koa2 接收post参数

koa2接收Post参数由于没有在上下文对象上解析，所以需要用node 原生req解析。

获取到的参数，要注意转码问题。

const Koa = require('koa');const app = new Koa();
app.use(async(ctx)=>{
if(ctx.url === '/' && ctx.method === 'GET'){
//显示表单页面
let html = `
<h1> KOA2 request post</h1>
<form method='post' action='/'>
<p>username: <input name="username"/></p>
<p>age: <input name="age"/></p>
<p>website: <input name="website"/></p>
<input type="submit" />
</form>
`;
ctx.body = html;
}else if(ctx.url === '/' && ctx.method === 'POST'){
let postData = await parsePostData(ctx);
let result = parseQueryStr(postData)
ctx.body = result;
}else{
ctx.body = '<h1>404!</h1>'
}
});function parsePostData(ctx){
return new Promise((resolve,reject)=>{
try {
let postdata = '';
ctx.req.addListener('data',(data)=>{
postdata += data;
});
ctx.req.on("end",function(){
resolve(postdata);
})
} catch (error) {
reject(error);
}
});
}function parseQueryStr(queryStr){
let queryData = {};
let queryList = queryStr.split('&');
console.log(queryList.entries())
for(let [index,queryStr] of queryList.entries()){
let itemArr = queryStr.split("=");
queryData[itemArr[0]] = decodeURIComponent(itemArr[1]); //转码
}
return queryData;
}app.listen(3000,()=>{
console.log("app starting ...")
});