基本

• hidden
  可以为true或false，在js中可以直接修改为yes还是false，例如

<select hidden=true id="member"></select>

<script>
  var memberSelect = document.getElementById("member");
  memberSelect.hidden = false;
</script>

• 获取某一个控件
  document.getElementById，例

var serviceAddress = document.getElementById("serviceAddress").value;

• 解决中文乱码

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

• 打印数据到控制台

console.log("2122212");

select

• 清空所有选项
  options.length=0，例如

var memberSelect = document.getElementById("member");
memberSelect.options.length=0;

• 添加选项

memberSelect.add(new Option(name,key));

• 读取现在所选择的内容的参数

var memberSelect = document.getElementById("member");
console.log(memberSelect.value);

• 手动切换选择

<select  onchange="changeMember()" id="member"></select>

button

• 点击按钮的响应

<button type="button" onclick="getConfig()">获取配置信息</button>

输入框

• 对应控件的值

<input id="projectName" type="text" value="这个是显示出来的值" />

选择文件

<input type="file" accept="text/plain" />
其中accept标识对文件格式的显示，具体限制方式如下所示，源自 https://blog.csdn.net/emoven/article/details/54908077

*.ac3	audio/ac3	AC3 Audio
*.asf	allpication/vnd.ms-asf	Advanced Streaming Format
*.au	audio/basic	AU Audio
*.css	text/css	Cascading Style Sheets
*.csv	text/csv	Comma Separated Values
*.doc	application/msword	MS Word Document
*.dot	application/msword	MS Word Template
*.dtd	application/xml-dtd	Document Type Definition
*.dwg	image/vnd.dwg	AutoCAD Drawing Database
*.dxf	image/vnd.dxf	AutoCAD Drawing Interchange Format
*.gif	image/gif	Graphic Interchange Format
*.htm	text/html	HyperText Markup Language
*.html	text/html	HyperText Markup Language
*.jp2	image/jp2	JPEG-2000
*.jpe	image/jpeg	JPEG
*.jpeg	image/jpeg	JPEG
*.jpg	image/jpeg	JPEG
*.js	text/javascript， application/javascript	JavaScript
*.json	application/json	JavaScript Object Notation
*.mp2	audio/mpeg， video/mpeg	MPEG Audio/Video Stream， Layer II
*.mp3	audio/mpeg	MPEG Audio Stream， Layer III
*.mp4	audio/mp4， video/mp4	MPEG-4 Audio/Video
*.mpeg	video/mpeg	MPEG Video Stream， Layer II
*.mpg	video/mpeg	MPEG Video Stream， Layer II
*.mpp	application/vnd.ms-project	MS Project Project
*.ogg	application/ogg， audio/ogg	Ogg Vorbis
*.pdf	application/pdf	Portable Document Format
*.png	image/png	Portable Network Graphics
*.pot	application/vnd.ms-powerpoint	MS PowerPoint Template
*.pps	application/vnd.ms-powerpoint	MS PowerPoint Slideshow
*.ppt	application/vnd.ms-powerpoint	MS PowerPoint Presentation
*.rtf	application/rtf， text/rtf	Rich Text Format
*.svf	image/vnd.svf	Simple Vector Format
*.tif	image/tiff	Tagged Image Format File
*.tiff	image/tiff	Tagged Image Format File
*.txt	text/plain	Plain Text
*.wdb	application/vnd.ms-works	MS Works Database
*.wps	application/vnd.ms-works	Works Text Document
*.xhtml	application/xhtml+xml	Extensible HyperText Markup Language
*.xlc	application/vnd.ms-excel	MS Excel Chart
*.xlm	application/vnd.ms-excel	MS Excel Macro
*.xls	application/vnd.ms-excel	MS Excel Spreadsheet
*.xlt	application/vnd.ms-excel	MS Excel Template
*.xlw	application/vnd.ms-excel	MS Excel Workspace
*.xml	text/xml， application/xml	Extensible Markup Language
*.zip	aplication/zip	Compressed Archive

alert

alert("Problem retrieving XML data");

http请求数据

• get

var request = null;
      
function getConfig() {
     var url = "http://www.baidu.com";
     request = new XMLHttpRequest();
     request.onreadystatechange = state_Change;
     request.open("GET", url);
     request.send(null);
}

function state_Change() {
     if (request.readyState == 4) {// 4 = "loaded"
          if (request.status === 200) {// 200 = OK
               var uploadJson = JSON.parse(this.response);
          }
          else {
                alert("Problem retrieving XML data");
           }
    }
}

js读取用户所选择的文件

var selectedFile = document.getElementById('crashFile').files[0];
//创建文件读取对象
var fileReader = new FileReader();
//文件载入成功
fileReader.onload = function () {
  var fileResult = fileReader.result;
  console.log(fileResult);
}
//载入文件
fileReader.readAsText(selectedFile);