先上效果图
绘制三角形的代码如下：
1、创建画三角形所需要的类LjDrawRect，具体如下
//.h文件的代码
#import@interface LjDrawRect : UIView
- (instancetype)initStartPoint:(CGPoint)startPoint middlePoint:(CGPoint)middlePoint endPoint:(CGPoint)endPoint color:(UIColor*)color;
@end
//.m文件的代码
#import "LjDrawRect.h"
@interface LjDrawRect ()
{
CGPoint _startPoint;
CGPoint _middlePoint;
CGPoint _endPoint;
UIColor *_color;
}
@end
@implementation LjDrawRect
#pragma mark -
#pragma mark - method
- (instancetype)initStartPoint:(CGPoint)startPoint middlePoint:(CGPoint)middlePoint endPoint:(CGPoint)endPoint color:(UIColor*)color {
self = [super init];
if (self) {
_startPoint = startPoint;
_middlePoint = middlePoint;
_endPoint = endPoint;
_color = color;
self.backgroundColor = [UIColor clearColor];
}
return self;
}
- (void)drawRect:(CGRect)rect {
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextBeginPath(context);//标记
CGContextMoveToPoint(context, _startPoint.x, _startPoint.y);
CGContextAddLineToPoint(context,_middlePoint.x, _middlePoint.y);
CGContextAddLineToPoint(context,_endPoint.x, _endPoint.y);
CGContextClosePath(context);//路径结束标志，不写默认封闭
[_color setFill]; //设置填充色
[_color setStroke];//边框也设置为_color，否则为默认的黑色
CGContextDrawPath(context, kCGPathFillStroke);//绘制路径path
}
@end
2、再调用下面的方法即可
- (void)ljTestView {
CGPoint piont1;
piont1.x = 170;
piont1.y = 100;
CGPoint piont2;
piont2.x = 50;
piont2.y = 200;
CGPoint piont3;
piont3.x = 220;
piont3.y = 200;
LjDrawRect *_ljView = [[LjDrawRect alloc] initStartPoint:piont1 middlePoint:piont2 endPoint:piont3 color:[UIColor redColor]];
_ljView.frame = CGRectMake(0, 64, kDEVICEWIDTH, kDEVICEHEIGHT - 64);
_ljView.backgroundColor = [UIColor yellowColor];
[self.view addSubview:_ljView];
}
