我尝试在从内容页面访问母版页时找到一个控件，确切地说是一个图像按钮。以下是母版页html代码：
<body>
<form id="form1" runat="server">
<div class="navLeft">
<br />
<asp:ImageButton ID="imgbtnMooring" runat="server"
Height="60px" ImageUrl="~/Item/RibbonIcon/Dashboard.png" />
<br />
</div>
<div class="navTop">
</div>
<div class="banner">
<asp:ContentPlaceHolder id="ContentPlaceHolder1" runat="server">
</asp:ContentPlaceHolder>
</div>
<div class="divider">
<asp:ContentPlaceHolder id="ContentPlaceHolder2" runat="server">
</asp:ContentPlaceHolder>
</div>
<div class="content">
<asp:ContentPlaceHolder id="ContentPlaceHolder3" runat="server">
</asp:ContentPlaceHolder>
</div>
</form>
</body>
当我将以下代码放入内容页 aspx.cs 文件中时，我成功地做到了这一点
string validMooring = "";
comm = new SqlCommand("SELECT * FROM dbo.StructureCurrent", conn);
conn.Open();
reader = comm.ExecuteReader();
while (reader.Read())
{
validMooring = reader["StructureMooring"].ToString();
}
switch (validMooring)
{
case "YES":
(Page.Master.FindControl("imgbtnMooring") as ImageButton).Enabled = true;
(Page.Master.FindControl("imgbtnMooring") as ImageButton).ImageUrl = "~/Item/RibbonIcon/Dashboard.png";
break;
case "NO":
(Page.Master.FindControl("imgbtnMooring") as ImageButton).Enabled = false;
(Page.Master.FindControl("imgbtnMooring") as ImageButton).ImageUrl = "~/Item/RibbonIcon - Grey/DashboardGrey.png";
break;
default:
break;
}
现在我尝试制作一个名为 GeneralClass 的类文件，以便可以在任何内容页面中访问上述代码。 sql 命令只是从服务器中提取“是/否”值，所以我认为对于我的问题可以忽略它。
以下是 GeneralClass 类文件中的代码：
MasterPage masterPage = new MasterPage();
masterPage.MasterPageFile = "~/GeneralLayout.master";
string validMooring = "";
comm = new SqlCommand("SELECT * FROM dbo.StructureCurrent", conn);
conn.Open();
reader = comm.ExecuteReader();
while (reader.Read())
{
validMooring = reader["StructureMooring"].ToString();
}
switch (validMooring)
{
case "YES":
(masterPage.FindControl("imgbtnMooring") as ImageButton).Enabled = true;
(masterPage.FindControl("imgbtnMooring") as ImageButton).ImageUrl = "~/Item/RibbonIcon/Dashboard.png";
break;
case "NO":
(masterPage.FindControl("imgbtnMooring") as ImageButton).Enabled = false;
(masterPage.FindControl("imgbtnMooring") as ImageButton).ImageUrl = "~/Item/RibbonIcon - Grey/DashboardGrey.png";
break;
default:
break;
}
但不知何故，该行 (masterPage.FindControl("imgbtnMooring") as ImageButton) 返回空值。
谁能帮我解决这个问题吗？
