Swift - Playground - 核心图形/核心文本/自定义视图 [英] Swift - Playground - Core Graphics / Core Text / Custom View

问题描述

我正在尝试在swift playground中创建自定义UIView组件。我已经能够弄清楚如何正确地执行除渲染文本之外的所有事情。我不确定我是否应该通过Core Graphics或Core Text执行此操作，或者确切地知道如何使其正常工作。

I'm attempting to make a custom UIView component in swift playground. I've been able to figure out how to do everything except for render text correctly. I'm not sure if i'm supposed to do this via Core Graphics or Core Text or exactly how to get it working correctly.

如下图所示，我想在自定义视图组件的两侧上下颠倒和右上方显示文本

As you can see in the image below I want to render text both upside down and right side up on either side of my custom View Component

我已经尝试了各种方法让文本工作但我一直搁浅。如果有人能够告诉我如何修改我的游乐场以添加一些令人敬畏的文字渲染。

I've tried various ways to get the text to work but I keep running aground. If somebody would be able to show me how to modify my playground to add a few text rendering that would be awesome.

// 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

推荐答案

我为我写了一个实用函数应用程序使用 CoreText 。
它返回文本大小以供进一步处理：

I wrote a utility function for my app to draw text using CoreText. It returns the text size for further processing:

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
}

这样称呼：

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)

希望对您有帮助。

这篇关于Swift - Playground - 核心图形/核心文本/自定义视图的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！