记得一句JS就能搞定的？
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1<input onafterpaste="this.value=this.value.replace(/\D/g,'')" onkeyup="this.value=this.value.replace(/\D/g,'')"/>
or
1<input name="txt1" onchange="if(/\D/.test(this.value)){alert('只能输入数字');this.value='';}"/>
or
1<input onafterpaste="if(isNaN(value))execCommand('undo')" onkeyup="if(isNaN(value))execCommand('undo')"/>
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可以使用下面这个，但是不推荐，会导致ie死机，
1<input ondragenter="return false" onpropertychange="if(/\D/g.test(value))value=value.replace(/\D/g,'')" style="ime-mode:disabled"/>