绘画板

知识点：将View上的信息保存到相册

关于绘制图形、路线



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#import <UIKit/UIKit.h>

@interface FFFPaintView : UIView

@property (nonatomic,strong) UIColor *lineColor;

@property(nonatomic,assign) CGFloat lineWithed;

@property (nonatomic,copy) CGFloat (^lineWithBlock)();

//清屏

-(void)clearScreen;

//回退

-(void)recede;

//橡皮擦

-(void)eraser;

@end

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#import "FFFPaintView.h"

@interface FFFBezierPath : UIBezierPath

@property (nonatomic,strong) UIColor *lineColor;

@end

@implementation FFFBezierPath

@end

@interface FFFPaintView ()

@property (nonatomic,strong) NSMutableArray *paths;

@end

@implementation FFFPaintView

-(NSMutableArray *)paths{

if(_paths==nil){

_paths = [NSMutableArray array];

}

return _paths;

}

//清屏

-(void)clearScreen{

// 注意这里有时候移除全部的时候会出错，所以为了防止，建议 == nil,即可，然后在重绘

[self.paths removeAllObjects];

self.paths = nil;

// 重绘

[self setNeedsDisplay];

}

//回退

-(void)recede{

[self.paths removeLastObject];

// 重绘

[self setNeedsDisplay];

}

//橡皮擦

-(void)eraser{

self.lineColor = self.backgroundColor;

// 重绘

[self setNeedsDisplay];

}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{

// 获取触摸的对象

UITouch *touch = [touches anyObject];

// 通过触摸对象获取手指的位置

CGPoint point = [touch locationInView:touch.view];

// 创建路径对象

FFFBezierPath *path = [[FFFBezierPath alloc] init];

[path moveToPoint:point];

// 设置线的颜色

path.lineColor = self.lineColor;

if(self.lineWithBlock){

path.lineWidth = self.lineWithBlock();

}

// 下面的方法是无法获取到值的

// path.lineWidth = self.lineWithed;

// NSLog(@"%f",self.lineWithed);

// 把path添加到数组中

[self.paths addObject:path];

}

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

// 获取触摸的对象

UITouch *touch = [touches anyObject];

CGPoint point = [touch locationInView:touch.view];

// 使用数组当中最后一个路径 来连线

[[self.paths lastObject] addLineToPoint:point];

// 重绘

[self setNeedsDisplay];

}

-(void)drawRect:(CGRect)rect{

// 遍历所有的路径渲染

for (FFFBezierPath *path in self.paths) {

[path.lineColor set];

// 设置样式

[path setLineCapStyle:kCGLineCapRound];

[path setLineJoinStyle:kCGLineJoinRound];

// 渲染

[path stroke];

// NSLog(@"%@",path);

}

}

@end

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#import "ViewController.h"

#import "FFFPaintView.h"

@interface ViewController ()

@property (weak, nonatomic) IBOutlet FFFPaintView *paintView;

@property (weak, nonatomic) IBOutlet UISlider *slider;

@property (weak, nonatomic) IBOutlet UIButton *firstButton;

@end

@implementation ViewController

//- (IBAction)slider:(UISlider *)sender {

//

// self.paintView.lineWithed = sender.value;

//

//}

- (IBAction)savePaint {

// 开启图片类型的上下文

UIGraphicsBeginImageContextWithOptions(self.paintView.bounds.size, NO, 0);

// 获取当前上下文

CGContextRef ctx = UIGraphicsGetCurrentContext();

// 把当前view的样式，绘制到上下文当中

[self.paintView.layer renderInContext:ctx];

// 保存到相册，同时从上下文中获取图片

UIImageWriteToSavedPhotosAlbum(UIGraphicsGetImageFromCurrentImageContext(), nil, nil, nil);

// 关闭上下文

UIGraphicsEndImageContext();

}

//清屏

-(IBAction)clearScreen{

[self.paintView clearScreen];

}

//回退

-(IBAction)recede{

[self.paintView recede];

}

//橡皮擦

-(IBAction)eraser{

[self.paintView eraser];

}

- (void)viewDidLoad {

[super viewDidLoad];

[self.paintView setLineWithBlock:^CGFloat{

return self.slider.value;

}];

self.paintView.lineColor = self.firstButton.backgroundColor;

}

- (IBAction)setColorSelected:(UIButton *)sender {

self.paintView.lineColor = sender.backgroundColor;

}

@end

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