Objects disappear in TemplateFields on postback

  • Thread starter Thread starter Robert Fernandez
  • Start date Start date
R

Robert Fernandez

I've got a gridview with BoundFields and TemplateFields and a
linkbutton with a CommandName="Select". When I click on this
linkbutton the TemplateField objects disappear on postback but the
BoundFields still have their data. Also the SelectedIndexChanged
event is never hit. Why is this happening?

-----------------------------------
<asp:GridView ID="gvSearchResults" runat="server"
AutoGenerateColumns="false" AutoGenerateSelectButton="false"
GridLines="none" DataKeyNames="entity_uid" SelectedIndex="0"
OnRowDataBound="gvSearchResults_OnRowDataBound"
OnSelectedIndexChanged="gvSearchResults_SelectedIndexChanged" Font-
Size="x-Small" CellSpacing="1">
<Columns>

<asp:TemplateField>
<ItemTemplate>
<asp:LinkButton ID="lbDetail" runat="server"
CommandName="Select" Text="View Detail" />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate>
<asp:Label ID="lblRecordInfo" runat="server" />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate>
<asp:Image ID="imgPhoto" runat="server" />
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField ReadOnly="true" HeaderText="FName"
DataField="FName" HeaderStyle-Font-Bold="true" />
<asp:BoundField ReadOnly="true" HeaderText="LName"
DataField="LName" HeaderStyle-Font-Bold="true" />
<asp:BoundField ReadOnly="true" HeaderText="GradYear"
DataField="GradYearDegree" HeaderStyle-Font-Bold="true" />
<asp:BoundField ReadOnly="true" HeaderText="&nbsp;Cohort&nbsp;"
DataField="cohort" HeaderStyle-Font-Bold="true" />
<asp:BoundField ReadOnly="true" HeaderText="DegreePrgoram"
DataField="DegreeProgram" HeaderStyle-Font-Bold="true" />
<asp:TemplateField HeaderText="PrefEmail" HeaderStyle-Font-
Bold="true">
<ItemTemplate>
<asp:HyperLink ID="hplPrefEmail" runat="server"
ForeColor="darkBlue" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
<AlternatingRowStyle BackColor="white" />
<RowStyle BackColor="beige" />
</asp:GridView>
----------------------------------------------------------------

protected void Page_Load(object sender, EventArgs e)
{

if (!IsPostBack)
{
DataSet dsSearchResults =
SQLRoutines.SearchRecords(P);
Trace.Write("Count:",
dsSearchResults.Tables[0].Rows.Count.ToString());
gvSearchResults.DataSource = dsSearchResults;
gvSearchResults.DataBind();
}

}


protected void gvSearchResults_SelectedIndexChanged(object sender,
EventArgs e)
{
SelectedUID = (string)gvSearchResults.SelectedValue;
Trace.Write("SelectedIndexChanged", SelectedUID);
Server.Transfer("SearchResultsBio.asp", true);
}

Thanks,
Robert
 
First, you have to create the objects early enough. The SelectedIndexChanged
event is not firing because the object doesn't exist yet. You have to call
your databinding code much earlier. You can try the OnInit event, or the
OnPreLoad event insteat. Page Load is just too late in the scheme of things
as it occurs after postback. You'll need to eliminate the test for postback,
the controls will need to be recreated each time.


--
Hope this helps,
Mark Fitzpatrick
Former Microsoft FrontPage MVP 199?-2006

Robert Fernandez said:
I've got a gridview with BoundFields and TemplateFields and a
linkbutton with a CommandName="Select". When I click on this
linkbutton the TemplateField objects disappear on postback but the
BoundFields still have their data. Also the SelectedIndexChanged
event is never hit. Why is this happening?

-----------------------------------
<asp:GridView ID="gvSearchResults" runat="server"
AutoGenerateColumns="false" AutoGenerateSelectButton="false"
GridLines="none" DataKeyNames="entity_uid" SelectedIndex="0"
OnRowDataBound="gvSearchResults_OnRowDataBound"
OnSelectedIndexChanged="gvSearchResults_SelectedIndexChanged" Font-
Size="x-Small" CellSpacing="1">
<Columns>

<asp:TemplateField>
<ItemTemplate>
<asp:LinkButton ID="lbDetail" runat="server"
CommandName="Select" Text="View Detail" />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate>
<asp:Label ID="lblRecordInfo" runat="server" />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate>
<asp:Image ID="imgPhoto" runat="server" />
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField ReadOnly="true" HeaderText="FName"
DataField="FName" HeaderStyle-Font-Bold="true" />
<asp:BoundField ReadOnly="true" HeaderText="LName"
DataField="LName" HeaderStyle-Font-Bold="true" />
<asp:BoundField ReadOnly="true" HeaderText="GradYear"
DataField="GradYearDegree" HeaderStyle-Font-Bold="true" />
<asp:BoundField ReadOnly="true" HeaderText="&nbsp;Cohort&nbsp;"
DataField="cohort" HeaderStyle-Font-Bold="true" />
<asp:BoundField ReadOnly="true" HeaderText="DegreePrgoram"
DataField="DegreeProgram" HeaderStyle-Font-Bold="true" />
<asp:TemplateField HeaderText="PrefEmail" HeaderStyle-Font-
Bold="true">
<ItemTemplate>
<asp:HyperLink ID="hplPrefEmail" runat="server"
ForeColor="darkBlue" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
<AlternatingRowStyle BackColor="white" />
<RowStyle BackColor="beige" />
</asp:GridView>
----------------------------------------------------------------

protected void Page_Load(object sender, EventArgs e)
{

if (!IsPostBack)
{
DataSet dsSearchResults =
SQLRoutines.SearchRecords(P);
Trace.Write("Count:",
dsSearchResults.Tables[0].Rows.Count.ToString());
gvSearchResults.DataSource = dsSearchResults;
gvSearchResults.DataBind();
}

}


protected void gvSearchResults_SelectedIndexChanged(object sender,
EventArgs e)
{
SelectedUID = (string)gvSearchResults.SelectedValue;
Trace.Write("SelectedIndexChanged", SelectedUID);
Server.Transfer("SearchResultsBio.asp", true);
}

Thanks,
Robert
Click to expand...
 
First, you have to create the objects early enough. The SelectedIndexChanged
event is not firing because the object doesn't exist yet. You have to call
your databinding code much earlier. You can try the OnInit event, or the
OnPreLoad event insteat. Page Load is just too late in the scheme of things
as it occurs after postback. You'll need to eliminate the test for postback,
the controls will need to be recreated each time.

--
Hope this helps,
Mark Fitzpatrick
Former Microsoft FrontPage MVP 199?-2006




I've got a gridview with BoundFields and TemplateFields and a
linkbutton with a CommandName="Select". When I click on this
linkbutton the TemplateField objects disappear on postback but the
BoundFields still have their data. Also the SelectedIndexChanged
event is never hit. Why is this happening?
Click to expand...
-----------------------------------
<asp:GridView ID="gvSearchResults" runat="server"
AutoGenerateColumns="false" AutoGenerateSelectButton="false"
GridLines="none" DataKeyNames="entity_uid" SelectedIndex="0"
OnRowDataBound="gvSearchResults_OnRowDataBound"
OnSelectedIndexChanged="gvSearchResults_SelectedIndexChanged" Font-
Size="x-Small" CellSpacing="1">
<Columns>
Click to expand...
<asp:TemplateField>
<ItemTemplate>
<asp:LinkButton ID="lbDetail" runat="server"
CommandName="Select" Text="View Detail" />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate>
<asp:Label ID="lblRecordInfo" runat="server" />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate>
<asp:Image ID="imgPhoto" runat="server" />
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField ReadOnly="true" HeaderText="FName"
DataField="FName" HeaderStyle-Font-Bold="true" />
<asp:BoundField ReadOnly="true" HeaderText="LName"
DataField="LName" HeaderStyle-Font-Bold="true" />
<asp:BoundField ReadOnly="true" HeaderText="GradYear"
DataField="GradYearDegree" HeaderStyle-Font-Bold="true" />
<asp:BoundField ReadOnly="true" HeaderText="&nbsp;Cohort&nbsp;"
DataField="cohort" HeaderStyle-Font-Bold="true" />
<asp:BoundField ReadOnly="true" HeaderText="DegreePrgoram"
DataField="DegreeProgram" HeaderStyle-Font-Bold="true" />
<asp:TemplateField HeaderText="PrefEmail" HeaderStyle-Font-
Bold="true">
<ItemTemplate>
<asp:HyperLink ID="hplPrefEmail" runat="server"
ForeColor="darkBlue" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
<AlternatingRowStyle BackColor="white" />
<RowStyle BackColor="beige" />
</asp:GridView>
----------------------------------------------------------------
Click to expand...
protected void Page_Load(object sender, EventArgs e)
{
Click to expand...
if (!IsPostBack)
{
DataSet dsSearchResults =
SQLRoutines.SearchRecords(P);
Trace.Write("Count:",
dsSearchResults.Tables[0].Rows.Count.ToString());
gvSearchResults.DataSource = dsSearchResults;
gvSearchResults.DataBind();
}
}
Click to expand...

protected void gvSearchResults_SelectedIndexChanged(object sender,
EventArgs e)
{
SelectedUID = (string)gvSearchResults.SelectedValue;
Trace.Write("SelectedIndexChanged", SelectedUID);
Server.Transfer("SearchResultsBio.asp", true);
}
Click to expand...
Thanks,
Robert- Hide quoted text -
Click to expand...

- Show quoted text -
Click to expand...

Mark,

Thanks I got it to work. I had been dynamically removing columns by
doing
code like the following:

gvSearchResults.Columns.Remove(gvSearchResults.Columns[51]);

before doing the databind. I moved this logic to after the databind
and the SelectedIndexChanged event fired and the page works now. I
also decided to do

gvSearchResults.Columns[51].Visible = false;

which is easier to work with.

Thanks!
Happy Monday,
Robert
 
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