JavaScript留言板效果程式碼例項

admin發表於2017-04-17
JavaScript

分享一段程式碼例項，它實現了簡單的留言板效果。

這裡主要演練的是對於dom元素的相關操作技巧，程式碼例項如下:

[HTML] 純文字檢視 複製程式碼執行程式碼
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<meta name="author" content="http://www.softwhy.com/" />
<title>螞蟻部落</title>
<style type="text/css">
* {
  margin: 0;
  padding: 0;
}
body, html {
  height: 100%;
  width: 100%;
}
#wrap {
  width: 600px;
  background: rgb(200,200,200);
  margin: 20px auto;
  padding: 10px;
}
li {
  list-style: none;
}
#content_view {
  padding: 10px;
}
#content_view li {
  padding: 10px 0;
  line-height: 22px;
}
#content_view #userName {
  height: 30px;
  width: 520px;
  font-size: 16px;
  vertical-align: top;
}
#content_view #content {
  width: 520px;
  height: 100px;
  font-size: 16px;
  vertical-align: top;
}
#content_view #submit {
  width: 100px;
  height: 30px;
  border: 1px solid gray;
  background: white;
  position: relative;
  left: 48px;
  font-size: 16px;
}
#comment_list h2 {
  margin-top: 10px;
}
#comment_list h3 {
  padding: 10px;
  background: mistyrose;
}
#comment_list p {
  padding: 10px;
  font-size: 14px;
  text-indent: 2em;
}
#comment_list a {
  text-decoration: none;
  float: right;
  top: 20px;
}
</style>
<script type="text/javascript">
window.onload = function() {
  var userName = document.getElementById("userName");
  var content = document.getElementById("content");
  var submitBtn = document.getElementById("submit");
  var ul = document.getElementById("comment_ul");
  var timer = null;
  submitBtn.onclick = function() {
    var name = userName.value;
    var comment_P = content.value;
 
    if (name == "" || comment_P == "") {
      alert("留言者的姓名和留言內容不能為空！");
      return;
    }
 
    userName.value = "";
    content.value = "";
    var li = document.createElement('li');
    li.innerHTML = '<h3>' + name + '</h3><p>' + comment_P + '<a href="###">刪除</a></p>';
    if (ul.children.length > 0) {
      ul.insertBefore(li, ul.children[0]);
    } else {
      ul.appendChild(li);
    }
 
    var start = 0;
    var end = li.offsetHeight;
 
    li.style.height = 0;
    var change = end - start;
    var t = 0;
    var endT = 20;
 
    clearInterval(timer);
    timer = setInterval(function() {
      t++;
      if (t == endT) {
        clearInterval(timer);
      }
 
      li.style.height = Tween.Bounce.easeOut(t, start, change, endT) + 'px';
    }, 30);
 
 
    var deleteAObj = li.getElementsByTagName('a')[0];
 
    deleteAObj.onclick = function() {
 
      var deleteLi = this.parentNode.parentNode;
      var start = li.offsetHeight;
      var end = 0;
      var change = end - start;
      var t = 0;
      var endT = 20;
      clearInterval(timer);
      timer = setInterval(function() {
        t++;
        if (t == endT) {
 
          ul.removeChild(deleteLi);
          clearInterval(timer);
        }
        li.style.height = Tween.Quart.easeIn(t, start, change, endT) + 'px';
      }, 30);
    }
  }
}
</script>
</head>
<body>
  <div id="wrap">
 
    <div id="content_view">
      <ul>
        <li>
          QQ：<input type="text" id="userName" />
        </li>
        <li>
          留言：<textarea name="" id="content" cols="30" rows="10"></textarea>
        </li>
        <li>
          <input type="button" value="提交" id="submit" />
        </li>
      </ul>
    </div>
 
    <div id="comment_list">
      <h2>顯示留言</h2>
      <ul id="comment_ul">
      </ul>
    </div>
 
  </div>
</body>
</html>

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