Prototype - 表单 focusFirstElement() 方法



此方法为表单的第一个元素赋予键盘焦点。

这很有用,因为它通过将焦点放在搜索表单或联系方式表单等页面加载上,而用户可以随时开始键入,从而提高了网站的可用性。

语法

form.focusFirstElement();

返回值

它返回 HTMLFormElement。

示例

<html>
   <head>
      <title>Prototype examples</title>
      <script type = "text/javascript" src = "/javascript/prototype.js"></script>
      
      <script>
         function showResult() {
            var form = $('example'); 
            form.focusFirstElement(); 
         }
      </script>
   </head>

   <body>
      <p>Click the button to see the result.</p>
      <br />

      <form id = "example" action = "#" onsubmit = "return false">
         <fieldset>
            <legend>User info</legend>
            <div>
               <label for = "username">Username:</label> 
               <input name = "username" id = "username" value = "Sulien" type = "text">
            </div>
            <div>
               <label for = "age">Age:</label> 
               <input name = "age" id = "age" value = "23" size = "3" type = "text">
            </div>
            <div>
               <label for = "hobbies">Your hobbies are:</label>
               <select name = "hobbies" id = "hobbies" multiple = "multiple">
                  <option>coding</option>
                  <option>swimming</option>
                  <option>hiking</option>
                  <option>drawing</option>
               </select>
            </div>
         </fieldset>
      </form>
      <br />
      
      <input type = "button" value = "Result" onclick = "showResult();"/>
   </body>
</html>

输出

prototype_form_management.htm
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