iOS粒子路径移动效果 iOS实现QQ拖动效果

//获取两个圆之间的距离CGFloat distance = [self distanceWithSmallCircle:self.smallCircle bigCircle:self];if(distance<=MAX_DIST){//只有距离不超过最大距离才计算小圆半径 //计算小圆的半径 //小圆半径最小的时候是MIN_RADIUS,这个时候两个圆达到最大距离MAX_DIST //小圆半径最大的时候是原始半径，这个时候两圆距离是0 //处于前面两者之间的时候，小圆的半径是：MIN_RADIUS + (原始半径 - MIN_RADIUS)/MAX_DIST * （MAX_DIST - 当前的距离） CGFloat smallR = self.bounds.size.width * 0.5; smallR = MIN_RADIUS + (MAX_DIST-distance) * (smallR-MIN_RADIUS)/MAX_DIST; //重新设置小圆的尺寸 self.smallCircle.bounds = CGRectMake(0, 0, smallR*2, smallR*2); //重新设置小圆的半径 self.smallCircle.layer.cornerRadius = smallR;}else{//超过了最大距离 self.smallCircle.hidden = YES;}

//// BageValueView.m// 03_UIView78_粒子效果2//// Created by 杞文明 on 17/7/22.// Copyright © 2017年 杞文明. All rights reserved.//#import "BageValueView.h"#define MAX_DIST 80#define MIN_RADIUS 5@interface BageValueView()@property (nonatomic, weak) UIView *smallCircle;@property (nonatomic, weak) CAShapeLayer *shap;@end@implementation BageValueView-(void)awakeFromNib{ [self setUp];}-(instancetype)initWithFrame:(CGRect)frame{ if ( self = [super initWithFrame:frame] ) {  [self setUp]; } return self;}//形状图层-(CAShapeLayer*)shap{ if(_shap == nil){  //形状图层，它可以根据一个路径生成一个形状  CAShapeLayer *shap = [CAShapeLayer layer];  //设置形状填充色  shap.fillColor = [UIColor redColor].CGColor;  _shap = shap;  //添加到最底层  [self.superview.layer insertSublayer:shap atIndex:0]; } return _shap;}//初始化-(void)setUp{ //设置圆角 self.layer.cornerRadius = self.bounds.size.width * 0.5; //设置背景文字颜色 [self setBackgroundColor:[UIColor redColor]]; [self setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal]; self.titleLabel.font = [UIFont systemFontOfSize:12]; //添加手势 UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(pan:)]; [self addGestureRecognizer:pan]; //添加小圆 UIView *smallCircle = [[UIView alloc]initWithFrame:self.frame]; smallCircle.backgroundColor = self.backgroundColor; smallCircle.layer.cornerRadius = self.layer.cornerRadius; self.smallCircle = smallCircle; //把小圆添加到父控件中，并且在大圆下面 [self.superview insertSubview:smallCircle belowSubview:self];}-(void)pan:(UIPanGestureRecognizer*)pan{ //获取当前点 CGPoint currentP = [pan translationInView:self]; //移动 CGPoint center = self.center; center.x += currentP.x; center.y += currentP.y; self.center = center; //复位 [pan setTranslation:CGPointZero inView:self]; //获取两个圆之间的距离 CGFloat distance = [self distanceWithSmallCircle:self.smallCircle bigCircle:self]; if(distance<=MAX_DIST){//只有距离不超过最大距离才计算小圆半径  //计算小圆的半径  //小圆半径最小的时候是MIN_RADIUS,这个时候两个圆达到最大距离MAX_DIST  //小圆半径最大的时候是原始半径，这个时候两圆距离是0  //处于前面两者之间的时候，小圆的半径是：MIN_RADIUS + (原始半径 - MIN_RADIUS)/MAX_DIST * （MAX_DIST - 当前的距离）  CGFloat smallR = self.bounds.size.width * 0.5;  smallR = MIN_RADIUS + (MAX_DIST-distance) * (smallR-MIN_RADIUS)/MAX_DIST;  //重新设置小圆的尺寸  self.smallCircle.bounds = CGRectMake(0, 0, smallR*2, smallR*2);  //重新设置小圆的半径  self.smallCircle.layer.cornerRadius = smallR; }else{//超过了最大距离  self.smallCircle.hidden = YES;  [self.shap removeFromSuperlayer]; } //创建不规则路径，其实就是连个圆之间连接的部分 //小圆不隐藏才创建 if(self.smallCircle.hidden == NO){  UIBezierPath *path = [self pathWithSmallCircle:self.smallCircle bigCircle:self];  self.shap.path = path.CGPath; } //当手指松开的时候 if (pan.state==UIGestureRecognizerStateEnded) {  //如果两圆之间的距离小于最大距离，大圆复位  if (distance<MAX_DIST) {   //移除形状图层   [self.shap removeFromSuperlayer];   //添加一个弹性动画   [UIView animateWithDuration:0.25 delay:0 usingSpringWithDamping:0.2 initialSpringVelocity:0 options:UIViewAnimationOptionCurveLinear animations:^{    //大圆复位    self.center = self.smallCircle.center;   } completion:^(BOOL finished) {    //小圆显示    self.smallCircle.hidden = NO;   }];  } else {   //距离大于最大位置的时候，播放动画，按钮从父控件中删除   //添加一个UIImageView 用来播放动画   UIImageView *imageV = [[UIImageView alloc] initWithFrame:self.bounds];   [self addSubview:imageV];   //添加图片   NSMutableArray *imageArray = [NSMutableArray array];   for (int i=1; i<=8; i++) {    NSString *imageName = [NSString stringWithFormat:@"%d",i];    UIImage *image = [UIImage imageNamed:imageName];    [imageArray addObject:image];   }   imageV.animationImages = imageArray;   //设置动画时长   [imageV setAnimationDuration:1];   //开始动画   [imageV startAnimating];   //一秒钟后.把当前的按钮从父控件当中移.   dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{    [self removeFromSuperview];   });  } }}//计算两个圆之间的距离 使用勾股定理：两直角边的平方和等于斜边的平方- (CGFloat)distanceWithSmallCircle:(UIView *)smallCircle bigCircle:(UIView *)bigCircle{ //X轴上的偏移量（就是x1-x2的值） CGFloat offsetX = bigCircle.center.x - smallCircle.center.x; //y轴上的偏移量（就是y1-y2的值） CGFloat offsetY = bigCircle.center.y - smallCircle.center.y; return sqrt(offsetX*offsetX + offsetY*offsetY);}//根据两个圆设置一个不规的路径- (UIBezierPath *)pathWithSmallCircle:(UIView *)smallCircle bigCircle:(UIView *)bigCircle{ CGFloat x1 = smallCircle.center.x; CGFloat y1 = smallCircle.center.y; CGFloat x2 = bigCircle.center.x; CGFloat y2 = bigCircle.center.y; CGFloat d = [self distanceWithSmallCircle:smallCircle bigCircle:self]; if (d <= 0) {  return nil; } CGFloat cosθ = (y2 - y1) / d; CGFloat sinθ = (x2 - x1) / d; CGFloat r1 = smallCircle.bounds.size.width * 0.5; CGFloat r2 = bigCircle.bounds.size.width * 0.5; CGPoint pointA = CGPointMake(x1 - r1 * cosθ, y1 + r1 * sinθ); CGPoint pointB = CGPointMake(x1 + r1 * cosθ, y1 - r1 * sinθ); CGPoint pointC = CGPointMake(x2 + r2 * cosθ, y2 - r2 * sinθ); CGPoint pointD = CGPointMake(x2 - r2 * cosθ, y2 + r2 * sinθ); CGPoint pointO = CGPointMake(pointA.x + d * 0.5 * sinθ, pointA.y + d * 0.5 * cosθ); CGPoint pointP = CGPointMake(pointB.x + d * 0.5 * sinθ, pointB.y + d * 0.5 * cosθ); UIBezierPath *path = [UIBezierPath bezierPath]; //AB [path moveToPoint:pointA]; [path addLineToPoint:pointB]; //BC(曲线) [path addQuadCurveToPoint:pointC controlPoint:pointP]; //CD [path addLineToPoint:pointD]; //DA(曲线) [path addQuadCurveToPoint:pointA controlPoint:pointO]; return path;}//清空高亮状态-(void)setHighlighted:(BOOL)highlighted{}@end

//// ViewController.m// 03_UIView78_粒子效果2//// Created by 杞文明 on 17/7/22.// Copyright © 2017年 杞文明. All rights reserved.//#import "ViewController.h"@interface ViewController ()@end@implementation ViewController- (void)viewDidLoad { [super viewDidLoad]; //让View在显示时不要把Autoresizing转成自动布局 self.view.translatesAutoresizingMaskIntoConstraints = NO;}@end