将 Apple Emoji（字符串）转换为 UIImage

Question

我需要所有的 Apple Emojis。
我可以得到所有的 emojis 并通过从站点 getemoji 复制它们将它们放入 String 但是在我的应用程序中，我需要按正确顺序排列的表情符号 as images.

有什么好的方法可以将我复制到字符串中的表情符号转换为 UIImage?
或者以正确的顺序获取所有 Apple 表情符号的更好解决方案？

Answer 1

更新为 Swift 4.1

将此扩展程序添加到您的项目中

import UIKit

extension String {
    func image() -> UIImage? {
        let size = CGSize(width: 40, height: 40)
        UIGraphicsBeginImageContextWithOptions(size, false, 0)
        UIColor.white.set()
        let rect = CGRect(origin: .zero, size: size)
        UIRectFill(CGRect(origin: .zero, size: size))
        (self as AnyObject).draw(in: rect, withAttributes: [.font: UIFont.systemFont(ofSize: 40)])
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image
    }
}

上面的代码将当前的 String 绘制到背景色为白色的图像上下文中，最后将其转换为 UIImage。

现在你可以写了

例子

给定一个范围列表，指示表情符号的 unicode 值

let ranges = [0x1F601...0x1F64F, 0x2702...0x27B0]

您可以将其转换为图像列表

let images = ranges
    .flatMap { [=12=] }
    .compactMap { Unicode.Scalar([=12=]) }
    .map(Character.init)
    .compactMap { String([=12=]).image() }

结果：

I cannot guarantee the list of ranges is complete, you'll need to search for it by yourself

Answer 2

已更新 @Luca Angeletti Swift 3.0.1

的答案

extension String {

    func image() -> UIImage? {
        let size = CGSize(width: 30, height: 35)
        UIGraphicsBeginImageContextWithOptions(size, false, 0);
        UIColor.white.set()
        let rect = CGRect(origin: CGPoint(), size: size)
        UIRectFill(CGRect(origin: CGPoint(), size: size))
        (self as NSString).draw(in: rect, withAttributes: [NSFontAttributeName: UIFont.systemFont(ofSize: 30)])
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image
    }

}

Answer 3

Swift 4 也一样：

extension String {
    func emojiToImage() -> UIImage? {
        let size = CGSize(width: 30, height: 35)
        UIGraphicsBeginImageContextWithOptions(size, false, 0)
        UIColor.white.set()
        let rect = CGRect(origin: CGPoint(), size: size)
        UIRectFill(rect)
        (self as NSString).draw(in: rect, withAttributes: [NSAttributedStringKey.font: UIFont.systemFont(ofSize: 30)])
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image
    }
}

Answer 4

Swift 4.2

我真的很喜欢@Luca Angeletti 的解决方案。关于透明背景，我和@jonauz 有同样的问题。因此，通过这个小修改，您可以获得相同的结果，但背景颜色清晰。

我没有代表在评论中回答。

import UIKit

extension String {
    func emojiToImage() -> UIImage? {
        let size = CGSize(width: 30, height: 35)
        UIGraphicsBeginImageContextWithOptions(size, false, 0)
        UIColor.clear.set()
        let rect = CGRect(origin: CGPoint(), size: size)
        UIRectFill(CGRect(origin: CGPoint(), size: size))
        (self as NSString).draw(in: rect, withAttributes: [NSAttributedString.Key.font: UIFont.systemFont(ofSize: 30)])
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image
    }
}

Answer 5

这是经过以下更改的更新答案：

Centered：使用 draw(at:withAttributes:) instead of draw(in:withAttributes:) 将生成的 UIImage
正确大小：使用size(withAttributes:) 生成大小与字体实际大小相关的 UIImage。
评论：添加评论以便更好地理解

Swift 5

import UIKit
extension String {
    func textToImage() -> UIImage? {
        let nsString = (self as NSString)
        let font = UIFont.systemFont(ofSize: 1024) // you can change your font size here
        let stringAttributes = [NSAttributedString.Key.font: font]
        let imageSize = nsString.size(withAttributes: stringAttributes)

        UIGraphicsBeginImageContextWithOptions(imageSize, false, 0) //  begin image context
        UIColor.clear.set() // clear background
        UIRectFill(CGRect(origin: CGPoint(), size: imageSize)) // set rect size
        nsString.draw(at: CGPoint.zero, withAttributes: stringAttributes) // draw text within rect
        let image = UIGraphicsGetImageFromCurrentImageContext() // create image from context
        UIGraphicsEndImageContext() //  end image context

        return image ?? UIImage()
    }
}

Swift3.2

import UIKit
extension String {
    func textToImage() -> UIImage? {
        let nsString = (self as NSString)
        let font = UIFont.systemFont(ofSize: 1024) // you can change your font size here
        let stringAttributes = [NSFontAttributeName: font]
        let imageSize = nsString.size(attributes: stringAttributes)

        UIGraphicsBeginImageContextWithOptions(imageSize, false, 0) //  begin image context
        UIColor.clear.set() // clear background
        UIRectFill(CGRect(origin: CGPoint(), size: imageSize)) // set rect size
        nsString.draw(at: CGPoint.zero, withAttributes: stringAttributes) // draw text within rect
        let image = UIGraphicsGetImageFromCurrentImageContext() // create image from context
        UIGraphicsEndImageContext() //  end image context

        return image ?? UIImage()
    }
}

Answer 6

@Luca Angeletti 的答案更新版本使用 UIGraphicsImageRenderer:

extension String {
    func image() -> UIImage? {
        let size = CGSize(width: 100, height: 100)
        let rect = CGRect(origin: CGPoint(), size: size)
        return UIGraphicsImageRenderer(size: size).image { (context) in
            (self as NSString).draw(in: rect, withAttributes: [.font : UIFont.systemFont(ofSize: 100)])
        }
    }
}

Answer 7

此变体基于已接受的答案，但允许您有选择地自定义字体的磅值，应使图像居中，并且不会使背景颜色变白。

extension String {
    func image(pointSize: CGFloat = UIFont.systemFontSize) -> UIImage? {
        let nsString = self as NSString
        let font = UIFont.systemFont(ofSize: pointSize)

        let size = nsString.size(withAttributes: [.font: font])
        UIGraphicsBeginImageContextWithOptions(size, false, 0)
        let rect = CGRect(origin: .zero, size: size)
        nsString.draw(in: rect, withAttributes: [.font: font])
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image
    }
}

Answer 8

Swift 5:（可选字体大小、图像大小和背景颜色）

像这样使用它：

let image      = "".image()
let imageLarge = "".image(fontSize:100)
let imageBlack = "".image(fontSize:100, bgColor:.black)
let imageLong  = "".image(fontSize:100, imageSize:CGSize(width:500,height:100))


import UIKit

extension String
{
    func image(fontSize:CGFloat = 40, bgColor:UIColor = UIColor.clear, imageSize:CGSize? = nil) -> UIImage?
    {
        let font = UIFont.systemFont(ofSize: fontSize)
        let attributes = [NSAttributedString.Key.font: font]
        let imageSize = imageSize ?? self.size(withAttributes: attributes)

        UIGraphicsBeginImageContextWithOptions(imageSize, false, 0)
        bgColor.set()
        let rect = CGRect(origin: .zero, size: imageSize)
        UIRectFill(rect)
        self.draw(in: rect, withAttributes: [.font: font])
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image
    }
}

将 Apple Emoji（字符串）转换为 UIImage

Convert Apple Emoji (String) to UIImage

ios

emoji

swift

更新为 Swift 4.1

例子

Swift 4.2