如何在动态导航栏中调整标题大小

Question

我有一些视图显示在导航控制器中。其中两个视图对导航栏的标题较长。

问题是，当标题太长以至于不适合时，某些字符会被截断并添加“...”。

有什么办法可以告诉导航栏自动重新调整标题文本的大小以适应？

Answer 1

用于viewDidLoad中下面的代码。

目标C

self.title = @"Your TiTle Text"; 
UILabel* tlabel=[[UILabel alloc] initWithFrame:CGRectMake(0,0, 200, 40)]; 
tlabel.text=self.navigationItem.title; 
tlabel.textColor=[UIColor whiteColor]; 
tlabel.font = [UIFont fontWithName:@"Helvetica-Bold" size: 30.0]; 
tlabel.backgroundColor =[UIColor clearColor]; 
tlabel.adjustsFontSizeToFitWidth=YES; 
tlabel.textAlignment = NSTextAlignmentCenter; 
self.navigationItem.titleView=tlabel; 

斯威夫特版本

self.title = "Your TiTle Text" 
let tlabel = UILabel(frame: CGRectMake(0, 0, 200, 40)) 
tlabel.text = self.title 
tlabel.textColor = UIColor.whiteColor() 
tlabel.font = UIFont(name: "Helvetica-Bold", size: 30.0) 
tlabel.backgroundColor = UIColor.clearColor() 
tlabel.adjustsFontSizeToFitWidth = true 
tlabel.textAlignment = .center; 
self.navigationItem.titleView = tlabel 

希望工程为周到，谢谢

Answer 2

你需要定制具有的UILabel导航栏标题视图，并提供调整字体大小..

[self.navigationItem setTitleView:<"Include any UI View subclass">]; 

Answer 3

下面是斯威夫特的例子还允许多条线路。使用PureLayout可简化自动布局。

override func viewDidLoad() { 
    super.viewDidLoad() 
    configureTitleView() 
} 

func configureTitleView() { 
    let titleLabel = UILabel() 
    titleLabel.numberOfLines = 0 
    titleLabel.textAlignment = .Center 
    titleLabel.font = UIFont.boldSystemFontOfSize(17.0) 
    titleLabel.text = searchLoc.mapItem.name 
    navigationItem.titleView = titleLabel 
    titleLabel.autoPinEdgesToSuperviewMargins() // PureLayout method 
    titleLabel.adjustsFontSizeToFitWidth = true 
} 

以及使用例如：

Answer 4

上述解决方案缝都不可靠地为我工作。 但是我发现了一个解决方案，它使用Swift 2中的不同元素提供答案，并且它非常优雅，因为每次更改标签时都不需要任何自定义代码，它只是在标题上使用属性观察器。

请注意，在我的情况下，我在导航栏的左侧有一个后退按钮，将文本置于屏幕中央，以解决此问题，我正在使用属性文本和tailIndent。所有评论在下面的代码/信息：

class VCHowToTopic : UIViewController { 


    //add handlers so that any manipulation of the title is caught and transferred to the custom drawn UILabel 
    override var title : String? { 
     set { 
      super.title = newValue 
      configureTitleView() 
     } 
     get { 
      return super.title 
     } 
    } 

    //MARK: - lifecycle 


    func configureTitleView() { 
     //some large number that makes the navigationbar schrink down our view when added 
     let someVeryLargeNumber = CGFloat(4096) 
     //create our label 
     let titleLabel = UILabel(frame: CGRect(x: 0, y: 0, width: someVeryLargeNumber, height: someVeryLargeNumber)) 
     //0 means unlimited number of lines 
     titleLabel.numberOfLines = 0 
     //define style of the text (we will be using attributed text) 
     let style = NSMutableParagraphStyle() 
     style.alignment = .Center 
     //top compensate for the backbutton which moves the centered text to the right side of the screen 
     //we introduce a negative tail indent, the number of 56 has been experimentally defined and might 
     //depend on the size of your custom back button (if you have one), mine is 22x22 px 
     style.tailIndent = -56 
     //create attributed text also with the right color 
     let attrText = NSAttributedString(string: title!, attributes: [NSParagraphStyleAttributeName : style, 
      NSForegroundColorAttributeName : UIColor.whiteColor()]) 
     //configure the label to use the attributed text 
     titleLabel.attributedText = attrText 
     //add it as the titleview 
     navigationItem.titleView = titleLabel 
    } 


} 

Answer 5

接受的斯威夫特版本答案+把标签文本的中心：

雨燕2.3：

self.title = "Your TiTle Text" 
    let tlabel = UILabel(frame: CGRectMake(0, 0, 200, 40)) 
    tlabel.text = self.title 
    tlabel.textColor = UIColor.whiteColor() 
    tlabel.font = UIFont.boldSystemFontOfSize(17) //UIFont(name: "Helvetica", size: 17.0) 
    tlabel.backgroundColor = UIColor.clearColor() 
    tlabel.adjustsFontSizeToFitWidth = true 
    tlabel.textAlignment = .Center 
    self.navigationItem.titleView = tlabel 

和SWIFT 3：

self.title = "Your TiTle Text" 
    let frame = CGRect(x: 0, y: 0, width: 200, height: 40) 
    let tlabel = UILabel(frame: frame) 
    tlabel.text = self.title 
    tlabel.textColor = UIColor.white 
    tlabel.font = UIFont.boldSystemFont(ofSize: 17) //UIFont(name: "Helvetica", size: 17.0) 
    tlabel.backgroundColor = UIColor.clear 
    tlabel.adjustsFontSizeToFitWidth = true 
    tlabel.textAlignment = .center 
    self.navigationItem.titleView = tlabel 

Answer 6

如果你有一个视图添加到titleView中，并且你想调整视图的大小，你可以使用这个代码（SWIFT 3）：

self.translatesAutoresizingMaskIntoConstraints = false 
self.layoutIfNeeded() 
self.sizeToFit() 
self.translatesAutoresizingMaskIntoConstraints = true