如何调整正在打印的图像的大小?
How to resize an image that is being printed?
我正在尝试打印由 Swift 生成的 QR 码,当我打印出来时它占据了整个 sheet 我想调整图像大小并使其变小.大约 200px x 200px
我试过使用不同的 UIImage 调整大小功能,结果仍然一样。我还尝试使用 printController
调整图像大小
func printImage(img:UIImage) {
let printController = UIPrintInteractionController.shared
let printInfo = UIPrintInfo(dictionary:nil)
printInfo.jobName = "Printing \(myTextField.text) 's QR code"
printInfo.outputType = .photoGrayscale
self.resizeImage(img, targetSize: CGSizeMake(200.0, 200.0))
printController.printInfo = printInfo
printController.printingItem = img
printController.present(animated: true) { (_, isPrinted, error) in
if error == nil {
if isPrinted {
print("QR Code Has Been Printed :)")
} else {
print("QR Code Not Printed")
}
}
}
}
func resizeImage(image: UIImage, targetSize: CGSize) -> UIImage {
let size = image.size
let widthRatio = targetSize.width / size.width
let heightRatio = targetSize.height / size.height
// Figure out what our orientation is, and use that to form the rectangle
var newSize: CGSize
if(widthRatio > heightRatio) {
newSize = CGSizeMake(size.width * heightRatio, size.height * heightRatio)
} else {
newSize = CGSizeMake(size.width * widthRatio, size.height * widthRatio)
}
// This is the rect that we've calculated out and this is what is actually used below
let rect = CGRectMake(0, 0, newSize.width, newSize.height)
// Actually do the resizing to the rect using the ImageContext stuff
UIGraphicsBeginImageContextWithOptions(newSize, false, 1.0)
image.drawInRect(rect)
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage
}
我期待一个大约 200 像素 x 200 像素的小 QR 码。我目前正在收到 A4 尺寸的 QR 码
由于方法 resizeImage
正在返回新的 UIImage
您需要
的存储结果
self.resizeImage(img, targetSize: CGSizeMake(200.0, 200.0))
在另一个对象中,例如:
let resizedImage = self.resizeImage(img, targetSize: CGSizeMake(200.0, 200.0))
现在您可以使用此 resizedImage
图像进行打印,例如:
printController.printingItem = resizedImage
希望这会有所帮助。
编辑:
更新代码如下:
func printImage(img:UIImage) {
let printController = UIPrintInteractionController.shared
let printInfo = UIPrintInfo(dictionary:nil)
printInfo.jobName = "Printing 's QR code"
printInfo.outputType = .photoGrayscale
if let resizedImage = self.resizeImage(image: img, targetSize: CGSize(width: 200, height: 200)) {
printController.printInfo = printInfo
printController.printingItem = resizedImage
printController.present(animated: true) { (_, isPrinted, error) in
if error == nil {
if isPrinted {
print("QR Code Has Been Printed :)")
} else {
print("QR Code Not Printed")
}
}
}
}
}
func resizeImage(image: UIImage, targetSize: CGSize) -> UIImage? {
let size = image.size
let widthRatio = targetSize.width / size.width
let heightRatio = targetSize.height / size.height
// Figure out what our orientation is, and use that to form the rectangle
var newSize: CGSize
if(widthRatio > heightRatio) {
newSize = CGSize(width: size.width * heightRatio, height: size.height * heightRatio)
} else {
newSize = CGSize(width: size.width * widthRatio, height: size.height * widthRatio)
}
// This is the rect that we've calculated out and this is what is actually used below
let rect = CGRect(x: 0, y: 0, width: newSize.width, height: newSize.height)
// Actually do the resizing to the rect using the ImageContext stuff
UIGraphicsBeginImageContextWithOptions(newSize, false, 1.0)
image.draw(in: rect)
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage
}
我正在尝试打印由 Swift 生成的 QR 码,当我打印出来时它占据了整个 sheet 我想调整图像大小并使其变小.大约 200px x 200px
我试过使用不同的 UIImage 调整大小功能,结果仍然一样。我还尝试使用 printController
调整图像大小func printImage(img:UIImage) {
let printController = UIPrintInteractionController.shared
let printInfo = UIPrintInfo(dictionary:nil)
printInfo.jobName = "Printing \(myTextField.text) 's QR code"
printInfo.outputType = .photoGrayscale
self.resizeImage(img, targetSize: CGSizeMake(200.0, 200.0))
printController.printInfo = printInfo
printController.printingItem = img
printController.present(animated: true) { (_, isPrinted, error) in
if error == nil {
if isPrinted {
print("QR Code Has Been Printed :)")
} else {
print("QR Code Not Printed")
}
}
}
}
func resizeImage(image: UIImage, targetSize: CGSize) -> UIImage {
let size = image.size
let widthRatio = targetSize.width / size.width
let heightRatio = targetSize.height / size.height
// Figure out what our orientation is, and use that to form the rectangle
var newSize: CGSize
if(widthRatio > heightRatio) {
newSize = CGSizeMake(size.width * heightRatio, size.height * heightRatio)
} else {
newSize = CGSizeMake(size.width * widthRatio, size.height * widthRatio)
}
// This is the rect that we've calculated out and this is what is actually used below
let rect = CGRectMake(0, 0, newSize.width, newSize.height)
// Actually do the resizing to the rect using the ImageContext stuff
UIGraphicsBeginImageContextWithOptions(newSize, false, 1.0)
image.drawInRect(rect)
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage
}
我期待一个大约 200 像素 x 200 像素的小 QR 码。我目前正在收到 A4 尺寸的 QR 码
由于方法 resizeImage
正在返回新的 UIImage
您需要
self.resizeImage(img, targetSize: CGSizeMake(200.0, 200.0))
在另一个对象中,例如:
let resizedImage = self.resizeImage(img, targetSize: CGSizeMake(200.0, 200.0))
现在您可以使用此 resizedImage
图像进行打印,例如:
printController.printingItem = resizedImage
希望这会有所帮助。
编辑:
更新代码如下:
func printImage(img:UIImage) {
let printController = UIPrintInteractionController.shared
let printInfo = UIPrintInfo(dictionary:nil)
printInfo.jobName = "Printing 's QR code"
printInfo.outputType = .photoGrayscale
if let resizedImage = self.resizeImage(image: img, targetSize: CGSize(width: 200, height: 200)) {
printController.printInfo = printInfo
printController.printingItem = resizedImage
printController.present(animated: true) { (_, isPrinted, error) in
if error == nil {
if isPrinted {
print("QR Code Has Been Printed :)")
} else {
print("QR Code Not Printed")
}
}
}
}
}
func resizeImage(image: UIImage, targetSize: CGSize) -> UIImage? {
let size = image.size
let widthRatio = targetSize.width / size.width
let heightRatio = targetSize.height / size.height
// Figure out what our orientation is, and use that to form the rectangle
var newSize: CGSize
if(widthRatio > heightRatio) {
newSize = CGSize(width: size.width * heightRatio, height: size.height * heightRatio)
} else {
newSize = CGSize(width: size.width * widthRatio, height: size.height * widthRatio)
}
// This is the rect that we've calculated out and this is what is actually used below
let rect = CGRect(x: 0, y: 0, width: newSize.width, height: newSize.height)
// Actually do the resizing to the rect using the ImageContext stuff
UIGraphicsBeginImageContextWithOptions(newSize, false, 1.0)
image.draw(in: rect)
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage
}