IOS 绘制三角形的实例详解

ios 绘制三角形的实例详解

先上效果图

上面三角形的代码

- (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]; 
} 

画三角形的类

#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 

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