<script type="text/javascript">
   var p = /^(?=.*\d)(?=.*[a-zA-Z])(?=.*[\u4e00-\u9fa5]).*$/ 
   var arr=["asdf汉字","1a^","1A","11","1a2A","a1b2c汉字","a1汉字b2cA"]
   for(var i=0;i<arr.length;i++){
    document.write(arr[i].replace(" ","&nbsp;")+":"+p.test(arr[i])+"<br/>");
   }
</script>

------解决方案--------------------
/^[a-zA-Z0-9\u4E00-\u9FFF]{2,10}$/

------解决方案--------------------
一时搞错，再来

HTML code
<script type="text/javascript">
   var p = /^(?=.*\d)(?=.*[a-zA-Z])(?=.*[\u4e00-\u9fa5])[\da-zA-Z\u4e00-\u9fa5]+$/ 
   var arr=["asdf汉字","1a^","1A","11","1a2A","a1b2c汉字","a1汉字b2cA!"]
   for(var i=0;i<arr.length;i++){
    document.write(arr[i].replace(" ","&nbsp;")+":"+p.test(arr[i])+"<br/>");
   }
</script>

------解决方案--------------------
哦，我那个是三者都一定要输入了，结合2楼的话用/^[a-zA-Z0-9\u4E00-\u9FFF]+$/吧

------解决方案--------------------
探讨

要求用户名可以是数字、字母、汉字，其他的字符都不允许，怎么写？看书写了几次都不对


------解决方案--------------------
^[0-9a-zA-z\u4E00-\u9FA5]+$