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UIGestureRecognizer是一个界说基本手势的抽象类,具体包罗:
1、拍击UITapGestureRecognizer (任意次数的拍击)
2、向里或向外捏UIPinchGestureRecognizer (用于缩放)
3、摇动或者拖拽UIPanGestureRecognizer (拖动)
4、擦碰UISwipeGestureRecognizer (以任意偏向)
5、旋转UIRotationGestureRecognizer (手指朝相反偏向移动)
6、长按UILongPressGestureRecognizer (长按)
本文主要使用到的是拖拽手势:UIPanGestureRecognizer
限制要领:
-(void)doMoveAction:(UIPanGestureRecognizer *)recognizer{ // Figure out where the user is trying to drag the view. CGPoint translation = [recognizer translationInView:self.view]; CGPoint newCenter = CGPointMake(recognizer.view.center.x+ translation.x, recognizer.view.center.y + translation.y);// 限制屏幕范围: newCenter.y = MAX(recognizer.view.frame.size.height/2, newCenter.y); newCenter.y = MIN(self.view.frame.size.height - recognizer.view.frame.size.height/2, newCenter.y); newCenter.x = MAX(recognizer.view.frame.size.width/2, newCenter.x); newCenter.x = MIN(self.view.frame.size.width - recognizer.view.frame.size.width/2,newCenter.x); recognizer.view.center = newCenter; [recognizer setTranslation:CGPointZero inView:self.view]; }
也可以使用UITouch来实现:
当手指接触到屏幕,不管是单点触摸还是多点触摸,事件都会开始,直到用户所有的手指都离开屏幕。期间所有的UITouch工具都被包罗在UIEvent事件工具中,由法式分发给处理者。事件记录了这个周期中所有触摸工具状态的变化。
限制要领如下:
BOOL isMove; CGPoint legend_point; -(void)touchesBegan:(NSSet*)touches withEvent:(UIEvent *)event{ [super touchesBegan:touches withEvent:event]; isMove = NO; UITouch *touch = [touches anyObject]; CGPoint point = [touch locationInView:self.view]; if (CGRectContainsPoint(V2.frame, point)) { legend_point = [touch locationInView:V2]; isMove = YES; } } -(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{ [super touchesMoved:touches withEvent:event]; if (!isMove) { return; } @autoreleasepool { UITouch *touch = [touches anyObject]; CGPoint point = [touch locationInView:self.view]; //转化成相对的中心 point.x += V2.frame.size.width/2.0f - legend_point.x; point.y += V2.frame.size.height/2.0f - legend_point.y; // 限制范围 if (point.x < V2.frame.size.width / 2.0f) { point.x = V2.frame.size.width / 2.0f; } if (point.y < V2.frame.size.height / 2.0f) { point.y = V2.frame.size.height / 2.0f; } if (point.x > self.view.frame.size.width - V2.frame.size.width / 2.0f) { point.x = self.view.frame.size.width - V2.frame.size.width / 2.0f; } if (point.y > self.view.frame.size.height - V2.frame.size.height / 2.0f) { point.y = self.view.frame.size.height - V2.frame.size.height / 2.0f; } V2.center = point; } }
效果如图:
用意志战胜身体的惰性!
本文由 姬長信 创作,文章地址:https://blog.isoyu.com/archives/1454.html
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