基本图形的绘制

Posted on 2016-07-11 18:56  柠檬片  阅读(109)  评论(0)    收藏  举报 
  1 //作用:专门用绘图
  2 //什么时候调用:在View显示的时候调用
  3 //rect:当前View的bounds
  4 - (void)drawRect:(CGRect)rect {
  5     
  6     //无论有没有看到上下文.只要在View上面绘图,就必须在drawRect方法.
  7   
  8     //cornerRadius:圆角半径
  9 //    UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(50, 50, 100, 100) cornerRadius:50];
 10     
 11     //画椭圆
 12 //    UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(50, 50, 100, 100)];
 13     
 14     //ArcCenter:圆心
 15     //radius:圆的半径
 16     //startAngle:开始角度//起始点圆的最右侧.
 17     //endAngle:截至角度
 18     //clockwise:顺时针还是逆时针 YES:顺时针 NO:逆时针
 19     
 20     CGPoint center = CGPointMake(rect.size.width * 0.5, rect.size.height * 0.5);
 21     CGFloat radius = rect.size.width * 0.5 - 10;
 22     CGFloat startA = 0;
 23     CGFloat endA = -M_PI_2;
 24     
 25     UIBezierPath *path = [UIBezierPath bezierPathWithArcCenter:center radius:radius startAngle:startA endAngle:endA clockwise:NO];
 26     
 27     [path addLineToPoint:center];
 28     
 29     //封闭路径
 30 //    [path closePath];
 31     
 32     [[UIColor blueColor] set];
 33     
 34     //fill,会自动把路径给关闭
 35     [path fill];
 36 
 37 }
 38 
 39 //画矩形.
 40 - (void)drawrect{
 41 
 42     //画矩形.
 43     //1.获取上下文
 44     CGContextRef ctx = UIGraphicsGetCurrentContext();
 45     //2.描述路径
 46     UIBezierPath *path = [UIBezierPath bezierPathWithRect:CGRectMake(50, 50, 100, 100)];
 47     //3.把路径添加到上下文
 48     CGContextAddPath(ctx, path.CGPath);
 49     
 50     [[UIColor yellowColor] set];
 51     
 52     //4.把上下文的内容显示
 53     CGContextFillPath(ctx);
 54     
 55 }
 56 
 57 
 58 //添加曲线
 59 - (void)drawQuadCurve{
 60 
 61     
 62     //1.获取跟View相关联的上下文
 63     CGContextRef ctx =  UIGraphicsGetCurrentContext();
 64     //2.描述路径
 65     UIBezierPath *path = [UIBezierPath bezierPath];
 66     //2.1设置起点
 67     [path moveToPoint:CGPointMake(20, 200)];
 68     //2.2添加一条曲线到某个点.
 69     [path addQuadCurveToPoint:CGPointMake(200, 200) controlPoint:CGPointMake(100, 10)];
 70     
 71     CGContextSetLineWidth(ctx, 10);
 72     
 73     //3.把路径添加到上下文
 74     CGContextAddPath(ctx, path.CGPath);
 75     //4.把上下文的内容显示出来.
 76     CGContextStrokePath(ctx);
 77 }
 78 
 79 //画直线
 80 - (void)drawLine{
 81 
 82     // Drawing code
 83     NSLog(@"%s",__func__);
 84     NSLog(@"%@",NSStringFromCGRect(self.bounds));
 85     
 86     //1.取得一个跟View相关联的上下文.
 87     CGContextRef ctx = UIGraphicsGetCurrentContext();
 88     //2.描述路径
 89     UIBezierPath *path = [UIBezierPath bezierPath];
 90     //2.1.设置起点
 91     [path moveToPoint:CGPointMake(10, 100)];
 92     //2.1.添加一根线到某个点
 93     [path addLineToPoint:CGPointMake(200, 20)];
 94     
 95     //一个路径上面可以画多条线
 96     //    [path moveToPoint:CGPointMake(10, 150)];
 97     //    [path addLineToPoint:CGPointMake(200, 100)];
 98     
 99     //把上一条线的终点当作是下一条线的起点.
100     [path addLineToPoint:CGPointMake(150, 200)];
101     
102     
103     //设置上下文的状态
104     //设置线的宽度
105     CGContextSetLineWidth(ctx, 10);
106     //设置线的连接样式
107     CGContextSetLineJoin(ctx, kCGLineJoinBevel);
108     //设置顶角的样式
109     CGContextSetLineCap(ctx, kCGLineCapRound);
110     //设置线的颜色
111     [[UIColor greenColor] setStroke];
112     
113     
114     //3.把路径添加到上下文
115     CGContextAddPath(ctx, path.CGPath);
116     //4.把上下文的内容显示View fill stroke
117     CGContextStrokePath(ctx);
118     
119 
120 }
基本图形(线段,弧线,扇形,园,矩形...)