UILabel混合顯示動畫效果git
效果github
源碼dom
https://github.com/YouXianMing/Animations動畫
// // MixedColorProgressViewController.m // Animations // // Created by YouXianMing on 16/1/5. // Copyright © 2016年 YouXianMing. All rights reserved. // #import "MixedColorProgressViewController.h" #import "UIView+SetRect.h" #import "GCD.h" @interface MixedColorProgressViewController () @property (nonatomic, strong) UIView *upView; @property (nonatomic, strong) UILabel *upLabel; @property (nonatomic, strong) UIView *downView; @property (nonatomic, strong) UILabel *downLabel; @property (nonatomic, strong) GCDTimer *timer; @end @implementation MixedColorProgressViewController - (void)setup { [super setup]; /* 給upView的frame值作動畫纔是label可以混色顯示的核心 upView(紅色背景) ===> upLabel(白色底字) | | | | | | | | downView(白色背景) ===> downLabel(紅色底字) */ // 上面一層 { // 紅色背景 _upView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 220, 17)]; _upView.center = self.view.center; _upView.layer.cornerRadius = 2.f; _upView.backgroundColor = [UIColor redColor]; _upView.layer.masksToBounds = YES; // 核心(不讓subview顯示超出範圍) [self.view addSubview:_upView]; // 白色底字 _upLabel = [[UILabel alloc] initWithFrame:_upView.bounds]; _upLabel.font = [UIFont fontWithName:@"HelveticaNeue-Thin" size:13]; _upLabel.text = @"YouXianMing - iOS Programmer"; _upLabel.textColor = [UIColor whiteColor]; _upLabel.textAlignment = NSTextAlignmentCenter; [_upView addSubview:_upLabel]; } // 下面一層 { // 白色背景 _downView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 220, 17)]; _downView.center = self.view.center; _downView.layer.cornerRadius = 2.f; _downView.backgroundColor = [UIColor whiteColor]; [self.view addSubview:_downView]; // 紅色底字 _downLabel = [[UILabel alloc] initWithFrame:_downView.bounds]; _downLabel.textColor = [UIColor redColor]; _downLabel.font = [UIFont fontWithName:@"HelveticaNeue-Thin" size:13]; _downLabel.text = @"YouXianMing - iOS Programmer"; _downLabel.textAlignment = NSTextAlignmentCenter; [_downView addSubview:_downLabel]; } // 顯示上面一層 [self.view bringSubviewToFront:_upView]; // 給上面一層的frame值作動畫 _timer = [[GCDTimer alloc] initInQueue:[GCDQueue mainQueue]]; [_timer event:^{ [UIView animateWithDuration:0.5f delay:0.f usingSpringWithDamping:3.f initialSpringVelocity:0 options:0 animations:^{ _upView.width = arc4random() % 220; } completion:nil]; } timeInterval:NSEC_PER_SEC]; [_timer start]; } @end
細節atom