¿Es posible eliminar las imágenes en el UITabBarItem y alinear verticalmente el título

Question

Tengo un UITabBar pero no quiero configurar las imágenes Solo quiero configurar el título, y quiero que este título se alinee verticalmente. es posible?

Gracias

Answer 1

No es que yo sepa. Creo que necesitarías crear imágenes de tus etiquetas de texto (ya sea de antemano en tu herramienta gráfica preferida, o puedes crearlas programáticamente en tiempo de ejecución).

Si desea hacerlo mediante programación, un método como el siguiente podría hacerlo. Crea una imagen alineada al centro usando el texto que pasa, realizando un ajuste de palabras.

UITabBarItem *item = [self.tabBar.items objectAtIndex:0]; 
item.image = [self makeThumbnailFromText:@"Tab Bar One"]; 
item.title = nil; 

item = [self.tabBar.items objectAtIndex:1]; 
item.image = [self makeThumbnailFromText:@"Tab Bar Two"]; 
item.title = nil; 

Esto usa un pequeño método que crea un mapa de bits al procesar el texto que le pasa. Es posible que deba jugar con los tamaños de imagen y tamaños de fuente para optimizar las imágenes del controlador de la barra de pestañas.

- (UIImage *)makeThumbnailFromText:(NSString *)string { 
    // some variables that control the size of the image we create, what font to use, etc. 

    CGSize imageSize = CGSizeMake(60, 80); 
    CGFloat fontSize = 13.0; 
    NSString *fontName = @"Helvetica-Bold"; 
    UIFont *font = [UIFont fontWithName:fontName size:fontSize]; 
    CGFloat lineSpacing = fontSize * 1.2; 

    // set up the context and the font 

    UIGraphicsBeginImageContextWithOptions(imageSize, false, 0); 
    NSDictionary *attributes = @{NSFontAttributeName: font}; 

    // some variables we use for figuring out the words in the string and how to arrange them on lines of text 

    NSArray <NSString *> *words = [string componentsSeparatedByString:@" "]; 
    NSMutableArray <NSDictionary *> *lines = [NSMutableArray array]; 
    NSString *lineThusFar; 
    CGSize sizeThusFar = CGSizeZero; 

    // let's figure out the lines by examining the size of the rendered text and seeing whether it fits or not and 
    // figure out where we should break our lines (as well as using that to figure out how to center the text) 

    for (NSString *word in words) { 
     NSString *currentLine = lineThusFar ? [NSString stringWithFormat:@"%@ %@", lineThusFar, word] : word; 
     CGSize size = [currentLine sizeWithAttributes: attributes]; 
     if (size.width > imageSize.width && lineThusFar) { 
      [lines addObject:@{@"text": lineThusFar, @"size": [NSValue valueWithCGSize: sizeThusFar]}]; 
      lineThusFar = word; 
      sizeThusFar = [word sizeWithAttributes: attributes]; 
     } else { 
      lineThusFar = currentLine; 
      sizeThusFar = size; 
     } 
    } 
    if (lineThusFar) { 
     [lines addObject:@{@"text": lineThusFar, @"size": [NSValue valueWithCGSize: sizeThusFar]}]; 
    } 

    // now write the lines of text we figured out above 

    CGFloat totalSize = (lines.count - 1) * lineSpacing + fontSize; 
    CGFloat topMargin = (imageSize.height - totalSize)/2.0; 

    for (NSInteger i = 0; i < lines.count; i++) { 
     CGFloat x = (imageSize.width - [lines[i][@"size"] CGSizeValue].width)/2.0; 
     CGFloat y = topMargin + i * lineSpacing; 
     [lines[i][@"text"] drawAtPoint:CGPointMake(x, y) withAttributes: attributes]; 
    } 

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext(); 
    UIGraphicsEndImageContext(); 

    return image; 
} 

En Swift, que podría ser: solamente

func makeThumbnailFromText(text: String) -> UIImage { 
    // some variables that control the size of the image we create, what font to use, etc. 

    struct LineOfText { 
     var string: String 
     var size: CGSize 
    } 

    let imageSize = CGSize(width: 60, height: 80) 
    let fontSize: CGFloat = 13.0 
    let fontName = "Helvetica-Bold" 
    let font = UIFont(name: fontName, size: fontSize)! 
    let lineSpacing = fontSize * 1.2 

    // set up the context and the font 

    UIGraphicsBeginImageContextWithOptions(imageSize, false, 0) 
    let attributes = [NSFontAttributeName: font] 

    // some variables we use for figuring out the words in the string and how to arrange them on lines of text 

    let words = text.componentsSeparatedByString(" ") 
    var lines = [LineOfText]() 
    var lineThusFar: LineOfText? 

    // let's figure out the lines by examining the size of the rendered text and seeing whether it fits or not and 
    // figure out where we should break our lines (as well as using that to figure out how to center the text) 

    for word in words { 
     let currentLine = lineThusFar?.string == nil ? word : "\(lineThusFar!.string) \(word)" 
     let size = currentLine.sizeWithAttributes(attributes) 
     if size.width > imageSize.width && lineThusFar != nil { 
      lines.append(lineThusFar!) 
      lineThusFar = LineOfText(string: word, size: word.sizeWithAttributes(attributes)) 
     } else { 
      lineThusFar = LineOfText(string: currentLine, size: size) 
     } 
    } 
    if lineThusFar != nil { lines.append(lineThusFar!) } 

    // now write the lines of text we figured out above 

    let totalSize = CGFloat(lines.count - 1) * lineSpacing + fontSize 
    let topMargin = (imageSize.height - totalSize)/2.0 

    for (index, line) in lines.enumerate() { 
     let x = (imageSize.width - line.size.width)/2.0 
     let y = topMargin + CGFloat(index) * lineSpacing 
     line.string.drawAtPoint(CGPoint(x: x, y: y), withAttributes: attributes) 
    } 

    let image = UIGraphicsGetImageFromCurrentImageContext() 
    UIGraphicsEndImageContext() 

    return image 
} 

Y

var item = tabBar.items![0] 
item.image = makeThumbnailFromText("Tab Bar One") 
item.title = nil; 

item = tabBar.items![1] 
item.image = makeThumbnailFromText("Tab Bar Two") 
item.title = nil; 

Answer 2

para SWIFT

// mi artículo 3 es el centro de la imagen y los elementos de la barra de pestañas de descanso son solo texto

let tabs = CustomTabBarController(); 
tabs.viewControllers = [ViewControllerOne(),ViewControllerTwo(),ViewControllerThree()] 

    let tabbar = tabs.tabBar; 
    tabbar.backgroundColor = UIColor.white 

    let tabOne = tabbar.items![0] 
    tabOne.title = "One" 

    let tabTwo = tabbar.items![1] 
    tabTwo.imageInsets = UIEdgeInsetsMake(6, 0, -6, 0); 
    tabTwo.image = UIImage(named: "tab_icon.png") 

    let tabThree = tabbar.items![2] 
    tabThree.title = "Three" 

// y en mi CustomTabBarController

import UIKit 

class CustomTabBarController: UITabBarController { 

override func viewDidLoad() { 
    super.viewDidLoad() 

    UITabBar.appearance().tintColor = UIColor.black 
     UITabBarItem.appearance().titlePositionAdjustment = UIOffset(horizontal: 0, vertical: -15) 
} 

override func viewWillAppear(_ animated: Bool) { 
    super.viewWillAppear(true) 
    self.selectedIndex = 1; 
} 

override var selectedViewController: UIViewController? { 
    didSet { 

     guard let viewControllers = viewControllers else { 
      return 
     } 

     for viewController in viewControllers { 

      if viewController == selectedViewController { 

       let selected: [String: AnyObject] = 
        [NSFontAttributeName:fontForTimesRoman(withStyle: "bold", andFontsize: 12), 
        NSForegroundColorAttributeName: UIColor.black] 

       viewController.tabBarItem.setTitleTextAttributes(selected, for: .normal) 

      } else { 

       let normal: [String: AnyObject] = 
        [NSFontAttributeName: fontForTimesRoman(withStyle: "regular", andFontsize: 12), 
        NSForegroundColorAttributeName: UIColor.gray] 

       viewController.tabBarItem.setTitleTextAttributes(normal, for: .normal) 

       } 
      } 
     } 
    } 


    func fontForTimesRoman(withStyle style: String, andFontsize size: CGFloat) -> UIFont { 
if (style == "bold") { 
    return UIFont(name: "TimesNewRomanPS-BoldMT", size: size)! 
} 
else if(style == "italic"){ 
    return UIFont(name: "TimesNewRomanPS-ItalicMT", size: size)! 
} 
else{ 
    return UIFont(name: "TimesNewRomanPSMT", size: size)! 
    } 

    } 
    }