localStorage實現便簽小程序

2019-11-19 18:48:15

字體：大中小

來源：轉載

供稿：網友

前言：今天寫了個小練習，把這幾天看的東西鞏固一下，在這個程序中用到了localStorage存儲和json串的轉換。

下面是具體的實現代碼：

（1）首先判斷是否存在用戶，從而顯示相應的界面

function isUser(){  var storage = window.localStorage;  if (storage.user != undefined)  {    document.getElementById("showmess").style.display = "block";    document.getElementById("fillmess").style.display = "none";  }  else  {    document.getElementById("showmess").style.display = "none";    document.getElementById("fillmess").style.display = "block";  }  }

（2）存儲用戶信息

var pic; //全局變量存儲圖片信息/*從本地電腦獲得圖片*/ function add_files(files) {        if (files.length) {          var file = files[0];          var reader = new FileReader();          reader.onload = function(e) {            document.getElementById("userpic").src = e.target.result;            pic = e.target.result;          }          reader.readAsDataURL(file);        }      }function saveUserMess(){  var name = document.getElementById("username").value;  if (name != "")  {    var storage = window.localStorage;    var jsonObj = {                name:name,                icon:pic              };       var user = JSON.stringify(jsonObj);      storage.setItem("user",user);  }  else  {    alert("昵稱不為空");   }}

（3）用戶輸入便簽內容，并保存

function save_diary(){ var headle = document.getElementById("headle").value; var cont = document.getElementById("diary").value; if (headle != "" && cont != "") {  var storage = window.localStorage;  if (storage.diary != undefined)  {   var diary = storage.getItem("diary");   var jsonObj = JSON.parse(diary);   var diaryItem = {        headle:headle,        diary:cont,        date:new Date()       };    jsonObj.push(diaryItem);   var data = JSON.stringify(jsonObj);   storage.setItem("diary",data);   }  else  {   var jsonObj = [{        headle:headle,        diary:cont,        date:new Date()       }];    var diary = JSON.stringify(jsonObj);   storage.setItem("diary",diary);  } } else {  alert("標題和內容不為空哦");  }}

（4）將用戶便簽信息顯示在見面

function showDiary(){  var storage = window.localStorage;  var mess = JSON.parse(storage.user);  if (storage.diary != undefined)  {    var json = JSON.parse(storage.diary);    var div_id = document.getElementById("diarymess");    for (var i = 0; i < json.length; i++)    {      div_id.innerHTML+='<div><button class="btn btn-success"'+'type="button" id="dropdownMenu" onclick="show(this)"><div class="col-md-4"><img src='+mess.icon+' class="img-circle size" id="userpic"><br><font style="text-align:center">'+mess.name+'</font></div><div class="col-md-8"><h2>'+json[i].headle+'</h2><font>'+json[i].date+'</font></div><span class="caret" style="margin-top:50px;">'+'</span></button><p style="display:none">'+json[i].diary+'</p><div>';     }  }}