Swift - Playground - 核心图形/核心文本/自定义视图

Question

问题

我试图在Swift操场上制作一个自定义的UIView组件。我已经能够弄清楚除了正确呈现文本之外，如何做所有事情。我不确定我是否应该通过Core Graphics或Core Text来做到这一点，或者确切地说如何让它正常工作。

正如你可以在图片中看到下面我要呈现的文本都倒过来，正面朝上放在我的自定义视图部件的两侧

我已经试过各种方法来获得文字工作，但我一直搁浅。如果有人能够告诉我如何修改我的操场以添加一些很棒的文字渲染。

游乐场代码

// Playground - noun: a place where people can play 

import Foundation 
import UIKit 

class RunwayView : UIView { 


    var northText : String? 
    var southText : String? 


    ///Draws the "runway" 
    override func drawRect(rect: CGRect) { 

     // Setup graphics context 
     var ctx = UIGraphicsGetCurrentContext() 


     // clear context 
     CGContextClearRect(ctx, rect) 
     let parentVieBounds = self.bounds 
     let width = CGRectGetWidth(parentVieBounds) 
     let height = CGRectGetHeight(parentVieBounds) 


     // Setup the heights 
     let endZoneHeight : CGFloat = 40 


     /* Remember y is negative and 0,0 is upper left*/ 


     //Create EndZones 
     CGContextSetRGBFillColor(ctx, 0.8, 0.8, 0.8, 1) 
     CGContextFillRect(ctx, CGRectMake(0, 0, width, endZoneHeight)) 
     CGContextFillRect(ctx, CGRectMake(0, height-endZoneHeight, width, endZoneHeight)) 


     var northString = NSMutableAttributedString(string: "36") 
     var attrs = [NSFontAttributeName : UIFont.systemFontOfSize(16.0)] 
     var gString = NSMutableAttributedString(string:"g", attributes:attrs); 


     var line = CTLineCreateWithAttributedString(gString) 

     CGContextSetTextPosition(ctx, 10, 50); 
     CTLineDraw(line, ctx); 

     // Clean up 

    } 

} 


var outerFrame : UIView = UIView(frame: CGRectMake(20,20,400,400)) 
var runway1 : RunwayView = RunwayView(frame: CGRectMake(0,0,30,260)) 
var runway2 : RunwayView = RunwayView(frame: CGRectMake(80,0,30,340)) 

runway1.transform = CGAffineTransformConcat(CGAffineTransformMakeTranslation(20, 200), 
    CGAffineTransformMakeRotation(-0.785398163)) 
outerFrame.addSubview(runway1) 

runway2.transform = CGAffineTransformConcat(CGAffineTransformMakeTranslation(120, 140), 
    CGAffineTransformMakeRotation(-0.585398163)) 

outerFrame.addSubview(runway2) 



outerFrame.backgroundColor = UIColor.yellowColor() 
outerFrame.clipsToBounds = true 


// View these elements 
runway1 
outerFrame 
runway1 

Answer 1

我写了一个效用函数为我的应用程序中使用CoreText绘制文本。 它返回作进一步处理文字大小：

func drawText(context: CGContextRef, text: NSString, attributes: [String: AnyObject], x: CGFloat, y: CGFloat) -> CGSize { 
    let font = attributes[NSFontAttributeName] as UIFont 
    let attributedString = NSAttributedString(string: text, attributes: attributes) 

    let textSize = text.sizeWithAttributes(attributes) 

    // y: Add font.descender (its a negative value) to align the text at the baseline 
    let textPath = CGPathCreateWithRect(CGRect(x: x, y: y + font.descender, width: ceil(textSize.width), height: ceil(textSize.height)), nil) 
    let frameSetter = CTFramesetterCreateWithAttributedString(attributedString) 
    let frame  = CTFramesetterCreateFrame(frameSetter, CFRange(location: 0, length: attributedString.length), textPath, nil) 

    CTFrameDraw(frame, context) 

    return textSize 
} 

说它像这样：

var textAttributes: [String: AnyObject] = [ 
    NSForegroundColorAttributeName : UIColor(white: 1.0, alpha: 1.0).CGColor, 
    NSFontAttributeName : UIFont.systemFontOfSize(17) 
] 

drawText(ctx, text: "Hello, World!", attributes: textAttributes, x: 50, y: 50) 

希望帮助你。