３回画面をタッチすると、タッチした点を結んだ三角形が表示されるといった簡単なiPhoneアプリのサンプルコードを描いてみます。
サンプルを動かした動画です
サンプルコード
#import “ViewController.h”
@interface ViewController ()
@property (strong, nonatomic) NSMutableArray *points;
@property (strong, nonatomic) NSMutableArray *marks;
@end
@implementation ViewController
– (void)viewDidLoad
{
[super viewDidLoad];
self.view.backgroundColor = [self color:0];
}
– (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
if (!self.points) self.points = [[NSMutableArray alloc] init];
if (!self.marks) self.marks = [[NSMutableArray alloc] init];
for (UITouch *t in touches) {
[self.points addObjectsFromArray:[touches allObjects]];
CGPoint p = [t locationInView:self.view];
UILabel *markLabel = [[UILabel alloc] init];
NSMutableAttributedString *mstr = [[NSMutableAttributedString alloc] initWithString:@”x”];
[mstr addAttributes:@{
NSFontAttributeName : [UIFont preferredFontForTextStyle:UIFontTextStyleHeadline],
NSStrokeWidthAttributeName : @-4,
NSStrokeColorAttributeName : [self color:0],
NSForegroundColorAttributeName : [self color:2]
} range:NSMakeRange(0, 1)];
markLabel.attributedText = mstr;
[markLabel sizeToFit];
markLabel.center = p;
[self.view addSubview:markLabel];
markLabel.transform = CGAffineTransformMakeScale(5.0, 5.0);
[UIView animateWithDuration:0.5 animations:^{
markLabel.transform = CGAffineTransformIdentity;
}];
}
}
– (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
if ([self.points count] > 2) {
[self createTraiangle:[((UITouch *) self.points[0]) locationInView:self.view]
point2:[((UITouch *) self.points[1]) locationInView:self.view]
point3:[((UITouch *) self.points[2]) locationInView:self.view]];
[self.points removeAllObjects];
}
}
– (void)createTraiangle:(CGPoint)p1 point2:(CGPoint)p2 point3:(CGPoint)p3
{
UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:p1];
[path addLineToPoint:p2];
[path addLineToPoint:p3];
CAShapeLayer *sl = [CAShapeLayer layer];
sl.path = path.CGPath;
sl.fillColor = [self color:arc4random()%4 + 1].CGColor;
[self.view.layer addSublayer:sl];
}
#define UIColorHex(rgbValue) [UIColor colorWithRed:((float)((rgbValue & 0xFF0000) >> 16))/255.0 green:((float)((rgbValue & 0xFF00) >> 8))/255.0 blue:((float)(rgbValue & 0xFF))/255.0 alpha:0.8]
– (UIColor*)color:(int)i
{
switch (i) {
case 0:
return UIColorHex(0x1D2939);
case 1:
return UIColorHex(0x1CAF9A);
case 2:
return UIColorHex(0xFEFEFE);
case 3:
return UIColorHex(0xEE4F4B);
case 4:
return UIColorHex(0xD1DC48);
default:
break;
}
return nil;
}
– (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end