ASP.net错误：Control 'ctl00_ctl00_ContentPlaceHolder2_ContentPlaceHolderRight_ListView1_ctrl0_DeleteButton' of type 'Button' must b

表现：

当然也可能是另外一个什么控件必须放置在Form里边。



原因：

如果是普通情况，当然直接加一个Form就可以了，但如果是使用了master page，这个错误的真正原因是在master page中 ContentPlaceHolder被错误放置到<form>外面了：



<form id="form1" runat="server">
<asp:LinkButton ID="PB" runat="server"><b>P</b>roduct Backlog</asp:LinkButton>
<asp:LinkButton ID="SB" runat="server"><b>S</b>print Backlog</asp:LinkButton>
</form>

<asp:ContentPlaceHolder id="ContentPlaceHolder1" runat="server">
</asp:ContentPlaceHolder>
<asp:ContentPlaceHolder id="ContentPlaceHolder2" runat="server">
</asp:ContentPlaceHolder>



改为：



<form id="form1" runat="server">
<asp:LinkButton ID="PB" runat="server"><b>P</b>roduct Backlog</asp:LinkButton>
<asp:LinkButton ID="SB" runat="server"><b>S</b>print Backlog</asp:LinkButton>

<asp:ContentPlaceHolder id="ContentPlaceHolder1" runat="server">
</asp:ContentPlaceHolder>
<asp:ContentPlaceHolder id="ContentPlaceHolder2" runat="server">
</asp:ContentPlaceHolder>
</form>

一切正常。