我在 View 中有一个 UIBezierPath 。我想在单击形状时显示警报,但实际发生的情况是,不仅在我单击形状时显示警报,而且当我单击 View 中的任意位置时也会显示警报。
如何更改此代码,以便仅当我在彩色形状内单击时才会收到警报?
另外,如何使形状在屏幕上可拖动?
#import "draw2D.h"
@implementation draw2D
- (id)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
// Initialization code.
}
return self;
}
- (void)drawRect:(CGRect)rect {
UIBezierPath* aPath = [UIBezierPath bezierPath];
[aPath moveToPoint:CGPointMake(200.053,79.688)];
[aPath addLineToPoint:CGPointMake(100.053,179.688)];
[aPath addLineToPoint:CGPointMake(304.412,280.125)];
[aPath addLineToPoint:CGPointMake(308.055,298.513)];
[aPath addLineToPoint:CGPointMake(200.053,79.688)];
[aPath closePath];
[[UIColor blackColor] setStroke];
[[UIColor redColor] setFill];
CGContextRef aRef = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(aRef, 50, 50);
aPath.lineWidth = 5;
[aPath fill];
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Title" message:@"Some message" delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles: nil];
//After some time
[alert show];
[alert release];
}
- (void)dealloc {
[super dealloc];
}
@end
最佳答案
最好的方法是对贝塞尔路径进行 HitTest 。这需要访问 drawRect: 方法之外的路径。由于您的路径始终相同,因此您可以使用静态变量轻松完成此操作。
//add this method to your class
- (UIBezierPath *)myPath {
static UIBezierPath *path = nil;
if(!path) {
path = [[UIBezierPath bezierPath] retain];
[path moveToPoint:CGPoingMake(200.053,79.688)];
[path addLineToPoint:CGPointMake(100.053,179.688)];
[path addLineToPoint:CGPointMake(304.412,280.125)];
[path addLineToPoint:CGPointMake(308.055,298.513)];
[path addLineToPoint:CGPointMake(200.053,79.688)];
[path closePath];
path.lineWidth = 5;
}
return path;
}
- (void)drawRect:(CGRect)rect {
UIBezierPath* aPath = [self myPath];
[[UIColor blackColor] setStroke];
[[UIColor redColor] setFill];
CGContextRef aRef = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(aRef, 50, 50);
[aPath fill];
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
if(![[self myPath] containsPoint:[[touches anyObject] locationInView:self]]) return;
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Title" message:@"Some message" delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles: nil];
//After some time
[alert show];
[alert release];
}
编辑 对于仅响应路径内事件的自定义 View 。
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event {
return [[self myPath] containsPoint:point];
}
使用这种方法,您不需要检查触摸是否在 touchesBegan 的路径内,因为您不应该得到任何会导致测试失败的事件。您可以通过将其框架原点更改为与触摸移动相同的量来移动 View 。
关于iphone - UIBezierPath 路径形状可点击和可拖动,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/4950749/