我环顾四周,但未能成功弄清楚如何获取文本,将其覆盖在图像上,然后将两者组合成一个 UIImage
。
我已经用尽了谷歌我能想到的搜索词,所以如果有人有解决方案或至少可以指出它的提示,我们将不胜感激。
最佳答案
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,您只需传入图像即可:
textToImage("000", inImage: UIImage(named:"thisImage.png")!, atPoint: CGPointMake(20, 20))
以下链接帮助我弄清楚了这一点:
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可以在 AnnotationView
中使用的动态图像,例如在 map 上的给定位置放置价格,这非常适合。
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!
}
对于 Swift 5:
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 = [
NSAttributedString.Key.font: textFont,
NSAttributedString.Key.foregroundColor: textColor,
] as [NSAttributedString.Key : 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!
}
关于ios - 如何在 iOS Swift 中向图像添加文本?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/43782899/