美好的一天，
我在MDI表单中遇到问题，有主表单，并有2个按钮，这些按钮导致子表单，其中一个表单允许您从数据库中选择一个类别，并在其中填充网格，一切正常，直到我使用事件如下的按钮将表单嵌入MDI：
Private Sub ButtonCatego_ItemClick(sender As Object, e As DevExpress.XtraBars.ItemClickEventArgs) Handles ButtonCatego.ItemClick
Dim addCategory As New AddCategory
addCategory.MdiParent = Me.MdiParent
addCategory.Show()
End Sub
当我使用普通事件时：
Private Sub ButtonCatego_ItemClick(sender As Object, e As DevExpress.XtraBars.ItemClickEventArgs) Handles ButtonCatego.ItemClick
AddCategory.Show()
End Sub
请帮帮我。谢谢
答案 0 :(得分：0)
您正在将<!doctype html>
<html>
<head>
<title>student</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" type="text/css" href="style.css">
<link rel="stylesheet" href="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
</head>
<body>
<div id="wrapper"><!--start wrapper-->
<div id="navbar"><!--start nav-->
<ul>
<li><a href="home.html">Home</li>
<li><a href="about.html">About us</li>
<li><a href="services.html">Services</li>
<li><a href="products.html">Products</li>
<li><a href="contact.html">Contact us</li>
</ul>
</div><!--end nav-->
<div id="myCarousel" class="carousel slide" data-ride="carousel"><!--carasel start-->
<!-- Indicators -->
<ol class="carousel-indicators">
<li data-target="#myCarousel" data-slide-to="0" class="active"></li>
<li data-target="#myCarousel" data-slide-to="1"></li>
<li data-target="#myCarousel" data-slide-to="2"></li>
<li data-target="#myCarousel" data-slide-to="3"></li>
<li data-target="#myCarousel" data-slide-to="4"></li>
</ol>
<!-- Wrapper for slides -->
<div class="carousel-inner" role="listbox">
<div class="item active">
<img src="D:\task\photo\h.jpg" alt="Home" height="400px">
<div class="carousel-caption">
<h3>Home</h3>
</div>
</div>
<div class="item">
<img src="D:\task\photo\as.jpg" alt="About us" height="400px">
<div class="carousel-caption">
<h3>About us</h3>
</div>
</div>
<div class="item">
<img src="D:\task\photo\s.jpg" alt="Services" height="400px">
<div class="carousel-caption">
<h3>Services</h3>
</div>
</div>
<div class="item">
<img src="D:\task\photo\p.jpg" alt="Products" height="400px">
<div class="carousel-caption">
<h3>products</h3>
</div>
</div>
<div class="item">
<img src="D:\task\photo\c.jpg" alt="Contact us" height="400px">
<div class="carousel-caption">
<h3>Contact us</h3>
</div>
</div>
</div>
<!-- Left and right controls -->
<a class="left carousel-control" href="#myCarousel" role="button" data-slide="prev">
<span class="glyphicon glyphicon-chevron-left" aria-hidden="true"></span>
<span class="sr-only">Previous</span>
</a>
<a class="right carousel-control" href="#myCarousel" role="button" data-slide="next">
<span class="glyphicon glyphicon-chevron-right" aria-hidden="true"></span>
<span class="sr-only">Next</span>
</a>
</div><!--end carosel-->
<div class="container-fluid text-center bg-grey"><!--boxes-->
<div class="row text-center">
<div class="col-sm-4">
<div class="thumbnail">
<img src="D:\task\photo\i.jpg" alt="Innovation">
<p><strong>Innovation</strong></p>
</div>
</div>
<div class="col-sm-4">
<div class="thumbnail">
<img src="D:\task\photo\cr.png" alt="Creative">
<p><strong>Creativity</strong></p>
</div>
</div>
<div class="col-sm-4">
<div class="thumbnail">
<img src="D:\task\photo\po.jpg" alt="Positive">
<p><strong>Positivity</strong></p>
</div>
</div>
</div><!--end boxes-->
<div id="con">
<div class="contact">
<h1>Address</h1>
<p><span class="glyphicon glyphicon-map-marker"></span>
Abc private limited
no54,2ndstreet,
madipakkam,
chennai-67.
</p>
<p><span class="glyphicon glyphicon-envelope"></span> ABCPVT@gmail.com</p>
</div>
<div class="enquiry">
<h1>Enquiry Form</h1>
<table border="0" align="center">
<form name="form" action="email.php" id="form" method="post">
<tr>
<tr>
<td>Name</td>
<td><input name="name" placeholder="Name" type="text" value=""></td>
</tr>
<tr>
<td>Email</td>
<td><input name="email" placeholder="Email" type="text" value=""></td>
</tr>
<tr>
<td>Phone</td>
<td><input name="phone" placeholder="phonenumber" type="text" value=""></td>
</tr>
<tr>
<td>Message</td>
<td><textarea name="msg" placeholder="Type your text here..."></textarea></td>
</tr>
<td colspan="2" style="text-align:center"><input id="send" name="submit" type="submit" value="Submit"></td>
</tr>
</form>
</table>
</div>
</div>
<div class="footer">
copyrights © to WWW.abcpvt.com
<img src="E:\photos\fb.png" alt="fb"/>
<img src="E:\photos\ln.png" alt="tweet"/>
<img src="E:\photos\tw.png" alt="linkedin"/>
</div>
</div><!--end wrapper-->
</body>
</html>设置为当前表单的MDI父级。如果addCategory.MdiParent是您的主要表单，那么它就不会拥有MDI父级，这就是您无法使用它的原因。
将Me设置为addCategory.MdiParent，它应解决您的问题：
Me