1.前言

应公司项目要求，我们有一个打分的功能，有十分制和百分制两种，主要用到UIDynamicAnimator和UISnapBehavior。UIkit动力学是UIkit框架中模拟真实世界的一些特性。主要有UIDynamicAnimator类，通过这个类中的不同行为来实现一些动态特性。UIDynamicAnimator有五个不同的行为，UIAttachmentBehavior（吸附），UICollisionBehavior（碰撞），UIGravityBehavior（重力），UIPushBehavior（推动），UISnapBehavior（捕捉）。另外还有一个辅助的行为UIDynamicItemBehavior，用来在item层级设定一些参数，比如item的摩擦，阻力，角阻力，弹性密度和可允许的旋转等等。这里面我主要说UISnapBehavior的用法。

2.十分制

调用非常简单，我封装了一下，如下：

[ZFJScoreView showScoreView:ZFJExtraordinarySystem scorBtnAction:^(CGFloat score) { NSLog(@"你打的分数 == %f",score); _scoreLab.text = [NSString stringWithFormat:@"您打了%.0f分",score]; }]; 主要代码

我创建了十个UIButton，给他们设置一个初始frame，然后通过UISnapBehavior设置一个CGPoint点；

- (void)createMenu{ UIDynamicAnimator *animator = [[UIDynamicAnimator alloc]initWithReferenceView:self]; //#16E4B6 100% for (int i = 0; i<10; i++) { UIButton *scoreBtn = [[UIButton alloc]init]; scoreBtn.frame = CGRectMake((ScreenWidth - BtnWidth)/2, ScreenHeight - BtnWidth, BtnWidth, BtnWidth); [scoreBtn setTitle:[NSString stringWithFormat:@"%d",10-i] forState:UIControlStateNormal]; scoreBtn.titleLabel.font = [UIFont fontWithName:@"STHeitiSC-Light" size:18]; scoreBtn.backgroundColor = [self getScoreColor:i]; scoreBtn.layer.masksToBounds = YES; scoreBtn.layer.cornerRadius = BtnWidth/2; [self addSubview:scoreBtn]; [scoreBtn addTarget:self action:@selector(scoreBtnClick:) forControlEvents:UIControlEventTouchUpInside]; CGFloat pointX = KBtnSpace + BtnWidth/2 + (KBtnSpace + BtnWidth) * (i%5); CGFloat pointY = ScreenHeight/2 - BtnWidth/2 - KBtnSpace/2 + (KBtnSpace/2 + BtnWidth) * (i/5); CGPoint point = CGPointMake(pointX, pointY); UISnapBehavior *snap = [[UISnapBehavior alloc]initWithItem:scoreBtn snapToPoint:point]; [animator addBehavior:snap]; } self.animator = animator; }

3.百分制

调用和十分制是一样的；

[ZFJScoreView showScoreView:ZFJPercentileSystem scorBtnAction:^(CGFloat score) { NSLog(@"你打的分数 == %f",score); _scoreLab.text = [NSString stringWithFormat:@"您打了%.0f分",score]; }]; 百分制的实现代码

#pragma mark - 以下是百分制 //#EF5F20 100% - (void)createPercentileSystem{ UIDynamicAnimator *animator = [[UIDynamicAnimator alloc]initWithReferenceView:self]; UIView *PercentileView = [[UIButton alloc]init]; PercentileView.frame = CGRectMake((ScreenWidth - KPercentileWID)/2, (ScreenHeight - KPercentileWID), KPercentileWID, KPercentileWID); PercentileView.backgroundColor = [UIColor colorWithRed:0.937 green:0.373 blue:0.125 alpha:1.00]; PercentileView.layer.masksToBounds = YES; PercentileView.layer.cornerRadius = KPercentileWID/2; [self addSubview:PercentileView]; [PercentileView addSubview:self.ScoreTextField]; //满分100分 UILabel *showLab = [[UILabel alloc]init]; showLab.frame = CGRectMake((KPercentileWID - 115)/2, CGRectGetMaxY(self.ScoreTextField.frame) + 9, 115, 13); showLab.text = @"满分100分"; showLab.textAlignment = NSTextAlignmentCenter; showLab.font = [UIFont fontWithName:@"STHeitiSC-Light" size:13]; showLab.textColor = [UIColor whiteColor]; [PercentileView addSubview:showLab]; CGFloat pointX = (ScreenWidth - KPercentileWID)/2 + KPercentileWID/2; CGFloat pointY = (ScreenHeight - KPercentileWID)/2 + KPercentileWID/2; CGPoint point = CGPointMake(pointX, pointY); UISnapBehavior *snap = [[UISnapBehavior alloc]initWithItem:PercentileView snapToPoint:point]; snap.damping = 0.8f;//剧烈程度 [animator addBehavior:snap]; self.animator = animator; }

4.效果预览

5.DEMO下载

点击下载

http://download.csdn.net/detail/u014220518/9773882