4.Swift 自定义View

4.Swift 自定义View

绘制线条

import UIKit

func UIGraphicsGetCurrentContext() -> CGContext

CGContext.CGContextMoveToPoint(c: CGContext?, _ x: CGFloat, _ y: CGFloat)

CGContext.CGContextAddLineToPoint(c: CGContext?, _ x: CGFloat, _ y: CGFloat)

CGContext.CGContextSetRGBStrokeColor(c: CGContext?, _ red: CGFloat, _ green: CGFloat, _ blue: CGFloat, _ alpha: CGFloat)

CGContext.CGContextSetLineWidth(c: CGContext?, _ width: CGFloat)

CGContext.CGContextStrokePath(c: CGContext?)

class DrawLinesView: UIView {

required init(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)!
}

// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
override func drawRect(rect: CGRect) {
// 获得CGContext，相当于画笔的角色
let paint:CGContext = UIGraphicsGetCurrentContext()!

// 设置点的位置
CGContextMoveToPoint(paint, 200, 200)
// 添加一条直线段从当前的点，指向到(x,y)
CGContextAddLineToPoint(paint, 300, 200)

CGContextMoveToPoint(paint, 250, 150)
CGContextAddLineToPoint(paint, 250, 250)

CGContextMoveToPoint(paint, 200, 150)
CGContextAddLineToPoint(paint, 300, 150)

CGContextMoveToPoint(paint, 200, 250)
CGContextAddLineToPoint(paint, 300, 250)

CGContextMoveToPoint(paint, 200, 250)
CGContextAddLineToPoint(paint, 300, 250)

CGContextMoveToPoint(paint, 280, 235)
CGContextAddLineToPoint(paint, 295, 245)

// 设置边的颜色
CGContextSetRGBStrokeColor(paint, 0.7, 0.2, 0.5, 0.6)
// 设置线条宽度
CGContextSetLineWidth(paint, 3)

// 开始绘制边的路径
CGContextStrokePath(paint)

}

}

绘制矩形

CGContext.CGContextAddRect(c: CGContext?, _ rect: CGRect)

CGContext.CGContextSetRGBFillColor(c: CGContext?, _ red: CGFloat, _ green: CGFloat, _ blue: CGFloat, _ alpha: CGFloat)

CGContext.CGContextFillPath(c: CGContext?)

CGContext.CGContextSetLineWidth(c: CGContext?, _ width: CGFloat)

CGContext.CGContextSetRGBStrokeColor(c: CGContext?, _ red: CGFloat, _ green: CGFloat, _ blue: CGFloat, _ alpha: CGFloat)

CGContext.CGContextStrokeRect(c: CGContext?, _ rect: CGRect)

class DrawRectView: UIView {

required init(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)!
}

// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
override func drawRect(rect: CGRect) {
// Drawing code
let paint:CGContext = UIGraphicsGetCurrentContext()!

// 添加矩形
CGContextAddRect(paint, CGRect(x: 100, y: 100, width: 100, height: 100))

// 设置填充颜色
CGContextSetRGBFillColor(paint, 1, 0, 0, 1)
// 开始绘制填充的路径
CGContextFillPath(paint)

// 设置线条宽度
CGContextSetLineWidth(paint, 5)
// 设置边的颜色
CGContextSetRGBStrokeColor(paint, 0, 0, 1, 1)

// 开始绘制矩形的边
CGContextStrokeRect(paint, CGRect(x: 100, y: 100, width: 100, height: 100))

}

}

绘制圆形

CGContextAddArc(c: CGContext?, _ x: CGFloat, _ y: CGFloat, _ radius: CGFloat, _ startAngle: CGFloat, _ endAngle: CGFloat, _ clockwise: Int32)

CGContextSetRGBFillColor(c: CGContext?, _ red: CGFloat, _ green: CGFloat, _ blue: CGFloat, _ alpha: CGFloat)

CGContextFillPath(c: CGContext?)

CGContextSetLineWidth(c: CGContext?, _ width: CGFloat)

CGContextStrokePath(c: CGContext?)

CGContextAddEllipseInRect(c: CGContext?, _ rect: CGRect)

CGContextStrokePath(c: CGContext?)

class DrawCircleView: UIView {

required init(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)!
}

// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
override func drawRect(rect: CGRect) {
// Drawing code
let context:CGContext = UIGraphicsGetCurrentContext()!

// 添加弧形，开始角度是0，结束角度是2*π，即圆
CGContextAddArc(context, 150, 200, 100, 0, 3.141592657*2, 0)
// 设置填充颜色
CGContextSetRGBFillColor(context, 0, 0, 1, 1)
// 开始绘制填充的路径
CGContextFillPath(context)

// 添加弧形，开始角度是0，结束角度是2*π，即圆
CGContextAddArc(context, 150, 200, 100, 0, 3.141592657*2, 0)
// 设置线的宽度
CGContextSetLineWidth(context, 10)
// 开始绘制边的路径
CGContextStrokePath(context)

// 添加椭圆
CGContextAddEllipseInRect(context, CGRect(x: 50, y: 500, width: 200, height: 100))
// 开始绘制边的路径
CGContextStrokePath(context)

}

}

绘制图像

CGContext.CGContextSaveGState(c: CGContext?)

CGContext.CGContextTranslateCTM(c: CGContext?, _ tx: CGFloat, _ ty: CGFloat)

CGContext.CGContextScaleCTM(c: CGContext?, _ sx: CGFloat, _ sy: CGFloat)

CGContext.CGContextDrawImage(c: CGContext?, _ rect: CGRect, _ image: CGImage?)

CGContext.CGContextRestoreGState(c: CGContext?)

class DrawImageView: UIView {

var uiImage:CGImageRef?

required init(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)!
self.uiImage = UIImage(named:"mz_6.jpg")?.CGImage
}

// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
override func drawRect(rect: CGRect) {
// Drawing code
let context:CGContext = UIGraphicsGetCurrentContext()!
// 保存CGContext的状态
CGContextSaveGState(context)
// 转变为当前图形状态的变换矩形
CGContextTranslateCTM(context, 10,400)
// 坐标空间转换
CGContextScaleCTM(context, 1, -1)
// 绘制图像
CGContextDrawImage(context, CGRect(x: 0, y: 0, width: 200, height: 200), self.uiImage)

// 从上一个图形堆栈中恢复当前图形状态，在这个过程里，弹出这个图形状态的堆栈
// 简单开说，开始绘图了
CGContextRestoreGState(context)

}

}

写字板

UIResponder.touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?)

UIResponder.touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?)

NSSet.anyObject() -> AnyObject?

UITouch.locationInView(view: UIView?)

CGPath.CGPathCreateMutable() -> CGMutablePath

CGPath.CGPathAddLineToPoint(path: CGMutablePath?, _ m: UnsafePointer<CGAffineTransform>, _ x: CGFloat, _ y: CGFloat)

UIView.setNeedsDisplay()

CGContext.CGContextAddPath(c: CGContext?, _ path: CGPath?)

class DrawBoardView: UIView {

// 创建一个的可变路径
var path = CGPathCreateMutable()

required init(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)!
}

// touch事件，开始
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
// 取得当前点的坐标
let p:CGPoint = (touches as NSSet).anyObject()!.locationInView(self)
// 设置点的位置
CGPathMoveToPoint(self.path, nil, p.x, p.y)
}
// touch事件，移动
override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
// 取得当前点的坐标
let p:CGPoint = (touches as NSSet).anyObject()!.locationInView(self)
// 添加线到当前路径
CGPathAddLineToPoint(self.path, nil, p.x, p.y)
// 异步执行,setNeedsDisplay会调用自动调用drawRect方法
setNeedsDisplay()
}

// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
override func drawRect(rect: CGRect) {
// Drawing code
let context:CGContext = UIGraphicsGetCurrentContext()!
// 把一个路径添加到graphics context中
CGContextAddPath(context, self.path)
CGContextSetLineWidth(context, 2.0)
CGContextStrokePath(context)
}

}