将Apple Emoji（字符串）转换为UIImage

Question

我需要所有 Apple 表情符号。
我可以获取所有表情符号，然后通过从网站 getemoji 复制它们将它们放入 String 中，但在我的应用程序中，我需要按正确顺序的表情符号作为图像。

有没有一种好方法可以将我复制到字符串中的表情符号转换为UIImage？
或者有更好的解决方案让所有 Apple 表情符号按正确的顺序排列？

Answer 1

更新为 Swift 4.1

将此扩展添加到您的项目中

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

绘制到具有白色背景颜色的图像上下文中，最后将其转换为

UIImage

。

现在你可以写了

示例

给出表示表情符号的 unicode 值的范围列表

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

您可以将其转换为图像列表

let images = ranges
    .flatMap { $0 }
    .compactMap { Unicode.Scalar($0) }
    .map(Character.init)
    .compactMap { String($0).image() }

结果：

我不能保证范围列表完整，你需要自己搜索😉

Answer 2

这是经过以下更改的更新答案：

• Centered：使用

  draw(at:withAttributes:)

  而不是

  draw(in:withAttributes:)

  将文本在生成的 UIImage 中居中
• 正确大小：使用

  size(withAttributes:)

  获得尺寸与字体实际大小相关的结果 UIImage。
• 评论：添加评论以更好地理解

斯威夫特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()
    }
}

斯威夫特3.2

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 3

Swift 4 也是如此：

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

更新了 @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 5

斯威夫特 4.2

我真的很喜欢@Luca Angeletti 解决方案。我和@jonauz 有同样的问题关于透明背景。因此，通过这个小修改，您会得到相同的结果，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 6

Swift 5：（带有可选的 fontSize、imageSize 和 bgColor）

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
    }
}

Answer 7

使用

UIGraphicsImageRenderer

更新了 @Luca Angeletti 答案的版本：

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 8

此变体基于 @Luca's 接受的答案，但允许您选择自定义字体的点大小，应产生居中图像，并且不会使背景色变为白色。

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 9

实际上比建议的答案简单得多。

extension String {
    func image(pointSize: CGFloat, backgroundColor: UIColor = .clear) -> UIImage {
        let font = UIFont.systemFont(ofSize: pointSize)
        let emojiSize = self.size(withAttributes: [.font: font])

        return UIGraphicsImageRenderer(size: emojiSize).image { context in
            backgroundColor.setFill()
            context.fill(CGRect(origin: .zero, size: emojiSize))
            self.draw(at: .zero, withAttributes: [.font: font])
        }
    }
}