iOS实现白板、画板功能，有趣的涂鸦工具，已封装，简单快捷使用

一、效果图：





二、选择颜色：

分【固定颜色模式】和【自由取模式】。





三、操作栏功能：





1、撤销：撤销上一步操作，可一直往上进行，直到全部清空。

2、清空：直接清除所有绘画。

3、橡皮擦：去除不要的绘画部分。

4、保存：一键保存相册。

四、实现方式：

贝塞尔曲线结合drawrect绘画。

代码结构：



核心代码模块：

#pragma mark - 画画
-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint currentPoint = [touch locationInView:self];
self.bezierPath = [[YJBezierPath alloc] init];
self.bezierPath.lineColor = self.lineColor;
self.bezierPath.isErase = self.isErase;
[self.bezierPath moveToPoint:currentPoint];

[self.beziPathArrM addObject:self.bezierPath];

}

-(void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{

UITouch *touch = [touches anyObject];
CGPoint currentPoint = [touch locationInView:self];

CGPoint previousPoint = [touch previousLocationInView:self];
CGPoint midP = midpoint(previousPoint,currentPoint);
//  这样写不会有尖头
[self.bezierPath addQuadCurveToPoint:currentPoint controlPoint:midP];
[self setNeedsDisplay];

}

-(void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
UITouch *touch = [touches anyObject];
CGPoint currentPoint = [touch locationInView:self];
CGPoint previousPoint = [touch previousLocationInView:self];
CGPoint midP = midpoint(previousPoint,currentPoint);
[self.bezierPath addQuadCurveToPoint:currentPoint   controlPoint:midP];
// touchesMoved
[self setNeedsDisplay];

}

-(void)drawRect:(CGRect)rect{
if (self.beziPathArrM.count) {
for (YJBezierPath *path in self.beziPathArrM) {
if (path.isErase) {
[self.backgroundColor setStroke];
}else{
[path.lineColor setStroke];
}

path.lineCapStyle = kCGLineCapRound;
path.lineJoinStyle = kCGLineCapRound;
if (path.isErase) {
path.lineWidth = 10;    //   这里可抽取出来枚举定义
[path strokeWithBlendMode:kCGBlendModeDestinationIn alpha:1.0];
}else{
path.lineWidth = 3;
[path strokeWithBlendMode:kCGBlendModeNormal alpha:1.0];
}
[path stroke];
}
}

[super drawRect:rect];
}

外部引用代码：

#import "BaiBanViewController.h"
#import "BaibanView.h"

@interface BaiBanViewController ()
@property (nonatomic,strong) BaibanView  *baibanV;

@end

@implementation BaiBanViewController

-(BaibanView *)baibanV{
if(_baibanV==nil){
_baibanV=[[BaibanView alloc] initWithFrame:CGRectMake(0, 64, KScreenWidth, KScreenHeight - 64)];
}
return  _baibanV;
}

- (void)viewDidLoad {
[super viewDidLoad];
self.navigationItem.title = @"画 板";
[[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -60) forBarMetrics:UIBarMetricsDefault];
self.view.backgroundColor = [UIColor whiteColor];

//添加画板功能
[self.view addSubview:self.baibanV];

}

简单吧～

五、源码获取：

我直接把我的测试Demo放上去了，大家下载后，直接定位画板功能即可。

《点击这里获取全部源码》