对于swift 3：

Question

我环顾四周并没有成功找出如何拍摄文字，将其叠加在图片上，然后将两者合并为一张UIImage。

我使用我能想到的搜索字词让Google筋疲力尽所以如果有人有解决方案或者至少提示他们可以指出它将会非常感激。

Answer 1

好的......我明白了：

func textToImage(drawText: NSString, inImage: UIImage, atPoint: CGPoint) -> UIImage{

    // Setup the font specific variables
    var textColor = UIColor.whiteColor()
    var textFont = UIFont(name: "Helvetica Bold", size: 12)!

    // Setup the image context using the passed image
    let scale = UIScreen.mainScreen().scale
    UIGraphicsBeginImageContextWithOptions(inImage.size, false, scale)

    // Setup the font attributes that will be later used to dictate how the text should be drawn
    let textFontAttributes = [
        NSFontAttributeName: textFont,
        NSForegroundColorAttributeName: textColor,
    ]

    // Put the image into a rectangle as large as the original image
    inImage.drawInRect(CGRectMake(0, 0, inImage.size.width, inImage.size.height))

    // Create a point within the space that is as bit as the image
    var rect = CGRectMake(atPoint.x, atPoint.y, inImage.size.width, inImage.size.height)

    // Draw the text into an image
    drawText.drawInRect(rect, withAttributes: textFontAttributes)

    // Create a new image out of the images we have created
    var newImage = UIGraphicsGetImageFromCurrentImageContext()

    // End the context now that we have the image we need
    UIGraphicsEndImageContext()

    //Pass the image back up to the caller
    return newImage

}

要调用它，您只需传入一张图片：

textToImage("000", inImage: UIImage(named:"thisImage.png")!, atPoint: CGPointMake(20, 20))

以下链接帮助我顺利完成：

Swift - Drawing text with drawInRect:withAttributes:

How to write text on image in Objective-C (iOS)?

最初的目标是创建一个我可以在AnnotaionView中使用的动态图像，例如在地图上的给定位置定价，这对它很有用。希望这有助于某些人尝试做同样的事情。

对于swift 3：

 func textToImage(drawText text: NSString, inImage image: UIImage, atPoint point: CGPoint) -> UIImage {
    let textColor = UIColor.white
    let textFont = UIFont(name: "Helvetica Bold", size: 12)!

    let scale = UIScreen.main.scale
    UIGraphicsBeginImageContextWithOptions(image.size, false, scale)

    let textFontAttributes = [
        NSFontAttributeName: textFont,
        NSForegroundColorAttributeName: textColor,
        ] as [String : Any]
    image.draw(in: CGRect(origin: CGPoint.zero, size: image.size))

    let rect = CGRect(origin: point, size: image.size)
    text.draw(in: rect, withAttributes: textFontAttributes)

    let newImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

    return newImage!
 }

对于swift 4：

 func textToImage(drawText text: String, inImage image: UIImage, atPoint point: CGPoint) -> UIImage {
    let textColor = UIColor.white
    let textFont = UIFont(name: "Helvetica Bold", size: 12)!

    let scale = UIScreen.main.scale
    UIGraphicsBeginImageContextWithOptions(image.size, false, scale)

    let textFontAttributes = [
        NSAttributedStringKey.font: textFont,
        NSAttributedStringKey.foregroundColor: textColor,
        ] as [NSAttributedStringKey : Any]
    image.draw(in: CGRect(origin: CGPoint.zero, size: image.size))

    let rect = CGRect(origin: point, size: image.size)
    text.draw(in: rect, withAttributes: textFontAttributes)

    let newImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

    return newImage!
 }

Answer 2

我的简单解决方案：

func generateImageWithText(text: String) -> UIImage
{
    let image = UIImage(named: "imageWithoutText")!

    let imageView = UIImageView(image: image)
    imageView.backgroundColor = UIColor.clearColor()
    imageView.frame = CGRectMake(0, 0, image.size.width, image.size.height)

    let label = UILabel(frame: CGRectMake(0, 0, image.size.width, image.size.height))
    label.backgroundColor = UIColor.clearColor()
    label.textAlignment = .Center
    label.textColor = UIColor.whiteColor()
    label.text = text

    UIGraphicsBeginImageContextWithOptions(label.bounds.size, false, 0);
    imageView.layer.renderInContext(UIGraphicsGetCurrentContext()!)
    label.layer.renderInContext(UIGraphicsGetCurrentContext()!)
    let imageWithText = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext();

    return imageWithText
}

Answer 3

您也可以执行CATextLayer。

    // 1
let textLayer = CATextLayer()
textLayer.frame = someView.bounds

// 2
var string = ""
for _ in 1...20 {
  string += "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Fusce auctor arcu quis velit congue dictum. "
}

textLayer.string = string

// 3
let fontName: CFStringRef = "Noteworthy-Light"
textLayer.font = CTFontCreateWithName(fontName, fontSize, nil)

// 4
textLayer.foregroundColor = UIColor.darkGrayColor().CGColor
textLayer.wrapped = true
textLayer.alignmentMode = kCAAlignmentLeft
textLayer.contentsScale = UIScreen.mainScreen().scale
someView.layer.addSublayer(textLayer)

http://www.raywenderlich.com/90488/calayer-in-ios-with-swift-10-examples

Answer 4

我已经创建了一个扩展程序，可以在任何地方使用它：

import Foundation
import UIKit
extension UIImage {

    class func createImageWithLabelOverlay(label: UILabel,imageSize: CGSize, image: UIImage) -> UIImage {
        UIGraphicsBeginImageContextWithOptions(CGSize(width: imageSize.width, height: imageSize.height), false, 2.0)
        let currentView = UIView.init(frame: CGRect(x: 0, y: 0, width: imageSize.width, height: imageSize.height))
        let currentImage = UIImageView.init(image: image)
        currentImage.frame = CGRect(x: 0, y: 0, width: imageSize.width, height: imageSize.height)
        currentView.addSubview(currentImage)
        currentView.addSubview(label)
        currentView.layer.render(in: UIGraphicsGetCurrentContext()!)
        let img = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return img!
    }

}

用法：可以在ViewController上具有大小和标签的任何地方使用它，如下所示-

let newImageWithOverlay = UIImage.createImageWithLabelOverlay(label: labelToAdd, imageSize: size, image: editedImage)

Answer 5

对于swift 4：

func textToImage(drawText text: NSString, inImage image: UIImage, atPoint point: CGPoint) -> UIImage {


    let scale = UIScreen.main.scale
    UIGraphicsBeginImageContextWithOptions(image.size, false, scale)

    image.draw(in: CGRect(origin: CGPoint.zero, size: image.size))

    let rect = CGRect(origin: point, size: image.size)

    let paragraphStyle = NSMutableParagraphStyle()
    paragraphStyle.alignment = .center



    let attrs = [NSAttributedStringKey.font: UIFont(name: "Helvetica Bold", size: 12)!,NSAttributedStringKey.foregroundColor : UIColor.white , NSAttributedStringKey.paragraphStyle: paragraphStyle]


    text.draw(with: rect, options: .usesLineFragmentOrigin, attributes: attrs, context: nil)



    let newImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

    return newImage!
}

Answer 6

在您的最初问题中，我看不到任何内容，提示必须仅在代码中完成此操作-为什么不在接口构建器中简单地添加UILabel，并添加约束使其具有与图像中心相同的长度和宽度垂直和水平放置（或放置），根据需要删除标签文本，设置文本字体，大小，颜色等（包括在Autoshrink上打上所需的最小尺寸或比例），并确保其背景是透明的。

然后将其连接到IBOutlet，并根据需要在代码中设置文本（例如，在viewWillAppear中，或使用ViewModel方法并在初始化视图/视图控制器时进行设置）。

Answer 7

我已经尝试过此基本组件。希望它能工作。

func imageWithText(image : UIImage, text : String) -> UIImage {

        let outerView = UIView(frame: CGRect(x: 0, y: 0, width: image.size.width / 2, height: image.size.height / 2))
        let imgView = UIImageView(frame: CGRect(x: 0, y: 0, width: outerView.frame.width, height: outerView.frame.height))
        imgView.image = image
        outerView.addSubview(imgView)

        let lbl = UILabel(frame: CGRect(x: 5, y: 5, width: outerView.frame.width, height: 200))
        lbl.font = UIFont(name: "HelveticaNeue-Bold", size: 70)
        lbl.text = text
        lbl.textAlignment = .left
        lbl.textColor = UIColor.blue

        outerView.addSubview(lbl)

        let renderer = UIGraphicsImageRenderer(size: outerView.bounds.size)
        let convertedImage = renderer.image { ctx in
            outerView.drawHierarchy(in: outerView.bounds, afterScreenUpdates: true)

        }
        return convertedImage
    }

Answer 8

也可以使用 QLPreviewController。只需将 imageFile 保存到 .userDomainMask 下的 ApplicationsDocuments 目录之类的 url 中，然后打开苹果的编辑器。您可以绘制、添加形状、箭头甚至您的签名。我在以下帖子中详细解释了实现： https://stackoverflow.com/a/68743098/12035498

如何在iOS Swift中为图像添加文本？

8 个答案:

对于swift 3：

对于swift 4：