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如何在Swift中将文本(字符串)转换为图像(UIImage)?

uiimage uikit string swift ios

Geoff · 技术社区 · 8 年前

我今天更新了Xcode,cocoa pod,alamofire,alamofireimage,

现在我的代码上有一个关于文字到图像的红色标记。

我是一个编程新手。

func textToImage(drawText text: NSString, inImage image: UIImage, atPoint point: CGPoint) -> UIImage {
    let textColor = UIColor.red
    let textFont = UIFont(name: "Arial Rounded MT Bold", size: 24)!

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

    let textFontAttributes = [
        NSAttributedStringKey.font.rawValue: textFont,
        NSAttributedStringKey.foregroundColor: 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!
}

ligne中的红色品牌comme

text.draw(in: rect, withAttributes: textFontAttributes )

消息:无法将类型为“[String:Any]”的值转换为预期的参数类型“[NSAttributedStringKey:Any]?”

1 回复 | 直到 4 年前

Leo Dabus 8 年前

您的代码有一些问题。首先不要使用NSString,Swift本机字符串类型为string。其次,您需要将textFontAttributes类型指定为 [NSAttributedStringKey: Any] 不要强行打开结果。将返回类型更改为可选图像UIImage?当方法完成时,也可以使用“延时到结束”图形图像上下文。

func textToImage(drawText text: String, inImage image: UIImage, atPoint point: CGPoint) -> UIImage? {
    let textColor: UIColor = .red
    let textFont = UIFont(name: "Arial Rounded MT Bold", size: 24)!
    let scale = UIScreen.main.scale
    UIGraphicsBeginImageContextWithOptions(image.size, false, scale)
    defer { UIGraphicsEndImageContext() }
    let textFontAttributes: [NSAttributedStringKey: Any] = [.font: textFont, .foregroundColor: textColor]
    image.draw(in: CGRect(origin: .zero, size: image.size))
    let rect = CGRect(origin: point, size: image.size)
    text.draw(in: rect, withAttributes: textFontAttributes)
    return UIGraphicsGetImageFromCurrentImageContext()
}

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