背景：页面上一个按钮，点击弹出上传框，从按钮的方法代码开始写：处理未选择文件阻止上传；通过判断选择文件的数量，显示或隐藏上传按钮；
在js中定义：
function uploadfile(){layer.open({type:1,title:'上传文件‘,area:['25%','400px'],content:'<div class="layui-form-item" style="margin-top:40px;">\<div class="layui-input-block">\<input class="layui-btn" type="button" id="choosefile" value="选择文件">\<span></span>\</div>\</div>\<div class="layui-form-item" style="margin-top:40px;">\<div class="layui-input-block">\<input class="layui-btn" type="button" id="uploadbtn" value="上传">\<span></span>\</div>\</div>‘，btn:['关闭'],btn1:function(idx,ele){layer.closeall();}})createupload();} var files ;function createupload(){$("#uploadbtn").hide();$("#choosefile").next().next("span").text("");layui.use(['upload'],function(){var uploadinst = upload.render({elem:'#choosefile',　url:' ',accept:'file',　auto:false,multiple:true,acceptmime:'application/vnd.ms-excel,application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',exts:'xls|xlsx',size:1024000,number:5,bindaction:'#uploadbtn',choose:function(obj){files = this.files = boj.pushfile();if(object.keys(files).length>0){ $("#uploadbtn").show(); }obj.preview(function(index,file,result){$("#choosefile").siblings("span").append("<div title='"+index+"'>"+file.name+"&nbsp;&nbsp;<span onclick='deletefile(\""+index+"\")'>&times;</span></div>")　if(index>0) {$("#uploadbtn").show() ;}})},alldone:function(obj){ if(obj.successful){layer.msg(obj.total+"个文件上传成功!");} },error:function(){layer.alert("上传成功!");}})}}function deletefile(index){delete files[index];$("#choosefile").siblings("span").find("div[title="+index+"]").remove();if(!object.keys(files).length>0){$("#uploadbtn").hide();} }
更多layui知识请关注layui使用教程栏目。
以上就是layui的upload组件使用和上传阻止的详细内容。