开发绘图、手势综合App注意点
时间：2021-03-20 10:01:51|栏目：iOS代码|点击： 次
手势的一些注意事项
对于 UITapGestureRecognizer 来说我们一般需要知道该点击手势在屏幕中的位置 （locationInView:self）
对于 UIPanGestureRecognizer 来说我们一般需要知道我们的滑动手势移动了多少距离 （translationInView:pan）
-(void) pan: (UIPanGestureRecognizer * ) pan {
CGPoint transP = [pan translationInView: pan.view]; //$1 = (x = 0.73990527317289434, y = 0)
CGPoint pont1 = [pan locationInView: self]; //$2 = (x = 198.16665649414063, y = 342.33332824707031)
CGPoint pont2 = [pan locationInView: self.imageV]; //$3 = (x = 198.12057060663793, y = 342.61609831987914)
pan.view.transform = CGAffineTransformTranslate(pan.view.transform, transP.x, transP.y);
//复位
[pan setTranslation: CGPointZero inView: pan.view];
}
[UIView animateWithDuration: 0.25 animations: ^ {
self.imageView.alpha = 0;
}completion: ^ (BOOL finished){
self.imageView.alpha = 1;
UIGraphicsBeginImageContextWithOptions(self.bounds.size, NO, 0);
CGContextRef ctx = UIGraphicsGetCurrentContext();
[self.layer renderInContext: ctx];
UIImage * imageGot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
[self.imageView removeFromSuperview];
if (self.delegate && [self.delegate respondsToSelector: @selector(handleImageView: didOperatedImage: )]){
[self.delegate handleImageView: self didOperatedImage: imageGot];
}
}
];
接下来来一个iOS图形绘制、旋转、长按、缩放、滑动等综合手势的一个 画图 项目
