objectivec-如何指定只在特定图像上进行触摸

Question

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
 UITouch * t =[touches anyobject];
CGpoint * point = [t locationinview:self.view];
If([t view]) == imageview {
Imageview.center = point;
}
}

Answer 1

检查图像矩形内的点：

if (CGRectContainsPoint(imageview.bounds, point)) {
    //point inside imageView frame
}

您也可以在该图像视图上设置手势识别器，所需的方法将被称为仅用户触摸该特定图像，例如：

-(void)viewDidLoad {
    [super viewDidLoad];
    UITapGestureRecognizer *gr = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(imageTouched:)];
    gr.numberOfTapsRequired = 1;
    gr.numberOfTouchesRequired = 1;
    [imageview addGestureRecognizer:gr];
}
-(void)imageTouched:(UITapGestureRecognizer*)recognizer{
    //image view touched
}