I am trying to contol a buttons state depending on a relevant text box. The names are the same other than the prefixes. The text boxes and buttons are located in a table on the page.
<asp:Table ID="Table1" runat="server" CssClass="table">
<asp:TableRow>
<asp:TableCell Width="15%">
<asp:Label ID="lblRequestHeader" runat="server" Text="Requested" CssClass="bold text-center"
Width="90%"></asp:Label>
</asp:TableCell>
<asp:TableCell Width="15%">
<asp:Label ID="lblApprovalHeader" runat="server" Text="Approval" CssClass="bold text-center"
Width="90%"></asp:Label>
</asp:TableCell>
<asp:TableCell Width="15%">
<asp:Label ID="lblApprovalTimeHeader" runat="server" Text="Date/Time of Approval"
CssClass="bold text-center" Width="90%"></asp:Label>
</asp:TableCell>
<asp:TableCell Width="15%">
<asp:Label ID="lblReadyHeader" runat="server" Text="Ready To Pick Up" CssClass="bold text-center"
Width="90%"></asp:Label>
</asp:TableCell>
<asp:TableCell Width="15%">
<asp:Label ID="lblCollectedHeader" runat="server" Text="Collected By TestHouse" CssClass="bold text-center"
Width="90%"></asp:Label>
</asp:TableCell>
<asp:TableCell Width="15%">
<asp:Label ID="lblDeliveredHeader" runat="server" Text="Delivered From TestHouse"
CssClass="bold text-center" Width="90%"></asp:Label>
</asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell Width="15%">
<asp:TextBox ID="txtRequestTime" runat="server" Width="90%"> </asp:TextBox>
</asp:TableCell>
<asp:TableCell Width="15%">
<asp:TextBox ID="txtApproval" runat="server" Width="90%"></asp:TextBox>
</asp:TableCell>
<asp:TableCell Width="15%">
<asp:TextBox ID="txtApprovalTime" runat="server" Width="90%"></asp:TextBox>
</asp:TableCell>
<asp:TableCell Width="15%">
<asp:TextBox ID="txtReadyTime" runat="server" Width="90%"></asp:TextBox>
</asp:TableCell>
<asp:TableCell Width="15%">
<asp:TextBox ID="txtCollectedTime" runat="server" Width="90%"></asp:TextBox>
</asp:TableCell>
<asp:TableCell Width="15%">
<asp:TextBox ID="txtDeliveredTime" runat="server" Width="90%"></asp:TextBox>
</asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell Width="15%">
</asp:TableCell>
<asp:TableCell Width="15%">
</asp:TableCell>
<asp:TableCell Width="15%">
</asp:TableCell>
<asp:TableCell Width="15%">
<asp:Button ID="btnReadyTime" runat="server" Text="Ready To Collect" Width="90%" />
</asp:TableCell>
<asp:TableCell Width="15%">
<asp:Button ID="btnCollectedTime" runat="server" Text="Collected" Width="90%" />
</asp:TableCell>
<asp:TableCell Width="15%">
<asp:Button ID="btnDeliveredTime" runat="server" Text="Delivered" Width="90%" />
</asp:TableCell>
</asp:TableRow>
</asp:Table>
The textbox is populated by a dataretrieval, and the state of the button is then set by the called method as follows:
txtReadyTime.Text = slabdetails.ReadyTimestamp.ToString();
textboxenabled(txtReadyTime);
This method modifies the textbox name to a button name, then attempts to find the button to enable/disable it.
public void textboxenabled(TextBox box)
{
string btnName = box.ID.Replace("txt", "btn");
try
{
Button btn = FindControl(btnName) as Button;
if (box.Text == "")
btn.Enabled = true;
else
btn.Enabled = false;
}
catch
{
}
}
However, despite the string matching the names of the buttons perfectly, the control returns as null. What can be done to deal with this issue?
With thanks to Matthew Watson, the FindControl has issues in projects using master pages. In order to find controls within a page, one must first drill down through the master page and its content manually:
This:
Button btn = FindControl(btnName) as Button;
Must take the format:
Button btn = this.Master.FindControl("MainContent").FindControl(btnName) as Button;