本文介绍了使用swift在图像上叠加文本的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我正在尝试使用Swift在图像上叠加一些文本,我在这里查看此代码:(src:
func sample2(label:UILabel){
im ageView.image = UIImage(名称:wall)
imageView.contentMode = .scaleAspectFit
imageView.drawOnCurrentImage(view:label,mode:.changeOriginalImage){$ parentSize,viewToAdd in
print(parentSize:\(parentSize))
viewToAdd.font = UIFont.systemFont(ofSize:40)
viewToAdd.textColor = .yellow
viewToAdd.textAlignment = .right
let width:CGFloat = 200
let height:CGFloat = 30
let indent:CGFloat = 40
viewToAdd.bounds = CGRect(x:parentSize.width - width - indent,y: parentSize.height - height - indent,width:width,height:height)
}
}
func sample3(label:UILabel){
imageView.image = UIImage(名称:wall)
imageView.contentMode = .scaleAspectFill
imageView.drawOnCurrentImage(view:label,mode:.addSubview){(parentSize,viewToAdd)in
print(parentSize:\(parentSize))
viewToAdd.font = UIFont.systemFont(ofSize:16)
viewToAdd.textColor = .yellow
viewToAdd.frame = CGRect(x: 40,y:40,宽度:200,身高:20)
}
}
import UIKit
class ViewController:UIViewController {
let imageView = UIImageView(frame:CGRect(x:50,y:50,width:300,height:300))
override func viewDidLoad(){
super.viewDidLoad()
//加载视图后进行任何其他设置,通常是从nib。
let label = UILabel(frame:CGRect(x:20,y:20,width:80,height:30))
label.text =Blablabla
label.font = UIFont .systemFont(ofSize:20)
label.textColor = .black
view.addSubview(label)
sample1(label:label)
// sample2(label :label)
// sample3(标签:标签)
// sample4(标签:标签)
imageView.clipsToBounds = true
view.addSubview(imageView)
}
func sample1(标签:UILabel){
imageView.contentMode = .scaleAspectFit
imageView.image = UIImage(名称:wall)?。with (view:label)$(b)中的{(parentSize,viewToAdd)print(parentSize:\(parentSize))
viewToAdd.font = UIFont.systemFont(ofSize:40)
viewToAdd。 textColor = .yellow
viewToAdd.bounds = CGRect(x:40,y:40,width:200,height:20)
}
}
fun c sample2(label:UILabel){
imageView.image = UIImage(named:wall)
imageView.contentMode = .scaleAspectFit
imageView.drawOnCurrentImage(view:label,mode:.changeOriginalImage )$(b)中的{(parentSize,viewToAdd)print(parentSize:\(parentSize))
viewToAdd.font = UIFont.systemFont(ofSize:40)
viewToAdd.textColor = .yellow
viewToAdd.textAlignment = .right
let width:CGFloat = 200
let height:CGFloat = 30
let indent:CGFloat = 40
viewToAdd.bounds = CGRect( x:parentSize.width - width - indent,y:parentSize.height - height - indent,width:width,height:height)
}
}
func sample3(label :UILabel){
imageView.image = UIImage(命名:wall)
imageView.contentMode = .scaleAspectFill
imageView.drawOnCurrentImage(view:label,mode:.addSubview){(p
打印中的arentSize,viewToAdd)(parentSize:\(parentSize))
viewToAdd.font = UIFont.systemFont(ofSize:16)
viewToAdd.textColor = .yellow
viewToAdd.frame = CGRect(x:40,y:40,width:200,height:20)
}
}
func sample4(label:UILabel){
imageView.image = UIImage(名称:wall)
imageView.contentMode = .scaleAspectFill
imageView.drawOnCurrentImage(view:label,mode:.addCopiedSubview){(parentSize,viewToAdd)in
print(parentSize:\(parentSize))
viewToAdd.font = UIFont.systemFont(ofSize:16)
viewToAdd.textColor = .yellow
viewToAdd.frame = CGRect (x:40,y:40,宽度:200,身高:20)
}
}
}
I am trying to overlay some text on an image using Swift and am looking at this code here: (src: How do I add text to an image in iOS Swift)
This places the text right in the center. I have been changing the values in
var rect = CGRectMake(10,150, inImage.size.width,
inImage.size.height)
but I am unable to get the text to show in the lower left corner. Can someone help and show what I am missing here ?
I am adding the modified image using this line:
modImage = self.textToImage("000", inImage: UIImage(named:"thisImage.png")!, atPoint: CGPointMake(10, 400))
Below is the function...
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
}
解决方案
Details
xCode 9.1, Swift 4
Solution
extension UIView {
func copyObject<T: UIView> () -> T? {
let archivedData = NSKeyedArchiver.archivedData(withRootObject: self)
return NSKeyedUnarchiver.unarchiveObject(with: archivedData) as? T
}
}
extension UIImage {
typealias EditSubviewClosure<T: UIView> = (_ parentSize: CGSize, _ viewToAdd: T)->()
func with<T: UIView>(view: T, editSubviewClosure: EditSubviewClosure<T>) -> UIImage {
if let copiedView = view.copyObject() as? T {
UIGraphicsBeginImageContext(size)
let basicSize = CGRect(origin: .zero, size: size)
draw(in: basicSize)
editSubviewClosure(size, copiedView)
copiedView.draw(basicSize)
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage!
}
return self
}
}
extension UIImageView {
enum ImageAddingMode {
case changeOriginalImage
case addSubview
case addCopiedSubview
}
func drawOnCurrentImage<T: UIView>(view: T, mode: ImageAddingMode, editSubviewClosure: @escaping UIImage.EditSubviewClosure<T>) {
guard let image = image else {
return
}
let addSubView: (T) -> () = { view in
editSubviewClosure(self.frame.size, view)
self.addSubview(view)
}
switch mode {
case .changeOriginalImage:
self.image = image.with(view: view, editSubviewClosure: editSubviewClosure)
case .addSubview:
addSubView(view)
case .addCopiedSubview:
if let copiedView = view.copyObject() as? T {
addSubView(copiedView)
}
}
}
}
Usage
func sample1(label: UILabel) {
imageView.contentMode = .scaleAspectFit
imageView.image = UIImage(named: "wall")?.with(view: label) { (parentSize, viewToAdd) in
print("parentSize: \(parentSize)")
viewToAdd.font = UIFont.systemFont(ofSize: 40)
viewToAdd.textColor = .yellow
viewToAdd.bounds = CGRect(x: 40, y: 40, width: 200, height: 40)
}
}
func sample2(label: UILabel) {
imageView.image = UIImage(named: "wall")
imageView.contentMode = .scaleAspectFit
imageView.drawOnCurrentImage(view: label, mode: .changeOriginalImage) { (parentSize, viewToAdd) in
print("parentSize: \(parentSize)")
viewToAdd.font = UIFont.systemFont(ofSize: 40)
viewToAdd.textColor = .yellow
viewToAdd.textAlignment = .right
let width: CGFloat = 200
let height: CGFloat = 30
let indent: CGFloat = 40
viewToAdd.bounds = CGRect(x: parentSize.width - width - indent, y: parentSize.height - height - indent, width: width, height: height)
}
}
func sample3(label: UILabel) {
imageView.image = UIImage(named: "wall")
imageView.contentMode = .scaleAspectFill
imageView.drawOnCurrentImage(view: label, mode: .addSubview) { (parentSize, viewToAdd) in
print("parentSize: \(parentSize)")
viewToAdd.font = UIFont.systemFont(ofSize: 16)
viewToAdd.textColor = .yellow
viewToAdd.frame = CGRect(x: 40, y: 40, width: 200, height: 20)
}
}
func sample4(label: UILabel) {
imageView.image = UIImage(named: "wall")
imageView.contentMode = .scaleAspectFill
imageView.drawOnCurrentImage(view: label, mode: .addCopiedSubview) { (parentSize, viewToAdd) in
print("parentSize: \(parentSize)")
viewToAdd.font = UIFont.systemFont(ofSize: 16)
viewToAdd.textColor = .yellow
viewToAdd.frame = CGRect(x: 40, y: 40, width: 200, height: 20)
}
}
Full sample
import UIKit
class ViewController: UIViewController {
let imageView = UIImageView(frame: CGRect(x: 50, y: 50, width: 300, height: 300))
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
let label = UILabel(frame: CGRect(x: 20, y: 20, width: 80, height: 30))
label.text = "Blablabla"
label.font = UIFont.systemFont(ofSize: 20)
label.textColor = .black
view.addSubview(label)
sample1(label: label)
//sample2(label: label)
//sample3(label: label)
//sample4(label: label)
imageView.clipsToBounds = true
view.addSubview(imageView)
}
func sample1(label: UILabel) {
imageView.contentMode = .scaleAspectFit
imageView.image = UIImage(named: "wall")?.with(view: label) { (parentSize, viewToAdd) in
print("parentSize: \(parentSize)")
viewToAdd.font = UIFont.systemFont(ofSize: 40)
viewToAdd.textColor = .yellow
viewToAdd.bounds = CGRect(x: 40, y: 40, width: 200, height: 20)
}
}
func sample2(label: UILabel) {
imageView.image = UIImage(named: "wall")
imageView.contentMode = .scaleAspectFit
imageView.drawOnCurrentImage(view: label, mode: .changeOriginalImage) { (parentSize, viewToAdd) in
print("parentSize: \(parentSize)")
viewToAdd.font = UIFont.systemFont(ofSize: 40)
viewToAdd.textColor = .yellow
viewToAdd.textAlignment = .right
let width: CGFloat = 200
let height: CGFloat = 30
let indent: CGFloat = 40
viewToAdd.bounds = CGRect(x: parentSize.width - width - indent, y: parentSize.height - height - indent, width: width, height: height)
}
}
func sample3(label: UILabel) {
imageView.image = UIImage(named: "wall")
imageView.contentMode = .scaleAspectFill
imageView.drawOnCurrentImage(view: label, mode: .addSubview) { (parentSize, viewToAdd) in
print("parentSize: \(parentSize)")
viewToAdd.font = UIFont.systemFont(ofSize: 16)
viewToAdd.textColor = .yellow
viewToAdd.frame = CGRect(x: 40, y: 40, width: 200, height: 20)
}
}
func sample4(label: UILabel) {
imageView.image = UIImage(named: "wall")
imageView.contentMode = .scaleAspectFill
imageView.drawOnCurrentImage(view: label, mode: .addCopiedSubview) { (parentSize, viewToAdd) in
print("parentSize: \(parentSize)")
viewToAdd.font = UIFont.systemFont(ofSize: 16)
viewToAdd.textColor = .yellow
viewToAdd.frame = CGRect(x: 40, y: 40, width: 200, height: 20)
}
}
}
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