<!DOCTYPE html>action="form-action.php"Time: type="time" id="myTime" name="usr_time"type="submit"点击 "点我" 按钮为 time 字段设置 required 属性。提示: 在点击 "点我" 按钮前后点击 "提交" 按钮查看效果onclick="myFunction()"点我id="demo"function myFunction() {document.getElementById("myTime").required = true;document.getElementById("demo").innerHTML = " required 属性已设置,time 字段在标题提交前为必填字段。";}