iOS Core Graphics封裝虛線

HJDashLineView.h

//
//  HJDashLineView.h
//  CGContextDemo
//
//  Created by 黃健 on 16/7/18.
//  Copyright © 2016年 黃健. All rights reserved.
//

#import <UIKit/UIKit.h>

typedef enum : NSUInteger {
    HJLineTypeDashLine,
    HJLineTypeStraightLine
} HJLineType;

IB_DESIGNABLE

@interface HJDashLineView : UIView

// 如果不指定 lineType，默認繪製虛線，否則爲實線
@property (nonatomic, assign) IBInspectable BOOL lineType;

/**
 線條寬度 lineWidth 默認 1
 線條顏色 lineColor 默認 blackColor
 偏移點數 movePoint 默認 0
 繪製點數 drawPoint 默認 5
 跳過點數 stepPoint 默認 3

 當視圖寬大於高，水平虛線
 當視圖高大於寬，豎直虛線
 當視圖寬高相等，豎直虛線
 */
@property (nonatomic, assign) IBInspectable CGFloat  lineWidth;
@property (nonatomic, strong) IBInspectable UIColor *lineColor;
@property (nonatomic, assign) IBInspectable CGFloat  movePoint;
@property (nonatomic, assign) IBInspectable CGFloat  drawPoint;
@property (nonatomic, assign) IBInspectable CGFloat  stepPoint;

@end

HJDashLineView.m

//
//  HJDashLineView.m
//  CGContextDemo
//
//  Created by 黃健 on 16/7/18.
//  Copyright © 2016年 黃健. All rights reserved.
//

#import "HJDashLineView.h"

@implementation HJDashLineView

- (void)layoutSubviews
{
    [super layoutSubviews];

    // 由於設置的是直線或虛線，直接設置背景顏色爲透明
    self.backgroundColor = [UIColor clearColor];
}

- (instancetype)initWithFrame:(CGRect)frame
{
    if (self = [super initWithFrame:frame]) {

    }
    return self;
}

- (instancetype)initWithCoder:(NSCoder *)aDecoder
{
    if (self = [super initWithCoder:aDecoder]) {

    }
    return self;
}

-(void)drawRect:(CGRect)rect
{
    CGContextRef context  = UIGraphicsGetCurrentContext();
    CGMutablePathRef path = CGPathCreateMutable();

    CGFloat width  = self.bounds.size.width;
    CGFloat height = self.bounds.size.height;

    if (width > height)
    {
        CGPathMoveToPoint(path, nil, 0, height / 2.f);
        CGPathAddLineToPoint(path, nil, width, height / 2.f);
    }
    else
    {
        CGPathMoveToPoint(path, nil, width / 2.f, 0);
        CGPathAddLineToPoint(path, nil, width / 2.f, height);
    }

    CGContextAddPath(context, path);

    CGContextSetStrokeColorWithColor(context, self.lineColor ? self.lineColor.CGColor : [UIColor blackColor].CGColor);
    CGContextSetLineWidth(context, self.lineWidth == 0 ? 1 : self.lineWidth);

    if (self.lineType == HJLineTypeDashLine)
    {
        CGFloat lengths[2] = {self.drawPoint == 0 ? 5 : self.drawPoint, self.stepPoint == 0 ? 3 : self.stepPoint};
        CGContextSetLineDash(context, self.movePoint == 0 ? 0 : -self.movePoint, lengths, 2);
    }

    CGContextDrawPath(context, kCGPathFillStroke);
}

- (void)setLineType:(BOOL)lineType
{
    _lineType = lineType;
    [self setNeedsDisplay];
}

- (void)setLineWidth:(CGFloat)lineWidth
{
    _lineWidth = lineWidth;
    [self setNeedsDisplay];
}

- (void)setLineColor:(UIColor *)lineColor
{
    _lineColor = lineColor;
    [self setNeedsDisplay];
}

- (void)setMovePoint:(CGFloat)movePoint
{
    _movePoint = movePoint;
    [self setNeedsDisplay];
}

- (void)setDrawPoint:(CGFloat)drawPoint
{
    _drawPoint = drawPoint;
    [self setNeedsDisplay];
}

- (void)setStepPoint:(CGFloat)stepPoint
{
    _stepPoint = stepPoint;
    [self setNeedsDisplay];
}

@end

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