无依赖的、轻量级的 JavaScript 类，可以用来快速创建以一种更有趣的动画方式显示数值数据。尽管它的名字叫 countUp，但其实可以在两个方向进行变化，这是根据你传递的 startVal 和 endVal 参数判断的。 再加上滚轮事件判断……
可配置的参数：
target = 目标元素的 ID；
startVal = 开始值；
endVal = 结束值；
decimals = 小数位数，默认值是0；
duration = 动画延迟秒数，默认值是2；
【
var options = {
useEasing: true,
useGrouping: true,
separator: ',',
decimal: '.',
};
var demo = new CountUp('myTargetElement', 0, 4068, 0, 2.5, options);
if (!demo.error) {
demo.start();
} else {
console.error(demo.error);
}
】
Options (defaults in parentheses):
interface CountUpOptions {
startVal?: number; // number to start at (0)
decimalPlaces?: number; // number of decimal places (0)
duration?: number; // animation duration in seconds (2)
useGrouping?: boolean; // example: 1,000 vs 1000 (true)
useEasing?: boolean; // ease animation (true)
smartEasingThreshold?: number; // smooth easing for large numbers above this if useEasing (999)
smartEasingAmount?: number; // amount to be eased for numbers above threshold (333)
separator?: string; // grouping separator (',')
decimal?: string; // decimal ('.')
// easingFn: easing function for animation (easeOutExpo)
easingFn?: (t: number, b: number, c: number, d: number) => number;
formattingFn?: (n: number) => string; // this function formats result
prefix?: string; // text prepended to result
suffix?: string; // text appended to result
numerals?: string[]; // numeral glyph substitution
}const countUp = new CountUp('targetId', 5234);
if (!countUp.error) {
countUp.start();
} else {
console.error(countUp.error);
}Pass options:
const countUp = new CountUp('targetId', 5234, options);with optional callback:
countUp.start(someMethodToCallOnComplete);
// or an anonymous function
countUp.start(() => console.log('Complete!'));Other methods:
Toggle pause/resume:
countUp.pauseResume();Reset the animation:
countUp.reset();Update the end value and animate:
countUp.update(989);