个自动调整大小的单元格吗？
编辑 - 这是我正在使用的文本数组：
var randomSizedTexts = [
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.\nUt enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.",
"Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt explicabo. ullam corporis suscipit laboriosam, nisi ut aliquid ex ea commodi consequatur?",
"Nemo enim ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit incidunt ut labore et dolore magnam aliquam quaerat voluptatem. Ut enim ad minima veniam, quis nostrum exercitationem",
", sed quia consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt. Neque porro quisquam est, qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit, sed quia non numquam eius modi tempora",
"At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident",
"Et harum quidem rerum facilis est et expedita distinctio",
"Mauris id efficitur sapien. Nunc lobortis nisi ut ultricies scelerisque. Curabitur accumsan sit amet lacus in finibus. Aliquam dolor ante, rhoncus sit amet fermentum et, semper sit amet nisi. Proin pretium velit ut quam mollis fringilla. Nullam neque risus, vestibulum eget tortor sit amet, suscipit ultricies metus. In tortor ipsum, feugiat lacinia leo id, pulvinar lacinia velit. Suspendisse sit amet porta tellus, et scelerisque odio. Nam convallis sodales congue. Proin vel quam id arcu nisi non.",
]
为所有单元格实现动态高度。
这是一个例子。在这个例子中，单元格有一个标签。
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
cellHeight = 40.0f; // Height excluding label height
// Calculate label height
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 288, 0)];
label.font = [UIFont systemFontOfSize:13];
label.text = [details objectAtIndex:indexPath.row];
label.numberOfLines = 0;
[label sizeToFit];
cellHeight += [PSIUtility heightForLabel:label];
label.text = [tips objectAtIndex:indexPath.row];
label.numberOfLines = 0;
[label sizeToFit];
cellHeight += [self heightForLabel:label];
//Return cell Height
return cellHeight;
}
- (CGFloat)heightForLabel:(UILabel *)label{
//Calculate the expected size based on the font and linebreak mode of your label
// FLT_MAX here simply means no constraint in height
label.numberOfLines = 0;
CGSize maximumLabelSize = CGSizeMake(label.frame.size.width, FLT_MAX);
// CGSize expectedLabelSize = [label.text sizeWithFont:label.font constrainedToSize:maximumLabelSize lineBreakMode:label.lineBreakMode];
CGRect expectedLabelSize = [label.text boundingRectWithSize:maximumLabelSize
options:(NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading)
attributes:@{NSFontAttributeName:label.font}
context:nil];
return expectedLabelSize.size.height;
}
您可以使用 labelHeight/12.0f 表示行数，其中 12.0f 是所使用的字体大小。
正在尝试使用 NSAttributedString:
func lineCountForLabel(label: UILabel) -> Int {
let font: UIFont = label.font
let attribtedString = label.attributedText.mutableCopy() as! NSMutableAttributedString
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineBreakMode = label.lineBreakMode
attribtedString.addAttribute(NSParagraphStyleAttributeName, value: paragraphStyle, range: NSRange(location: 0, length: attribtedString.length))
let rect = attribtedString.boundingRectWithSize(CGSizeMake(label.frame.width, CGFloat(MAXFLOAT)),
options: .UsesLineFragmentOrigin | .UsesFontLeading,
context: nil)
return Int(ceil(rect.size.height/font.lineHeight))
}
更新：
你可以把shorthand形式的字典类型写成[Key:Value]，所以你的这一行是不正确的：
let rect = string.boundingRectWithSize(xx, xx, xx, attributes: [font : NSFontAttributeName], context: nil)
变化：
[font : NSFontAttributeName]
至：
[NSFontAttributeName : font]
UPDATE（问题更新后）
您应该像这样在数据源中存储行号：
class MyCell: UITableViewCell {
@IBOutlet var contentLabel: UILabel!
@IBOutlet private var numberLabel: UILabel!
}
class MasterViewController: UITableViewController {
var objects = [AnyObject]()
override func viewDidLoad() {
super.viewDidLoad()
let addButton = UIBarButtonItem(barButtonSystemItem: .Add, target: self, action: "insertNewObject:")
self.navigationItem.rightBarButtonItem = addButton
self.tableView.estimatedRowHeight = 44
self.tableView.rowHeight = UITableViewAutomaticDimension
self.insertNewObject(self)
self.insertNewObject(self)
self.insertNewObject(self)
self.insertNewObject(self)
self.insertNewObject(self)
self.insertNewObject(self)
self.insertNewObject(self)
self.insertNewObject(self)
self.insertNewObject(self)
self.insertNewObject(self)
}
func insertNewObject(sender: AnyObject) {
var count = Int(arc4random_uniform(20)) + 1
var string = ""
while (count-- > 0) {
string += "This is a test."
}
objects.insert(["content" : string, "lineNumber" : 0], atIndex: 0)
}
// MARK: - Table View
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return objects.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! MyCell
var object = objects[indexPath.row] as! [String : AnyObject]
var startLineNumber = 0
if indexPath.row > 0 {
var pObject = objects[indexPath.row - 1] as! [String : AnyObject]
startLineNumber = pObject["lineNumber"] as! Int
}
cell.contentView.setNeedsLayout()
cell.contentView.layoutIfNeeded()
cell.contentLabel.text = object["content"] as? String
let lineNumber = lineCountForLabel(cell.contentLabel) + startLineNumber
cell.numberLabel.text = "\(lineNumber)"
object["lineNumber"] = lineNumber
objects[indexPath.row] = object
return cell
}
func lineCountForLabel(label: UILabel) -> Int {
let font: UIFont = label.font
let attribtedString = label.attributedText.mutableCopy() as! NSMutableAttributedString
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineBreakMode = label.lineBreakMode
attribtedString.addAttribute(NSParagraphStyleAttributeName, value: paragraphStyle, range: NSRange(location: 0, length: attribtedString.length))
let rect = attribtedString.boundingRectWithSize(CGSizeMake(label.frame.width, CGFloat(MAXFLOAT)),
options: .UsesLineFragmentOrigin | .UsesFontLeading,
context: nil)
return Int(ceil(rect.size.height/font.lineHeight))
}
}
更新:
您的演示中存在一些问题。
改变
lastNumUsed = 1
到
lastNumUsed = 0
并改变
for index in lastNumUsed+1...lastNumUsed+numLines
到
for index in lastNumUsed+1...lastNumUsed+numLines-1
最后，问题的关键在于gameInfo的尺寸是否正确。当 cellForRow 执行它的超级视图时可能为 nil，因此单元格的大小和 gameInfo 不正确。相反，您应该像这样计算 willDisplayCell 中的行数：
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell: LineNumberSubtitleCell! = tableView.dequeueReusableCellWithIdentifier("GameCell", forIndexPath: indexPath) as! LineNumberSubtitleCell
if cell == nil {
cell = LineNumberSubtitleCell(style: UITableViewCellStyle.Default, reuseIdentifier: "GameCell")
}
cell.gameInfo.text = randomSizedTexts[indexPath.row]
return cell
}
override func tableView(tableView: UITableView, willDisplayCell cell: UITableViewCell, forRowAtIndexPath indexPath: NSIndexPath) {
let cell = cell as! LineNumberSubtitleCell
cell.contentView.setNeedsLayout()
cell.contentView.layoutIfNeeded()
let numLines = getLinesArrayOfStringInLabel(cell.gameInfo)
cell.lineNumbers.text = "\(lastNumUsed)"
if !(lineNumbersList.count > indexPath.row) {
for index in lastNumUsed+1...lastNumUsed+numLines-1 {
cell.lineNumbers.text = cell.lineNumbers.text?.stringByAppendingString("\n\(index)")
if index == lastNumUsed+numLines-1 {
lastNumUsed = index+1
lineNumbersList.addObject(cell.lineNumbers.text!)
}
}
} else {
cell.lineNumbers.text = lineNumbersList.objectAtIndex(indexPath.row) as? String
}
}
调用 setNeedsLayout 方法会强制您的视图更新其布局。现在调用 layoutIfNeeded 方法强制布局系统为 运行。因此 gameInfo 的大小应该重新计算以更正。
这是一个计算文本行数的简单示例。
该方法递归地查找字形索引，并获取一个线段并比较索引处的字形是否为最后一个。
class TableViewCell: UITableViewCell {
var index: Int = 0
var titleLabel: UILabel!
var numberOfLinesLabel: UILabel!
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
titleLabel = UILabel(frame: CGRectZero)
titleLabel.translatesAutoresizingMaskIntoConstraints = false
titleLabel.numberOfLines = 0
titleLabel.lineBreakMode = NSLineBreakMode.ByWordWrapping
contentView.addSubview(titleLabel)
numberOfLinesLabel = UILabel(frame: CGRectZero)
numberOfLinesLabel.translatesAutoresizingMaskIntoConstraints = false
contentView.addSubview(numberOfLinesLabel)
contentView.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|-10-[titleLabel]-10-|", options: NSLayoutFormatOptions(rawValue: 0), metrics: nil, views: ["titleLabel": titleLabel]))
contentView.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|-20-[titleLabel]-[numberOfLinesLabel(==28)]|", options: NSLayoutFormatOptions.AlignAllTop, metrics: nil, views: ["titleLabel": titleLabel, "numberOfLinesLabel": numberOfLinesLabel]))
}
required init(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
var textDetail: String? {
didSet {
titleLabel.text = textDetail
}
}
override func layoutSubviews() {
super.layoutSubviews()
calculateNumberOfLines()
}
func calculateNumberOfLines() {
let layoutManager = NSLayoutManager()
let textStorage = NSTextStorage(string: self.titleLabel!.text!)
textStorage.addAttribute(NSFontAttributeName, value: self.titleLabel!.font, range: NSMakeRange(0, textStorage.length))
let textContainer = NSTextContainer(size: self.titleLabel!.bounds.size)
layoutManager.addTextContainer(textContainer)
layoutManager.textStorage = textStorage
guard let text = titleLabel?.text else { return }
let numberOfLines = totalNumberOfLinesIn(text: text, currentGlyphIndex:0, currentLineNumber: 1, layoutManager: layoutManager, textContainer: textContainer)
numberOfLinesLabel.text = "\(numberOfLines)"
}
func totalNumberOfLinesIn(text text: String, currentGlyphIndex glyphIndex:Int, currentLineNumber line:Int, layoutManager: NSLayoutManager, textContainer: NSTextContainer) -> Int
{
let maxGlyphIndex = layoutManager.glyphRangeForTextContainer(textContainer)
let lineFragment = layoutManager.lineFragmentRectForGlyphAtIndex(glyphIndex, effectiveRange: nil)
let glyphRange = layoutManager.glyphRangeForBoundingRect(lineFragment, inTextContainer: textContainer)
if NSMaxRange(glyphRange) < NSMaxRange(maxGlyphIndex) {
return totalNumberOfLinesIn(text: text, currentGlyphIndex:glyphIndex + glyphRange.length, currentLineNumber: (line + 1), layoutManager: layoutManager, textContainer: textContainer)
}
return line
}
}
class TestViewController: UIViewController{
static let CellIdentifier = "CellIdentifier"
var randomSizedTexts = [
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.\nUt enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.",
"Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt explicabo. ullam corporis suscipit laboriosam, nisi ut aliquid ex ea commodi consequatur?",
"Nemo enim ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit incidunt ut labore et dolore magnam aliquam quaerat voluptatem. Ut enim ad minima veniam, quis nostrum exercitationem",
", sed quia consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt. Neque porro quisquam est, qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit, sed quia non numquam eius modi tempora",
"At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident",
"Et harum quidem rerum facilis est et expedita distinctio",
"Mauris id efficitur sapien. Nunc lobortis nisi ut ultricies scelerisque. Curabitur accumsan sit amet lacus in finibus. Aliquam dolor ante, rhoncus sit amet fermentum et, semper sit amet nisi. Proin pretium velit ut quam mollis fringilla. Nullam neque risus, vestibulum eget tortor sit amet, suscipit ultricies metus. In tortor ipsum, feugiat lacinia leo id, pulvinar lacinia velit. Suspendisse sit amet porta tellus, et scelerisque odio. Nam convallis sodales congue. Proin vel quam id arcu nisi non.",
]
lazy var tableView: UITableView! = {
let tableView = UITableView(frame: CGRectZero, style: .Plain)
tableView.translatesAutoresizingMaskIntoConstraints = false
tableView.delegate = self
tableView.dataSource = self
tableView.rowHeight = UITableViewAutomaticDimension
tableView.estimatedRowHeight = 44
self.view.addSubview(tableView)
self.view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|[tableView]|", options: NSLayoutFormatOptions(rawValue: 0), metrics: nil, views: ["tableView": tableView]))
self.view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|[tableView]|", options: NSLayoutFormatOptions(rawValue: 0), metrics: nil, views: ["tableView": tableView]))
return tableView
}()
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = UIColor.whiteColor()
tableView.registerClass(TableViewCell.self, forCellReuseIdentifier: TestViewController.CellIdentifier)
}
}
extension TestViewController: UITableViewDataSource, UITableViewDelegate {
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier(TestViewController.CellIdentifier, forIndexPath: indexPath) as! TableViewCell
cell.index = indexPath.row
cell.textDetail = randomSizedTexts[indexPath.row]
return cell
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return randomSizedTexts.count
}
}
更新：似乎根据 titleLabel 大小设置 NSTextContainer 大小不合适。由于此时 titleLabel 大小不太合适。似乎手动计算可用于显示标签的边界大小给出了正确的结果。请查看更改。
编辑 2-我能够通过使用在不同问题 () 中找到的不同方法使其工作，但我也将它与GeneratorOfOne 提供的代码，我已经在下面发布了我的结果。不过，我仍然 运行 对此的最终目标感兴趣。目标是在每行文本旁边添加行号，有点像在代码编辑器中。问题是我需要保留 运行ning 行数，所以如果第一个单元格中有 3 行，第二个单元格中的行号应该从 4 开始，依此类推，但我没有相信我可以这样做，因为正在计算单元格中的行数，所以我不能 return 将值返回到 tableview 以设置第二个标签的文本（行号）...有什么想法吗？
override func layoutSubviews() {
super.layoutSubviews()
calculateNumberOfLines()
}
var textDetail: String? {
didSet {
gameInfo.text = textDetail
}
}
func calculateNumberOfLines() {
let layoutManager = NSLayoutManager()
let textStorage = NSTextStorage(string: self.gameInfo!.text!)
textStorage.addAttribute(NSFontAttributeName, value: self.gameInfo!.font, range: NSMakeRange(0, textStorage.length))
let textContainer = NSTextContainer(size: CGSize(width:self.contentView.bounds.size.width - 56.0, height: CGFloat.max))
layoutManager.addTextContainer(textContainer)
layoutManager.textStorage = textStorage
if let text = gameInfo?.text {
let numberOfLines = getLinesArrayOfStringInLabel(gameInfo)
lineNumbers.text = "\(startingNum)"
for index in startingNum+1...startingNum+numberOfLines {
lineNumbers.text = lineNumbers.text?.stringByAppendingString("\n\(index)")
}
endingNum = startingNum+numberOfLines
//let numberOfLines = totalNumberOfLinesIn(text, currentGlyphIndex:0, currentLineNumber: 1, layoutManager: layoutManager, textContainer: textContainer)
//lineNumbers.text = "\(numberOfLines)"
} else { return }
}
func getLinesArrayOfStringInLabel(label: UILabel) -> Int {
var text = label.text as! NSString
var font = label.font
var rect = label.frame
var myFont = CTFontCreateWithName(font.fontName, font.pointSize, nil)
var attrString = NSMutableAttributedString(string: text as String)
attrString.addAttribute(String(kCTFontAttributeName), value: myFont, range: NSMakeRange(0, attrString.length))
let frameSetter = CTFramesetterCreateWithAttributedString(attrString)
var path = CGPathCreateMutable()
CGPathAddRect(path, nil, CGRectMake(0,0,rect.size.width,100000))
var frame = CTFramesetterCreateFrame(frameSetter, CFRangeMake(0, 0), path, nil)
var lines = CTFrameGetLines(frame) as NSArray
var linesArray = NSMutableArray()
for line in lines as [AnyObject] {
var lineRef = line as! CTLineRef
var lineRange = CTLineGetStringRange(lineRef)
var range = NSMakeRange(lineRange.location, lineRange.length)
var lineString = text.substringWithRange(range)
linesArray.addObject(lineString)
}
return linesArray.count
}
我有一个使用自动调整单元格的自定义 UITableViewCell 子类。细胞的大小是完美的，标签被正确地延伸。但是，在 运行 时，我试图计算标签将扩展到的行数（我需要在标签旁边显示行号），但我无法实现这一点。我已经尝试了以下两种方法，但似乎都没有 returning 我在应用 运行s:
时看到的正确行数func lineCountForText(string: String, label: UILabel) -> Int {
let font: UIFont = UIFont(name: "SourceCodePro-Regular", size: label.font.pointSize)!
let rect = string.boundingRectWithSize(CGSizeMake(label.frame.width, CGFloat(MAXFLOAT)), options: NSStringDrawingOptions.UsesLineFragmentOrigin, attributes: [font : NSFontAttributeName], context: nil)
return Int(ceil(rect.size.height/font.lineHeight))
}
func numberOfLinesForString(string: String, size: CGSize, font: UIFont) -> Int {
let textStorage = NSTextStorage(string: string, attributes: [NSFontAttributeName: font])
let textContainer = NSTextContainer(size: size)
textContainer.lineBreakMode = .ByWordWrapping
textContainer.maximumNumberOfLines = 0
textContainer.lineFragmentPadding = 0
let layoutManager = NSLayoutManager()
layoutManager.textStorage = textStorage
layoutManager.addTextContainer(textContainer)
var numberOfLines = 0
var index = 0
var lineRange : NSRange = NSMakeRange(0, 0)
for (; index < layoutManager.numberOfGlyphs; numberOfLines++) {
layoutManager.lineFragmentRectForGlyphAtIndex(index, effectiveRange: &lineRange)
index = NSMaxRange(lineRange)
}
return numberOfLines
}
我不能这样做是因为它是一个自动调整大小的单元格吗？
编辑 - 这是我正在使用的文本数组：
var randomSizedTexts = [
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.\nUt enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.",
"Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt explicabo. ullam corporis suscipit laboriosam, nisi ut aliquid ex ea commodi consequatur?",
"Nemo enim ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit incidunt ut labore et dolore magnam aliquam quaerat voluptatem. Ut enim ad minima veniam, quis nostrum exercitationem",
", sed quia consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt. Neque porro quisquam est, qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit, sed quia non numquam eius modi tempora",
"At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident",
"Et harum quidem rerum facilis est et expedita distinctio",
"Mauris id efficitur sapien. Nunc lobortis nisi ut ultricies scelerisque. Curabitur accumsan sit amet lacus in finibus. Aliquam dolor ante, rhoncus sit amet fermentum et, semper sit amet nisi. Proin pretium velit ut quam mollis fringilla. Nullam neque risus, vestibulum eget tortor sit amet, suscipit ultricies metus. In tortor ipsum, feugiat lacinia leo id, pulvinar lacinia velit. Suspendisse sit amet porta tellus, et scelerisque odio. Nam convallis sodales congue. Proin vel quam id arcu nisi non.",
]
为所有单元格实现动态高度。 这是一个例子。在这个例子中，单元格有一个标签。
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
cellHeight = 40.0f; // Height excluding label height
// Calculate label height
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 288, 0)];
label.font = [UIFont systemFontOfSize:13];
label.text = [details objectAtIndex:indexPath.row];
label.numberOfLines = 0;
[label sizeToFit];
cellHeight += [PSIUtility heightForLabel:label];
label.text = [tips objectAtIndex:indexPath.row];
label.numberOfLines = 0;
[label sizeToFit];
cellHeight += [self heightForLabel:label];
//Return cell Height
return cellHeight;
}
- (CGFloat)heightForLabel:(UILabel *)label{
//Calculate the expected size based on the font and linebreak mode of your label
// FLT_MAX here simply means no constraint in height
label.numberOfLines = 0;
CGSize maximumLabelSize = CGSizeMake(label.frame.size.width, FLT_MAX);
// CGSize expectedLabelSize = [label.text sizeWithFont:label.font constrainedToSize:maximumLabelSize lineBreakMode:label.lineBreakMode];
CGRect expectedLabelSize = [label.text boundingRectWithSize:maximumLabelSize
options:(NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading)
attributes:@{NSFontAttributeName:label.font}
context:nil];
return expectedLabelSize.size.height;
}
您可以使用 labelHeight/12.0f 表示行数，其中 12.0f 是所使用的字体大小。
正在尝试使用 NSAttributedString:
func lineCountForLabel(label: UILabel) -> Int {
let font: UIFont = label.font
let attribtedString = label.attributedText.mutableCopy() as! NSMutableAttributedString
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineBreakMode = label.lineBreakMode
attribtedString.addAttribute(NSParagraphStyleAttributeName, value: paragraphStyle, range: NSRange(location: 0, length: attribtedString.length))
let rect = attribtedString.boundingRectWithSize(CGSizeMake(label.frame.width, CGFloat(MAXFLOAT)),
options: .UsesLineFragmentOrigin | .UsesFontLeading,
context: nil)
return Int(ceil(rect.size.height/font.lineHeight))
}
更新：
你可以把shorthand形式的字典类型写成[Key:Value]，所以你的这一行是不正确的：
let rect = string.boundingRectWithSize(xx, xx, xx, attributes: [font : NSFontAttributeName], context: nil)
变化：
[font : NSFontAttributeName]
至：
[NSFontAttributeName : font]
UPDATE（问题更新后）
您应该像这样在数据源中存储行号：
class MyCell: UITableViewCell {
@IBOutlet var contentLabel: UILabel!
@IBOutlet private var numberLabel: UILabel!
}
class MasterViewController: UITableViewController {
var objects = [AnyObject]()
override func viewDidLoad() {
super.viewDidLoad()
let addButton = UIBarButtonItem(barButtonSystemItem: .Add, target: self, action: "insertNewObject:")
self.navigationItem.rightBarButtonItem = addButton
self.tableView.estimatedRowHeight = 44
self.tableView.rowHeight = UITableViewAutomaticDimension
self.insertNewObject(self)
self.insertNewObject(self)
self.insertNewObject(self)
self.insertNewObject(self)
self.insertNewObject(self)
self.insertNewObject(self)
self.insertNewObject(self)
self.insertNewObject(self)
self.insertNewObject(self)
self.insertNewObject(self)
}
func insertNewObject(sender: AnyObject) {
var count = Int(arc4random_uniform(20)) + 1
var string = ""
while (count-- > 0) {
string += "This is a test."
}
objects.insert(["content" : string, "lineNumber" : 0], atIndex: 0)
}
// MARK: - Table View
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return objects.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! MyCell
var object = objects[indexPath.row] as! [String : AnyObject]
var startLineNumber = 0
if indexPath.row > 0 {
var pObject = objects[indexPath.row - 1] as! [String : AnyObject]
startLineNumber = pObject["lineNumber"] as! Int
}
cell.contentView.setNeedsLayout()
cell.contentView.layoutIfNeeded()
cell.contentLabel.text = object["content"] as? String
let lineNumber = lineCountForLabel(cell.contentLabel) + startLineNumber
cell.numberLabel.text = "\(lineNumber)"
object["lineNumber"] = lineNumber
objects[indexPath.row] = object
return cell
}
func lineCountForLabel(label: UILabel) -> Int {
let font: UIFont = label.font
let attribtedString = label.attributedText.mutableCopy() as! NSMutableAttributedString
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineBreakMode = label.lineBreakMode
attribtedString.addAttribute(NSParagraphStyleAttributeName, value: paragraphStyle, range: NSRange(location: 0, length: attribtedString.length))
let rect = attribtedString.boundingRectWithSize(CGSizeMake(label.frame.width, CGFloat(MAXFLOAT)),
options: .UsesLineFragmentOrigin | .UsesFontLeading,
context: nil)
return Int(ceil(rect.size.height/font.lineHeight))
}
}
更新:
您的演示中存在一些问题。
改变
lastNumUsed = 1
到
lastNumUsed = 0
并改变
for index in lastNumUsed+1...lastNumUsed+numLines
到
for index in lastNumUsed+1...lastNumUsed+numLines-1
最后，问题的关键在于gameInfo的尺寸是否正确。当 cellForRow 执行它的超级视图时可能为 nil，因此单元格的大小和 gameInfo 不正确。相反，您应该像这样计算 willDisplayCell 中的行数：
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell: LineNumberSubtitleCell! = tableView.dequeueReusableCellWithIdentifier("GameCell", forIndexPath: indexPath) as! LineNumberSubtitleCell
if cell == nil {
cell = LineNumberSubtitleCell(style: UITableViewCellStyle.Default, reuseIdentifier: "GameCell")
}
cell.gameInfo.text = randomSizedTexts[indexPath.row]
return cell
}
override func tableView(tableView: UITableView, willDisplayCell cell: UITableViewCell, forRowAtIndexPath indexPath: NSIndexPath) {
let cell = cell as! LineNumberSubtitleCell
cell.contentView.setNeedsLayout()
cell.contentView.layoutIfNeeded()
let numLines = getLinesArrayOfStringInLabel(cell.gameInfo)
cell.lineNumbers.text = "\(lastNumUsed)"
if !(lineNumbersList.count > indexPath.row) {
for index in lastNumUsed+1...lastNumUsed+numLines-1 {
cell.lineNumbers.text = cell.lineNumbers.text?.stringByAppendingString("\n\(index)")
if index == lastNumUsed+numLines-1 {
lastNumUsed = index+1
lineNumbersList.addObject(cell.lineNumbers.text!)
}
}
} else {
cell.lineNumbers.text = lineNumbersList.objectAtIndex(indexPath.row) as? String
}
}
调用 setNeedsLayout 方法会强制您的视图更新其布局。现在调用 layoutIfNeeded 方法强制布局系统为 运行。因此 gameInfo 的大小应该重新计算以更正。
这是一个计算文本行数的简单示例。
该方法递归地查找字形索引，并获取一个线段并比较索引处的字形是否为最后一个。
class TableViewCell: UITableViewCell {
var index: Int = 0
var titleLabel: UILabel!
var numberOfLinesLabel: UILabel!
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
titleLabel = UILabel(frame: CGRectZero)
titleLabel.translatesAutoresizingMaskIntoConstraints = false
titleLabel.numberOfLines = 0
titleLabel.lineBreakMode = NSLineBreakMode.ByWordWrapping
contentView.addSubview(titleLabel)
numberOfLinesLabel = UILabel(frame: CGRectZero)
numberOfLinesLabel.translatesAutoresizingMaskIntoConstraints = false
contentView.addSubview(numberOfLinesLabel)
contentView.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|-10-[titleLabel]-10-|", options: NSLayoutFormatOptions(rawValue: 0), metrics: nil, views: ["titleLabel": titleLabel]))
contentView.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|-20-[titleLabel]-[numberOfLinesLabel(==28)]|", options: NSLayoutFormatOptions.AlignAllTop, metrics: nil, views: ["titleLabel": titleLabel, "numberOfLinesLabel": numberOfLinesLabel]))
}
required init(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
var textDetail: String? {
didSet {
titleLabel.text = textDetail
}
}
override func layoutSubviews() {
super.layoutSubviews()
calculateNumberOfLines()
}
func calculateNumberOfLines() {
let layoutManager = NSLayoutManager()
let textStorage = NSTextStorage(string: self.titleLabel!.text!)
textStorage.addAttribute(NSFontAttributeName, value: self.titleLabel!.font, range: NSMakeRange(0, textStorage.length))
let textContainer = NSTextContainer(size: self.titleLabel!.bounds.size)
layoutManager.addTextContainer(textContainer)
layoutManager.textStorage = textStorage
guard let text = titleLabel?.text else { return }
let numberOfLines = totalNumberOfLinesIn(text: text, currentGlyphIndex:0, currentLineNumber: 1, layoutManager: layoutManager, textContainer: textContainer)
numberOfLinesLabel.text = "\(numberOfLines)"
}
func totalNumberOfLinesIn(text text: String, currentGlyphIndex glyphIndex:Int, currentLineNumber line:Int, layoutManager: NSLayoutManager, textContainer: NSTextContainer) -> Int
{
let maxGlyphIndex = layoutManager.glyphRangeForTextContainer(textContainer)
let lineFragment = layoutManager.lineFragmentRectForGlyphAtIndex(glyphIndex, effectiveRange: nil)
let glyphRange = layoutManager.glyphRangeForBoundingRect(lineFragment, inTextContainer: textContainer)
if NSMaxRange(glyphRange) < NSMaxRange(maxGlyphIndex) {
return totalNumberOfLinesIn(text: text, currentGlyphIndex:glyphIndex + glyphRange.length, currentLineNumber: (line + 1), layoutManager: layoutManager, textContainer: textContainer)
}
return line
}
}
class TestViewController: UIViewController{
static let CellIdentifier = "CellIdentifier"
var randomSizedTexts = [
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.\nUt enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.",
"Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt explicabo. ullam corporis suscipit laboriosam, nisi ut aliquid ex ea commodi consequatur?",
"Nemo enim ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit incidunt ut labore et dolore magnam aliquam quaerat voluptatem. Ut enim ad minima veniam, quis nostrum exercitationem",
", sed quia consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt. Neque porro quisquam est, qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit, sed quia non numquam eius modi tempora",
"At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident",
"Et harum quidem rerum facilis est et expedita distinctio",
"Mauris id efficitur sapien. Nunc lobortis nisi ut ultricies scelerisque. Curabitur accumsan sit amet lacus in finibus. Aliquam dolor ante, rhoncus sit amet fermentum et, semper sit amet nisi. Proin pretium velit ut quam mollis fringilla. Nullam neque risus, vestibulum eget tortor sit amet, suscipit ultricies metus. In tortor ipsum, feugiat lacinia leo id, pulvinar lacinia velit. Suspendisse sit amet porta tellus, et scelerisque odio. Nam convallis sodales congue. Proin vel quam id arcu nisi non.",
]
lazy var tableView: UITableView! = {
let tableView = UITableView(frame: CGRectZero, style: .Plain)
tableView.translatesAutoresizingMaskIntoConstraints = false
tableView.delegate = self
tableView.dataSource = self
tableView.rowHeight = UITableViewAutomaticDimension
tableView.estimatedRowHeight = 44
self.view.addSubview(tableView)
self.view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|[tableView]|", options: NSLayoutFormatOptions(rawValue: 0), metrics: nil, views: ["tableView": tableView]))
self.view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|[tableView]|", options: NSLayoutFormatOptions(rawValue: 0), metrics: nil, views: ["tableView": tableView]))
return tableView
}()
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = UIColor.whiteColor()
tableView.registerClass(TableViewCell.self, forCellReuseIdentifier: TestViewController.CellIdentifier)
}
}
extension TestViewController: UITableViewDataSource, UITableViewDelegate {
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier(TestViewController.CellIdentifier, forIndexPath: indexPath) as! TableViewCell
cell.index = indexPath.row
cell.textDetail = randomSizedTexts[indexPath.row]
return cell
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return randomSizedTexts.count
}
}
更新：似乎根据 titleLabel 大小设置 NSTextContainer 大小不合适。由于此时 titleLabel 大小不太合适。似乎手动计算可用于显示标签的边界大小给出了正确的结果。请查看更改。