Swift開婦捕獲使用者簽名（使用者在螢幕上手寫簽名，並產生圖片）

本文介紹如何使用Swift語言，在iOS裝置上捕捉使用者的簽名（其實這個本質就是一個簡單的畫圖板程式）。

 

實現功能如下：

1，頁面上方提供一個簽名地區（UIView），使用者可以在這個地區手寫簽字。

2，點擊“預覽簽名”，會擷取使用者簽名產生UIImage，在下方的imageView中顯示。

3，點擊“儲存簽名”，會將使用者簽名儲存到裝置相簿中。

 

效果圖如下： 

         

 

代碼如下：

--- DrawSignatureView.swift （簽名視圖組件） ---

代碼如下

複製代碼

import UIKit   public class DrawSignatureView: UIView {           // 公用屬性     public var lineWidth: CGFloat = 2.0 {         didSet {             self.path.lineWidth = lineWidth         }     }     public var strokeColor: UIColor = UIColor.blackColor()     public var signatureBackgroundColor: UIColor = UIColor.whiteColor()           // 私人屬性     private var path = UIBezierPath()     private var pts = [CGPoint](count: 5, repeatedValue: CGPoint())     private var ctr = 0           // Init     override init(frame: CGRect) {         super.init(frame: frame)                   self.backgroundColor = self.signatureBackgroundColor         self.path.lineWidth = self.lineWidth     }           // Init     required public init?(coder aDecoder: NSCoder) {         super.init(coder: aDecoder)                   self.backgroundColor = self.signatureBackgroundColor         self.path.lineWidth = self.lineWidth     }           // Draw     override public func drawRect(rect: CGRect) {         self.strokeColor.setStroke()         self.path.stroke()     }           // 觸摸簽名相關方法     override public func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {         if let firstTouch = touches.first{             let touchPoint = firstTouch.locationInView(self)             self.ctr = 0             self.pts[0] = touchPoint         }     }           override public func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {         if let firstTouch = touches.first{             let touchPoint = firstTouch.locationInView(self)             self.ctr++             self.pts[self.ctr] = touchPoint             if (self.ctr == 4) {                 self.pts[3] = CGPointMake((self.pts[2].x + self.pts[4].x)/2.0,                     (self.pts[2].y + self.pts[4].y)/2.0)                 self.path.moveToPoint(self.pts[0])                 self.path.addCurveToPoint(self.pts[3], controlPoint1:self.pts[1],                     controlPoint2:self.pts[2])                                   self.setNeedsDisplay()                 self.pts[0] = self.pts[3]                 self.pts[1] = self.pts[4]                 self.ctr = 1             }                           self.setNeedsDisplay()         }     }           override public func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {         if self.ctr == 0{             let touchPoint = self.pts[0]             self.path.moveToPoint(CGPointMake(touchPoint.x-1.0,touchPoint.y))             self.path.addLineToPoint(CGPointMake(touchPoint.x+1.0,touchPoint.y))             self.setNeedsDisplay()         } else {             self.ctr = 0         }     }           // 簽名視圖清空     public func clearSignature() {         self.path.removeAllPoints()         self.setNeedsDisplay()     }           // 將簽名儲存為UIImage     public func getSignature() ->UIImage {         UIGraphicsBeginImageContext(CGSizeMake(self.bounds.size.width,             self.bounds.size.height))         self.layer.renderInContext(UIGraphicsGetCurrentContext()!)         let signature: UIImage = UIGraphicsGetImageFromCurrentImageContext()         UIGraphicsEndImageContext()         return signature     } }

--- ViewController.swift （使用範例） ---

代碼如下

複製代碼

import UIKit   class ViewController: UIViewController {           //簽名預覽     @IBOutlet weak var imageView: UIImageView!           //簽名地區視圖     var drawView:DrawSignatureView!           override func viewDidLoad() {         super.viewDidLoad()                   //簽名地區位置尺寸         var drawViewFrame = self.view.bounds         drawViewFrame.size.height = 200         //添加簽名地區         drawView = DrawSignatureView(frame: drawViewFrame)         self.view.addSubview(drawView)                    }       //預覽簽名     @IBAction func previewSignature(sender: AnyObject) {         let signatureImage = self.drawView.getSignature()         imageView.image = signatureImage     }           //儲存簽名     @IBAction func savaSignature(sender: AnyObject) {         let signatureImage = self.drawView.getSignature()         UIImageWriteToSavedPhotosAlbum(signatureImage, nil, nil, nil)         self.drawView.clearSignature()     }           //清除簽名     @IBAction func clearSignature(sender: AnyObject) {         self.drawView.clearSignature()         self.imageView.image = nil     }           override func didReceiveMemoryWarning() {         super.didReceiveMemoryWarning()     } }