多彩绘版

TouchView.h

#import <UIKit/UIKit.h>
@interface TouchView : UIView
{
    NSMutableArray * _lineArray;
}
//初始化线条颜色
@property (nonatomic,retain)UIColor * pointColor;
@end

TouchView.m

#import "TouchView.h"
#define REDTAG 10
#define YELLOWTAG 11
#define ORANGETAG 12   
#define GREENTAG 13
#define PURPLETAG 14
@implementation TouchView
- (void)dealloc {
    [_lineArray release];
    _lineArray = Nil;
    [_pointColor release];
    _pointColor = Nil;
    [super dealloc];
}
- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
          
        _lineArray = [[NSMutableArray alloc]init];
          
        //初始化颜色为黑色
       _pointColor = [UIColor blackColor];
         
//删除按钮
    UIButton * del = [[UIButton alloc]initWithFrame:CGRectMake(0, 330, 250, 20)];
    [del setBackgroundColor:[UIColor brownColor]];
    [del setTitle:@"撤销" forState:UIControlStateNormal];
    [del addTarget:self action:@selector(delAction) forControlEvents:UIControlEventTouchUpInside];
    [self addSubview:del];
    [del release];
          
//颜色按钮
    UIButton * redButton = [[UIButton alloc]initWithFrame:CGRectMake(0, 350, 50, 50)];
    [redButton setBackgroundColor:[UIColor redColor]];
        redButton.tag = REDTAG;
        [redButton addTarget:self action:@selector(colorAction:) forControlEvents:UIControlEventTouchUpInside];
    [self addSubview:redButton];
    [redButton release];
      
      
    UIButton * yellowButton = [[UIButton alloc]initWithFrame:CGRectMake(50, 350, 50, 50)];
    [yellowButton setBackgroundColor:[UIColor yellowColor]];
        yellowButton.tag = YELLOWTAG;
        [yellowButton addTarget:self action:@selector(colorAction:)forControlEvents:UIControlEventTouchUpInside];
    [self addSubview:yellowButton];
    [yellowButton release];
      
      
    UIButton * orangeButton = [[UIButton alloc]initWithFrame:CGRectMake(100, 350, 50, 50)];
    [orangeButton setBackgroundColor:[UIColor orangeColor]];
        orangeButton.tag = ORANGETAG;
        [orangeButton addTarget:self action:@selector(colorAction:) forControlEvents:UIControlEventTouchUpInside];
    [self addSubview:orangeButton];
    [orangeButton release];
      
    UIButton * greenButton = [[UIButton alloc]initWithFrame:CGRectMake(150, 350, 50, 50)];
    [greenButton setBackgroundColor:[UIColor greenColor]];
        greenButton.tag = GREENTAG;
        [greenButton addTarget:self action:@selector(colorAction:) forControlEvents:UIControlEventTouchUpInside];
    [self addSubview:greenButton];
    [greenButton release];
   
          
    UIButton * purpleButton = [[UIButton alloc]initWithFrame:CGRectMake(200, 350, 50, 50)];
    [purpleButton setBackgroundColor:[UIColor purpleColor]];
        purpleButton.tag = PURPLETAG;
        [purpleButton addTarget:self action:@selector(colorAction:) forControlEvents:UIControlEventTouchUpInside];
    [self addSubview:purpleButton];
    [purpleButton release];
          
}
      
    return self;
}
//按钮点击事件
- (void)colorAction:(id)sender
{
    UIButton * button = (UIButton *)sender;
    switch (button.tag) {
        case REDTAG:
        {
            _pointColor = [UIColor redColor];
        }
            break;
              
            case YELLOWTAG:
        {
            _pointColor = [UIColor yellowColor];
        }
            break;
              
            case ORANGETAG:
        {
            _pointColor = [UIColor orangeColor];
        }
            break;
              
            case GREENTAG:
        {
            _pointColor = [UIColor greenColor];
        }
            break;
              
            case PURPLETAG:
        {
            _pointColor = [UIColor purpleColor];
        }
            break;
              
        default:
            break;
    }
}
//4个方法进入.h中点UIView,点UIResponder进入找
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
      
    UITouch * touch = [touches anyObject];//获取触摸动作
      
    CGPoint point = [touch locationInView:self];//获得初始坐标
    NSValue * value = [NSValue valueWithCGPoint:point];//结构体转换成对象;也能用于把对象转换成结构体,这是固定格式;
      
      
    NSMutableArray * points = [NSMutableArray array];//局部变量 遍历构造器不用释放
    [points addObject:value];//
      
      
    NSMutableDictionary * dic = [NSMutableDictionary dictionary];
    [dic setObject:points forKey:@"points"];
      
      
    [dic setObject:_pointColor forKey:@"color"];
      
      
    [_lineArray addObject:dic];//将字典放到数组线中
      
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch * touch = [touches anyObject];
    CGPoint ponit = [touch locationInView:self];
    NSValue * value = [NSValue valueWithCGPoint:ponit];
      
      
//    NSMutableArray * points = [_lineArray lastObject];//取出线数组里最后一个元素
//   
//    [points addObject:value];//把移动坐标放到线数组里
      
      
      
    NSMutableDictionary * dic = [_lineArray lastObject];//
    NSMutableArray * points = [dic objectForKey:@"points"];//从大字典里取出数组
    [points addObject:value];//往小数组里添加所有点
      
      
    [self setNeedsDisplay];//调用下面画图方法;系统不允许用drawRect,用setNeedsDisplay手动调用
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
      
}
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
{
      
}
//删除事件
- (void)delAction
{
    [_lineArray removeLastObject];//移除最后一划
    [self setNeedsDisplay];
}
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
    // Drawing code
      
      
    CGContextRef context = UIGraphicsGetCurrentContext();
      
      
    for (NSDictionary * lineDic in _lineArray) {
          
          
        NSArray * line = [lineDic objectForKey:@"points"];
          
          
        NSValue * firstValue = [line firstObject];//得到起始点
        CGPoint firstPoint = [firstValue CGPointValue];//转换为Point类型;正常数据转换
          
        UIColor * color = [lineDic objectForKey:@"color"];
        CGContextSetStrokeColorWithColor(context, color.CGColor);
          
        CGContextMoveToPoint(context, firstPoint.x, firstPoint.y);//起始点
          
          
        for (NSValue * value in [lineDic objectForKey:@"points"]) {
            CGPoint currentPonit = [value CGPointValue];
            CGContextAddLineToPoint(context, currentPonit.x, currentPonit.y);
        }
          
        CGContextStrokePath(context);
   
    }
}
@end