Question

我想知道如何像在电话上一样保存我的应用程序的图形，然后将其发送到服务器。

这是我的代码。

我在这堂课上画画。

import Foundation
import UIKit

class Sign: UIViewController
{
@IBOutlet weak var btnSave: UIButton!
@IBOutlet weak var btnClear: UIButton!

let canvas  = Canvas()

fileprivate func setupLayout() {
    let stackView = UIStackView(arrangedSubviews: [btnClear,btnSave])

    view.addSubview(stackView)

    stackView.distribution = .fillEqually
    stackView.translatesAutoresizingMaskIntoConstraints = false
    stackView.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
    stackView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
    stackView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
}

override func viewDidLoad() {
    view.addSubview(canvas)
    canvas.backgroundColor = .white
    canvas.frame = view.frame

    setupLayout()


}
@IBAction func ClearCanvas(_ sender: Any) {
    canvas.clear()        
}

@IBAction func SaveCanvas(_ sender: Any) {

}
}

我也有这个Canvas类，其中有按钮的功能。只想知道如何处理我的视图或将其与绘图转换为图像并将其保存，然后将其发送到服务器。

import Foundation
import UIKit

class Canvas: UIView {

func clear(){
    lines.removeAll()
    setNeedsDisplay()
}
override func draw(_ rect: CGRect) {

    guard let context = UIGraphicsGetCurrentContext() else {return}

    context.setStrokeColor(UIColor.black.cgColor)
    context.setLineWidth(5)
    context.setLineCap(.butt)

    lines.forEach { (line) in
        for (i , p) in line.enumerated(){
            if i == 0 {
                context.move(to: p)
            } else {
                context.addLine(to: p)
            }
        }
    }


    context.strokePath()

}

var lines = [[CGPoint]]()

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    lines.append([CGPoint]())
}

override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    guard let point = touches.first?.location(in: nil) else {return}

    guard var lastline = lines.popLast() else { return }
    lastline.append(point)
    lines.append(lastline)

    setNeedsDisplay()
}
}

Answer 1

您可以在类Canvas中添加一个函数来绘制图像并将图像数据更新到服务器。

func screenShot() -> UIImage? {
    //Create the UIImage
    UIGraphicsBeginImageContext(self.frame.size)
    self.layer.renderInContext(UIGraphicsGetCurrentContext())
    let image = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return image
}

Answer 2

当您在名为Canvas的视图中绘制了所有内容后，为什么不将其转换为像截图一样的图像呢？

以下是UIView的扩展，具有名为屏幕快照的计算属性，它将为您提供所需的图像：-

extension UIView {
    var screenshot : UIImage? {
        var screenshot :UIImage?
        let scale = UIScreen.main.scale
        UIGraphicsBeginImageContextWithOptions(layer.frame.size, false, scale);
        guard let context = UIGraphicsGetCurrentContext() else {return nil}
        layer.render(in:context)
        screenshot = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return screenshot
    }
}

使用方法：-

@IBAction func SaveCanvas(_ sender: Any) {
   let drawing = canvas.screenshot
   //Now send this image to server
}

保存图形并将其发送到服务器swift

2 个答案: