具有动画变化效果的数字处理

约定不等于承诺〃 2022-04-16 07:15 231阅读 0赞

实现效果  
![在这里插入图片描述][20181119112806200.gif]

代码实现  
1、定义类，继承UILabel

#import <UIKit/UIKit.h>
    
    @interface AnimationLabel : UILabel
    
    @property (nonatomic, assign) NSTimeInterval duration;
    
    /**
     动画数字改变
     
     @param fromValue 开始数值
     @param toValue 结束数值
     @param duration 动画时间
     @param complete 完成回调
     */
    - (void)animationTextStartValue:(CGFloat)fromValue endValue:(CGFloat)toValue duration:(CGFloat)duration complete:(void (^)(UILabel *label, CGFloat value))complete;
    
    @end

#import "AnimationLabel.h"
    
    @interface AnimationLabel ()
    
    @property (nonatomic, strong) CADisplayLink *playLink;
    @property (nonatomic, assign) NSInteger displayPerSecond;
    
    @property (nonatomic, assign) CGFloat valueStart;
    @property (nonatomic, assign) CGFloat valueEnd;
    
    @property (nonatomic, assign) CGFloat valueLast;
    @property (nonatomic, assign) CGFloat valueStep;
    
    @property (nonatomic, copy) void (^complete)(UILabel *label, CGFloat value);
    
    @end
    
    @implementation AnimationLabel
    
    #pragma mark - 方法
    
    /**
     动画数字改变
     
     @param fromValue 开始数值
     @param toValue 结束数值
     @param duration 动画时间
     @param complete 完成回调
     */
    - (void)animationTextStartValue:(CGFloat)fromValue endValue:(CGFloat)toValue duration:(CGFloat)duration complete:(void (^)(UILabel *label, CGFloat value))complete
    {
        self.duration = duration;
        if (self.duration <= 0.0) {
            self.duration = 2.0;
        }
        self.displayPerSecond = 30;
        self.valueStart = fromValue;
        self.valueEnd = toValue;
        self.complete = [complete copy];
        
        self.valueLast = self.valueStart;
        self.valueStep = (self.valueEnd - self.valueStart)/(self.duration==0?1:(self.displayPerSecond*self.duration));
        
        if (self.playLink) {
            [self.playLink invalidate];
            self.playLink = nil;
        }
        self.playLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(countingAction)];
        if (@available(iOS 10.0, *)) {
            self.playLink.preferredFramesPerSecond = self.displayPerSecond;
        } else {
            // Fallback on earlier versions
            self.playLink.frameInterval = self.displayPerSecond;
        }
        [self.playLink addToRunLoop:[NSRunLoop mainRunLoop] forMode:NSDefaultRunLoopMode];
        [self.playLink addToRunLoop:[NSRunLoop mainRunLoop] forMode:UITrackingRunLoopMode];
    }
    
    - (void)countingAction {
        self.valueLast += self.valueStep;
        
        if (self.valueStart < self.valueEnd) {
            if (self.valueLast >= self.valueEnd) {
                [self stopDisplayLink];
            }
        } else {
            if (self.valueLast <= self.valueEnd) {
                [self stopDisplayLink];
            }
        }
        
        dispatch_async(dispatch_get_main_queue(), ^{
            if (self.complete) {
                self.complete(self, self.valueLast);
            }
        });
    }
    
    - (void)stopDisplayLink
    {
        if (self.playLink) {
            [self.playLink invalidate];
            self.playLink = nil;
        }
        self.valueLast = self.valueEnd;
    }
    
    @end

2、使用

#import "AnimationLabel.h"

self.label = [[AnimationLabel alloc] initWithFrame:CGRectMake(20, 120, (self.view.frame.size.width - 40), 200)];
    [self.view addSubview:self.label];
    self.label.textColor = [UIColor blackColor];
    
    self.label.text = @"12";
    self.value = 12;
    self.lastValue = 120;

[self.label animationTextStartValue:self.value endValue:self.lastValue duration:3.0 complete:^(UILabel *label, CGFloat value) {
            label.text = [NSString stringWithFormat:@"%f", value];
            self.value = value;
            self.lastValue = (self.value * 3);
    }];

[20181119112806200.gif]: /images/20220416/dabc04a634ea423c92828ae17710c77d.png