input输入框限制只能输入数字的方法实例(个人认为最好的)

<a-input type='number' />

// css部分 需要注意浏览器兼容问题
<style lang="css" scoped>
input::-webkit-outer-spin-button,
input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  appearance: none;
  margin: 0;
}

/* 火狐 */
input {
  -moz-appearance: textfield;
}

<input onkeyup="this.value=this.value.replace(/\D/g,'')" onafterpaste="this.value=this.value.replace(/\D/g,'')">

<input onkeyup="this.value=this.value.replace(/\D/g,'')" onafterpaste="this.value=this.value.replace(/\D/g,'')">

<input onkeyup="if(isNaN(value))execCommand('undo')" onafterpaste="if(isNaN(value))execCommand('undo')"> 
<input name=txt1 onchange="if(/\D/.test(this.value)){alert('只能输入数字');this.value='';}">

<input
   type="text"
   t_value=""
   o_value=""
   onkeypress="if(!this.value.match(/^[\+\-]?\d*?\.?\d*?$/))this.value=this.t_value;else this.t_value=this.value;if(this.value.match(/^(?:[\+\-]?\d+(?:\.\d+)?)?$/))this.o_value=this.value"
   onkeyup="if(!this.value.match(/^[\+\-]?\d*?\.?\d*?$/))this.value=this.t_value;else this.t_value=this.value;if(this.value.match(/^(?:[\+\-]?\d+(?:\.\d+)?)?$/))this.o_value=this.value"
   onblur="if(!this.value.match(/^(?:[\+\-]?\d+(?:\.\d+)?|\.\d*?)?$/))this.value=this.o_value;else{if(this.value.match(/^\.\d+$/))this.value=0+this.value;if(this.value.match(/^\.$/))this.value=0;this.o_value=this.value}"
/>

<input onkeyup="value=value.replace(/[\d]/g,'')"onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[\d]/g,''))"maxlength=10 name="Numbers"> 

<input onkeyup="value=value.replace(/[^\w\.\/]/ig,'')"> 

<input onKeyUp="value=value.replace(/[^\d|chun]/g,'')"> 

<input onKeyPress="if((event.keyCode<48 || event.keyCode>57) && event.keyCode!=46 || /\.\d\d$/.test(value))event.returnValue=false"> 

<input onkeyup="this.value=this.value.replace(/^(\-)*(\d+)\.(\d\d).*$/,'$1$2.$3')"> 

onkeypress="return event.keyCode>=4&&event.keyCode<=57"