input 只能输入数字（或小数点数字）

<input v-model="trainTime" type="text" class="input_class" placeholder="请输入" @input="clickTrainTime"/>

//纯数字
clickTrainTime(e){
	const val = e.detail.value;
	const zero = /^(0{2,})|[^0-9]/g;
	let final = '';
	if (!val) {
		final = '';
	} else {
		final = val.toString().replace(zero, val => {
			return '';
		});
	
		if (final.split('')[0] * 1 === 0) {
			final = final.slice(1) - 0 || '';
		}
	}
	this.$nextTick(() => {
		this.trainTime = final.toString() || '';
	});
},

//带小数点的
clickTrainTime(e){
	const v = e.detail.value;
	const zero = /^(0{2,})|[^0-9,.]/g;
	let final = '';
	if (!v) {
		final = '';
	} else {
		final = v.toString().replace(zero, v => {
			return '';
		});
		console.log(final.split(''))
		if(final.split('').indexOf(".") == -1){
			const zero1 = /^(0{2,})|[^0-9]/g;
			if(final.split('').length > 1){
				if (final.split('')[0] * 1 === 0 ) {
					final = final.slice(1) - 0 || '';
				}
			}
		}else{
			var arr=[]
			final.split('').forEach((item,index)=>{
				if(item == '.'){
					arr.push(item)
				}
			})
			if(arr.length == 1){
			}else{//如果有小数点了，再加点清除
				const zero1 = /^(0{2,})|[^0-9]/g;
				if (final.split('')[final.split('').length-1]  === '.' ) {
					final = final.substring(0, final.length - 1);
				}
			}
		}
	}
	this.$nextTick(() => {
		this.trainTime = final.toString() || '';
	});
}