开发绘图、手势综合App注意点

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

源码地址：https://github.com/fantasticlbp/blogdemos/tree/master/

以上就是本次我们分享的全部内容，感谢你对的支持。