iOS 简易的画板
//截取制定view 将其转成UIImage
class func getAppImage(view:UIView) -> UIImage {
UIGraphicsBeginImageContext(view.frame.size)
let context = UIGraphicsGetCurrentContext()
view.layer.renderInContext(context!)
let screenimg:UIImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return screenimg
}
///保存到相册
func showImage() {
drawimageView.image = AppDelegate.getAppImage(drawview)
if let i = drawimageView.image {
UIImageWriteToSavedPhotosAlbum(i, nil, nil, nil)
}
}
class DrawView: UIView {
//声明一个贝塞尔曲线
var path:UIBezierPath!
var previousPoint:CGPoint!
///手势是否被激活
var panGRBool:Bool = false
override init(frame: CGRect) {
super.init(frame: frame)
self.backgroundColor = UIColor.whiteColor()
initGesture()
initBezierPath()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
//创建一个拖动的手势
func initGesture() {
let pan = UIPanGestureRecognizer(target: self,action: #selector(DrawView.panGRclick(_:)))
pan.maximumNumberOfTouches = 1
self.addGestureRecognizer(pan)
}
func initBezierPath() {
path = UIBezierPath()
}
///手势是否所以需要用被激活件 来进行初始的判断如果通过手势响应事件
因为刚开始滑动时不会相应sender.state == UIGestureRecognizerState.Began
势是否被所以需要用 touches 事件 来进行初始的判断如果通过 panGRBool 来判断是否拖动手势被激活
func panGRclick(sender:UIPanGestureRecognizer) {
let point = sender.locationInView(self)
let newpoint = getNewPoint(previousPoint, maxpo: point)
if sender.state == UIGestureRecognizerState.Began {
panGRBool = true
path.addLineToPoint(point)
}else if sender.state == UIGestureRecognizerState.Changed {
if let n = newpoint {
///画弧线
path.addQuadCurveToPoint(n, controlPoint: previousPoint)
}else {
path.addLineToPoint(point)
}
}
if sender.state == UIGestureRecognizerState.Ended {
panGRBool = false
}
previousPoint = point
self.setNeedsDisplay()
}
override func drawRect(rect: CGRect) {
UIColor.redColor().setStroke()
path.stroke()
}
func getNewPoint(minpo:CGPoint?,maxpo:CGPoint) -> CGPoint? {
if let p = minpo {
return CGPoint(
x: (p.x + maxpo.x)/2.0,
y: (p.y + maxpo.y)/2.0
)
}
return nil
}
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
if let touch = (touches as NSSet).anyObject() {
let point = touch.locationInView(self)
path.moveToPoint(point)
}
}
override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
if let touch = (touches as NSSet).anyObject() {
if !panGRBool {
let point = touch.locationInView(self)
path.addLineToPoint(point)
self.setNeedsDisplay()
}
}
}
}