//导出excelfunction tableToExcel(){
var arrSor = ["sorttable10","sorttable30","sorttable60","sorttable120"]
let str = ""
for (var k = 0k <arrSor.lengthk++) {
var tab=document.getElementById(arrSor[k])
var rows=tab.rows
const jsonData = []
for(var i=2i<rows.lengthi++){ //遍历表格的行
var json = {}
for(var j=0j<rows[i].cells.lengthj++){ //遍历每行的列
json[(i+1)+"-"+(j+1)] = rows[i].cells[j].innerHTML
}
jsonData.push(json)
}
//列标题
let str1 = "<tr><td align='center' colspan='5'><b>最大"+arrSor[k].substring(9,arrSor[k].length)+"分钟雨量</b></td></tr>"
let str2 = "<tr align='center'><th>站点</th><th>站名</th><th>雨量最大值</th><th>降水时段</th><th>落入最大降水时段</th></tr>"
//循环遍历，每行加入tr标签，每个单元格加td标签
for(let i = 0 i <jsonData.length i++ ){
str2+='<tr>'
for(let item in jsonData[i]){
//增加\t为了不让表格显示科学计数法或者其他格式
var itemTem= jsonData[i][item]
if (itemTem == "暂无数据") {
str2+=`<td colspan='5' align='center'>${ itemTem + '\t'}</td>`
}else {
str2+=`<td align='center'>${ itemTem + '\t'}</td>`
}
}
str2+='</tr>'
}
let str3 = "<tr><td colspan='5'></td></tr>"
str += (str1 + str2 + str3)
}
let worksheet = '雨量最大值'
let uri = 'data:application/vnd.ms-excelbase64,'
//下载的表格模板数据
let template = `<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns="http://www.w3.org/TR/REC-html40"><head><meta charset='UTF-8'><!--[if gte mso 9]><xml>
<x:ExcelWorkbook><x:ExcelWorksheets><x:ExcelWorksheet>
<x:Name>${worksheet}</x:Name><x:WorksheetOptions><x:DisplayGridlines/></x:WorksheetOptions></x:ExcelWorksheet></x:ExcelWorksheets></x:ExcelWorkbook></xml><![endif]-->
<style type="text/css">
table {border: 1px solid #000000}
table tr td b {background:#FFFFFFcolor:#3D3D3Dfont-size:24pxborder: 1px solid #000000}
table th {background:#AEE1FEcolor:#3D3D3Dfont-size:20pxborder: 1px solid #000000}
table td {background:#FFFFFFcolor:#3D3D3Dfont-size:20pxborder: 1px solid #000000}</style>
</head><body><table>${str}</table></body></html>`
//下载模板
// window.location.href = uri + this.base64(template)
var link = document.createElement("a")
link.href = uri + this.base64(template)
link.download = "雨量最大值-" +new Date().format("yyyy年MM月dd日 h时")+ ".xls"
link.style = "visibility:hidden"
document.body.appendChild(link)
link.click()
document.body.removeChild(link)}//输出base64编码function base64 (template) {
return window.btoa(unescape(encodeURIComponent(template))) }
解析：
遍历取出表，顺序是行从上往下，列从左往右，将数据存进数组，下面再拼接成表。
image.png
参考文章：https://blog.csdn.net/hhzzcc_/article/details/80419396
第一种方法（大量数据导出）
//导出excelfunction tableToExcel() {
var arrSor = ["sorttable10","sorttable30","sorttable60","sorttable120"]
let str = ""
for (var k = 0k <arrSor.lengthk++) {
var tab=document.getElementById(arrSor[k])
var rows=tab.rows
const jsonData = []
for(var i=2i<rows.lengthi++){ //遍历表格的行
var json = {}
for(var j=0j<rows[i].cells.lengthj++){ //遍历每行的列
if (rows[i].cells[j].outerHTML.indexOf("rgb(255, 255, 0)") != -1) {
json["yellow"+(i+1)+"-"+(j+1)] = rows[i].cells[j].innerHTML
}else {
json[(i+1)+"-"+(j+1)] = rows[i].cells[j].innerHTML
}
}
jsonData.push(json)
}
//列标题
let str1 = "<tr><td colspan='5' align='center' style='background-color:#FFFFFFfont-size:24pxborder: 1px solid #000000'><b>最大"
+arrSor[k].substring(9,arrSor[k].length)+"分钟雨量</b></td></tr>"
let str2 = "<tr>" +
"<th style='background-color:#AEE1FEfont-size:22pxborder: 1px solid #000000' align='center'>站点</th>" +
"<th style='background-color:#AEE1FEfont-size:22pxborder: 1px solid #000000' align='center'>站名</th>" +
"<th style='background-color:#AEE1FEfont-size:22pxborder: 1px solid #000000' align='center'>雨量最大值</th>" +
"<th style='background-color:#AEE1FEfont-size:22pxborder: 1px solid #000000' align='center'>降水时段</th>" +
"<th style='background-color:#AEE1FEfont-size:22pxborder: 1px solid #000000' align='center'>落入最大降水时段</th></tr>"
//循环遍历，每行加入tr标签，每个单元格加td标签
for(let i = 0 i <jsonData.length i++ ){
str2+="<tr align='center'>"
for(let item in jsonData[i]){
if (item.indexOf("yellow") != -1) {//取列数等于3
//增加\t为了不让表格显示科学计数法或者其他格式
var itemTem= jsonData[i][item]
if (itemTem == "暂无数据") {
str2+=`<td colspan='5' style='background-color:#FFFF00font-size:22pxborder: 1px solid #000000'> ${ itemTem + '\t'}</td>`
}else {
str2+=`<td style='background-color:#FFFF00font-size:22pxborder: 1px solid #000000'> ${ itemTem + '\t'}</td>`
}
}else {
//增加\t为了不让表格显示科学计数法或者其他格式
var itemTem= jsonData[i][item]
if (itemTem == "暂无数据") {
str2+=`<td colspan='5' style='background-color:#FFFFFFfont-size:22pxborder: 1px solid #000000'> ${ itemTem + '\t'}</td>`
}else {
str2+=`<td style='background-color:#FFFFFFfont-size:22pxborder: 1px solid #000000'> ${ itemTem + '\t'}</td>`
}
}
}
str2+='</tr>'
}
let str3 = "<tr><td colspan='5' style='background-color:#FFFFFFborder: 1px solid #000000'></td></tr>"
str += (str1 + str2 + str3)
}
var tableHtml="<html><head><meta charset='UTF-8'></head><body><table>"+str+"</body></html>"
var excelBlob = new Blob([tableHtml], {type: 'application/vnd.ms-excel'})
var fileName = "雨量最大值-"+new Date().format("yyyy年MM月dd日 h时")+".xls"
if(isIE()){
window.navigator.msSaveOrOpenBlob(excelBlob,fileName)
}else{
var oa = document.createElement('a')
oa.href = URL.createObjectURL(excelBlob)
oa.download = fileName
document.body.appendChild(oa)
oa.click()
}} //判断是否IE浏览器function isIE() {
if (!!window.ActiveXObject || "ActiveXObject" in window) {
return true
} else {
return false
}}
参考文章：https://blog.csdn.net/qq_34169240/article/details/84231226
把看到的区域当画布，创建足够能展现界面的Dom就够了。比如一个屏幕的高度一般是800像素左右，假设一条记录占用的高度是20像素，我们只用创建40个对象即可。
接下来就是对这40个对象进行数据填充，通过滚动条调整填充数据的起始下标。
10W条记录，IE下有些卡
<style type="text/css">
.panel{
overflow:scroll
width:200px
height:80%
}
.panel .scroll{
}
.item{
width:500px
height:20px
}
.odd{
background-color:#ccc
}
.items{
overflow:hidden
position:absolute
}
.red{
color:red
}
.green{
color:green
}
</style>
<script>
window.console = window.console || { log: function() {} }
function absolutePoint(element) {
var result = [element.offsetLeft, element.offsetTop]
element = element.offsetParent
while (element) {
result[0] += element.offsetLeft
result[1] += element.offsetTop
element = element.offsetParent
}
return result
}
function ListView(options){
options = options || {}
var self = this,
$C = function(tagName) { return document.createElement(tagName)}, // 创建节点
p,
height,
item_height, // 项高
view_count, // 可见项条数
parent = options.parent || document.body, // 容器
height, // 面板历史高度
div_panel = $C("div"),
div_scroll = $C("div"),
div_items = $C("div"),
div_items_list = [$C("div")],
freed = [div_panel, div_scroll, div_items]// 可释放的对象
div_panel.className = "panel"
parent.appendChild(div_panel)
div_items.className = "items"
document.body.appendChild(div_items)
div_scroll.className = "scroll"
div_panel.appendChild(div_scroll)
div_panel.onscroll = function() {
doChange()
}
div_panel.onresize = function() {
doChange()
}
div_items_list[0].className = "item"
div_items.appendChild(div_items_list[0])
div_scroll.style.width = div_items_list[0].clientWidth + "px"
item_height = div_items_list[0].clientHeight
p = absolutePoint(div_panel)
with(div_items.style) {
left = p[0] + "px"
top = p[1] + "px"
width = div_panel.clientWidth
height = div_panel.clientHeight
}
/**
* 界面改变
*/
function doChange() {
if (!item_height) return
var i, div
if (height != div_panel.clientHeight) {
height = div_panel.clientHeight
view_count = parseInt(height / item_height)
for (i = div_items_list.lengthi <view_counti++) {
div = $C("div")
div.className = "item" + (i % 2 == 0 ? "" : " odd")
div_items.appendChild(div)
div_items_list.push(div)
}
for (i = 0i <div_items_list.lengthi++) {
div_items_list[i].style.display = i <view_count ? "" : "none"
}
div_scroll.style.height = div_panel.clientHeight + options.count - view_count + "px"
console.log(["view_count", view_count])
}
div_items.scrollLeft = div_panel.scrollLeft
if (!options.ondrawitem) return
i = Math.min(view_count, div_items_list.length)
while(i--) {
// 重新绘制
options.ondrawitem(i + div_panel.scrollTop, div_items_list[i])
}
}
doChange()
this.doChange = doChange
/**
* 释放Dom对象
*/
this.dispose = function() {
var i = freed.length
while(i--) {
freed[i].parentNode.removeChild(freed[i])
}
i = freed.length
while(i--) {
div_items_list[i].parentNode.removeChild(div_items_list[i])
}
}
}
function format(template, json) {
if (!json) return template
return template &&template.replace(/\$\{(.+?)\}/g, function() {
return json[arguments[1]]
})
}
window.onload = function() {
var i = 100000, data = new Array(i)
while(i--) {
data[i] = { index: i, random: Math.random(), key: (+new Date()).toString(36) }
}
var listview = new ListView({
count: data.length,
ondrawitem: function(i, div) {
div.innerHTML = format(" <em>${index} </em> <span class=\"red\">${random} </span> <span class=\"green\">${key} </span>", data[i])
}
})
}
</script>
1、打开HTML5软件。2、点击文件按钮。
3、选择文件使用驱动为JavaScript。
4、点击创建。
5、将大数据地图板块的代码输入。
6、点击运行即可显示。
