Binding controls dynamically to PlaceHolder in asp:DataList - c#

I can't seem to figure this one out but I'm trying to add a user control to a DataList at runtime (because the actual control type can differ). So if I hard code the control reference in the markup like this it works:
<asp:DataList ID="myDL" runat="server" RepeatDirection="Horizontal" RepeatColumns="3" OnItemDataBound="myDL_Item_Bound">
<ItemTemplate>
<prefix:MyControl ID="myControl1" runat="server" />
</ItemTemplate>
</asp:DataList>
But if I try to add it programmatically to a placeholder, it does not render the user controls (just empty td tags):
<asp:DataList ID="myDL" runat="server" RepeatDirection="Horizontal" RepeatColumns="3" OnItemDataBound="myDL_Item_Bound">
<ItemTemplate>
<asp:PlaceHolder ID="ph" runat="server">
</asp:PlaceHolder>
</ItemTemplate>
</asp:DataList>
protected void myDL_Item_Bound(Object sender, DataListItemEventArgs e) {
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem) {
PlaceHolder ph = (PlaceHolder)e.Item.FindControl("ph");
if (ph != null) {
MyControl ctrl = new MyControl();
ctrl.SomeProp = "xyz";
ph.Controls.Add(ctrl);
}
else {
MyControl ctrl = (MyControl)e.Item.FindControl("myControl1");
ctrl.SomeProp = "xyz";
}
}
}
what am I missing?

You are not adding the control to the page. You need to add it:
Control ctrl = (Control)Page.LoadControl("MyControl.ascx");
// MyControl ctrl = new MyControl();
ctrl.SomeProp = "xyz";
ph.Controls.Add(ctrl);

Related

Using Datalist Items within a nested repeater

I have this code for a blog which is nesting a repeater control within a datalist.
I'm trying to assign the alt tags of the repeater control images to be the title of the post coming through the datalist however, it will not let me though this because it has a different data source.
Any suggestions as to how I can do this?
Here's my code:
<asp:DataList runat="server" ID="DataList1" ItemStyle-CssClass="row1BackgroundBlock" OnItemDataBound="DataList1_ItemDataBound" >
<ItemTemplate>
<!-- <%#Eval("PostId")%> post -->
<div class="dateBox"><asp:Label ID="Label1" runat="server" ForeColor="#ffffff" Font-Bold="False" Text='<%# Eval("PublicationDate","{0:dd/MM/yyyy}") %>' CssClass="postmetadata"></asp:Label></div>
<div class="roundPanelStack">
<h2><asp:HyperLink ID="HyperLink1" runat="server" NavigateUrl='<%# Engine2010.Blog.BlogLinksManager.GetFullPostsLinks((int)Eval("PostId"), (object)Eval("FURL")) %>'><%# Eval("Title") %></asp:HyperLink></h2>
<ul><li class="postBy">Posted in <%#Eval("CategoryName")%> by <%#Eval("Author")%></li><li class="last">{<%# Engine2010.Blog.PostComment.GetAllByPostId(int.Parse(Eval("PostId").ToString()), 766).Rows.Count.ToString()%> comments}</li></ul>
<div class="thumbWindow">
<div style="border:7px solid #fff;display:block;height:95px;left:1px;position:absolute;top:1px;width:95px;z-index:5;"></div>
<asp:Repeater ID="repImgs" runat="server">
<ItemTemplate>
<img class="thumb_view" src="/uploads/images/Blog/<%# Eval("Directory").ToString().Substring(Eval("Directory").ToString().LastIndexOf("\\")+1) %>/<%# Eval("Name") %>" alt="" border="0" width="143" height="143" />
</ItemTemplate>
</asp:Repeater>
<asp:PlaceHolder ID="PlaceHolder1" runat="server" Visible="false">
<img src="/includes/images/general/default.jpg" alt="Default" border="0" width="110" height="110" />
</asp:PlaceHolder>
</div>
<p>
<asp:Label ID="Label2" runat="server" Text='<%#CommonFunctions.Remove_HTML_Tags(Eval("Description").ToString()) %>' CssClass="entry"></asp:Label>
</p>
<div class="linksMore">
<asp:HyperLink ID="FullStoryLink" runat="server" NavigateUrl='<%# Engine2010.Blog.BlogLinksManager.GetFullPostsLinks((int)Eval("PostId"), (object)Eval("FURL")) %>' CssClass="fullstory">Read Full Post</asp:HyperLink><a class="spacer"> // </a><asp:HyperLink ID="CommentsLink" runat="server" NavigateUrl='<%# Engine2010.Blog.BlogLinksManager.GetFullPostsLinks((int)Eval("PostId"), (object)Eval("FURL")) + "#comment" %>' CssClass="comments">Comment</asp:HyperLink>
</div>
</div>
<!-- /first post -->
</ItemTemplate>
</asp:DataList>
Backend:
protected void DataList1_ItemDataBound(object sender, DataListItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
Repeater repImages = (Repeater)e.Item.FindControl("repImgs"); // Child repeater with images for room
string amenText = ((DataRowView)e.Item.DataItem).Row.ItemArray[7].ToString();
DirectoryInfo folderBr = new DirectoryInfo(Server.MapPath("~/uploads/images/Blog/") + amenText);
// List<Engine2010.ImageObj> imageObjs = folderBr.GetImagesInPath();
if (folderBr.Exists)
{
repImages.DataSource = folderBr.GetFiles("thumb*.*"); // Bind room images to child repeater
repImages.DataBind();
if (repImages.Items.Count == 0)
{
PlaceHolder placeholder1 = (PlaceHolder)e.Item.FindControl("PlaceHolder1");
placeholder1.Visible = true;
}
}
else {
PlaceHolder placeholder1 = (PlaceHolder)e.Item.FindControl("PlaceHolder1");
placeholder1.Visible = true;
}
}
}
In the ItemDataBound event of your DataList1 after binding repImages repater control, iterate through each item by using RepeaterItem and then find your img control and assign title in alt tag like this -
protected void DataList1_ItemDataBound(object sender, DataListItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
Repeater repImages = (Repeater)e.Item.FindControl("repImgs");
string amenText = ((DataRowView)e.Item.DataItem).Row.ItemArray[7].ToString();
DirectoryInfo folderBr = new DirectoryInfo(Server.MapPath("~/uploads/images/Blog/") + amenText);
if (folderBr.Exists)
{
repImages.DataSource = folderBr.GetFiles("thumb*.*"); // Bind room images to child repeater
repImages.DataBind();
if (repImages.Items.Count == 0)
{
PlaceHolder placeholder1 = (PlaceHolder)e.Item.FindControl("PlaceHolder1");
placeholder1.Visible = true;
}
// Iterate thru each item of your child repeate control.
foreach (RepeaterItem repeaterItem in repImages.Items)
{
if (repeaterItem.ItemType == ListItemType.Item ||
repeaterItem.ItemType == ListItemType.AlternatingItem)
{
((HtmlImage)(repeaterItem.FindControl("imgId"))).Alt = amenText; // Assume amenText is the title of your post
}
}
}
else
{
PlaceHolder placeholder1 = (PlaceHolder)e.Item.FindControl("PlaceHolder1");
placeholder1.Visible = true;
}
}
}
good luck...

How to keep CheckBox checked state in DataList after postback?

I'm creating a really simple "tag cloud" function for a project database. I want the user to be able to check various tags and, then, with an autopostback on the checked box(es), display the associated projects that have those tags.
It works, but the checkboxes are resetting after postback. I want the checkboxes to remain checked (or unchecked, as the case may be) so the user can select multiple tags.
I've searched and seen that some say to put the databinding event within an if(!isPostBack). I've tried that, but it doesn't seem to matter.
aspx code:
<asp:DataList ID="TagDataList" runat="server" OnDataBinding="databindthesucker" DataKeyField="TagName">
<ItemTemplate>
<asp:CheckBox AutoPostBack="true" ID="TagCheckbox" runat="server" Text='<%#Eval ("dZTagName") %>' />
<asp:HiddenField ID="TagNameHidden" runat="server" Value='<%#Eval ("dZTagName") %>'/><br />
</ItemTemplate>
</asp:DataList>
<asp:DataList ID="ProjectDataList" runat="server" DataKeyField="projectID">
<ItemTemplate>
<asp:HyperLink ID="ProjectLink" runat="server" NavigateUrl='<%# "/Project/Default.aspx?PID=" + Eval ("projectID") %>' Text='<%# Eval ("projectID") + ": " + Eval ("projectName") %>'> </asp:HyperLink><br />
</ItemTemplate>
</asp:DataList>
and then the cs...
protected void Page_Load(object sender, EventArgs e)
{
displaytags(sender, e);
}
protected void displaytags(object sender, EventArgs e)
{
var qrygettags = (from t in db.TagTables
select new { t.TagName }).Distinct().ToList();
TagDataList.DataSource = qrygettags;
TagDataList.DataBind();
CheckBox TagCheckbox = (CheckBox)TagDataList.Items[0].FindControl("TagCheckbox");
}
protected void databindthesucker(object sender, EventArgs e)
{
foreach (DataListItem item in TagDataList.Items)
{
if (item.ItemType == ListItemType.Item || item.ItemType == ListItemType.AlternatingItem)
{
CheckBox TagCheckbox = (CheckBox)item.FindControl("TagCheckbox");
HiddenField TagNameHidden = (HiddenField)item.FindControl("TagNameHidden");
string Tagstring = TagNameHidden.Value.ToString();
if (TagCheckbox.Checked)
{
var qrygetprojects = (from p in db.projects
join pt in db.TagTables on p.projectID equals pt.projectID
where pt.TagName == Tagstring
select new
{
pt.projectID,
p.projectName
}).ToList();
ProjectDataList.DataSource = qrygetprojects;
ProjectDataList.DataBind();
}
}
}
}
Any ideas?

How to Add UserControl Conditionally to Repeater Control?

I want to know how to Add a UserControl Conditionally to a Repeater Control. I have tried to add it to the placeholder which is in Repeater Control but unable to load the usercontrol. This following code doesn't work.
<asp:Repeater ID="ResultsRepeater" runat="server">
<HeaderTemplate></HeaderTemplate>
<ItemTemplate>
<div>
<asp:PlaceHolder ID="PlaceHolder1" runat="server">
</asp:PlaceHolder>
</div>
</ItemTemplate>
</asp:Repeater>
public void GetStatus(int i)
{
UserControl uc = new UserControl();
if(i==1)
{
uc = LoadControl("DraftList.ascx") as UserControl;
}
else if(i==2)
{
uc = LoadControl("FinalList.ascx") as UserControl;
}
PlaceHolder p1 = (PlaceHolder)ResultsRepeater.Items[0].FindControl("PlaceHolder1");
p1.Controls.Add(uc);
}
Is there some reason that you don't want to just handle all of this in the aspx? That would be the simplest and cleanest option:
<asp:Repeater runat="server" ID="ResultsRepeater">
<ItemTemplate>
<uc1:DraftList ID="DraftList1" runat="server" Visible='<%# ((int)Eval("Status") == 1)%>' />
<uc2:FinalList ID="FinalList1" runat="server" Visible='<%# ((int)Eval("Status") == 2)%>' />
</ItemTemplate>
</asp:Repeater>
If a control is not visible, (i.e., Visible=false) then no markup is rendered, so coding in this fashion would not create any more work for the server or the client browser, while having the benefit of being much easier to read and providing user control properties at design-time.
You would just need to make sure to register your controls at the top of the page:
<%# Register src="DraftList.ascx" tagname="DraftList" tagprefix="uc1" %>
<%# Register src="FinalList.ascx" tagname="FinalList" tagprefix="uc2" %>
Why don't you try adding it within the repeaters ItemDataBound event? I.e.,
<asp:Repeater ID="ResultsRepeater" OnItemDataBound="ResultsRepeater_ItemDataBound" runat="server">
<HeaderTemplate></HeaderTemplate>
<ItemTemplate>
<div>
<asp:PlaceHolder ID="PlaceHolder1" runat="server">
</asp:PlaceHolder>
</div>
</ItemTemplate>
</asp:Repeater>
and in the code behind
protected void ResultsRepeater_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
Panel PlaceHolder1 = (Panel)e.Item.FindControl("PlaceHolder1");
// declare/obtain the value of i given the DataItem
// e.g.,
int i = ((int)e.Item.DataItem); // or however you're getting i
if (i == 1)
{
var uc = LoadControl("~/DraftList.ascx");
PlaceHolder1.Controls.Add(uc);
}
else if (i == 2)
{
var uc = LoadControl("~/FinalList.ascx");
PlaceHolder1.Controls.Add(uc);
}
}
}
Judging by your last comment (to the question) you might need to also make sure you've attached and bound your datasource to the repeater as well. I.e.,
ResultsRepeater.DataSource = dataSource; //whatever your datasource is e.g., datatable, IEnumerable list etc
ResultsRepeater.DataBind();

Accessing a control within a Repeater

Lets say I have the following:
<asp:Repeater ID="repSubItems" runat="server" DataSource="<%# SubItems %>" >
<ItemTemplate>
<sc:FieldRenderer ID="FieldRenderer1"
FieldName="BlurbSpot_Content_SubHeading"
runat="server"
Item="<%# Container.DataItem as Sitecore.Data.Items.Item %>" />
</ItemTemplate>
</asp:Repeater>
I want to in code behind be able to do:
FieldRenderer1.Style["Width"] = MyCoolWidth;
But within the Repeater I cannot access the FieldRenderer1 control.
You will need to handle the ItemDataBound event of the repSubItems repeater. Example:
protected void repSubItems_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
var fieldRenderer1 = e.Item.FindControl("FieldRenderer1") as Sitecore.Web.UI.WebControls.FieldRenderer;
if (fieldRenderer1 != null)
{
fieldRenderer1.Style["Width"] = MyCoolWidth;
}
}
}
You need to find the row your are looking for specifically in the Repeater and then find the control. Here is an example that can do it for all items in your Repeater:
// repeater item
foreach (Control cr in repSubItems.Controls)
{
// assuming this is your templated control name and not the final output name
FieldRenderer founcControl = cr.FindControl("FieldRenderer1") as FieldRenderer;
founcControl .Style["Width"] = MyCoolWidth;
}
The better way to do this would be to implement the OnDataBinding for your control specifically because then you have no searching to do:
<sc:FieldRenderer ID="FieldRenderer1" FieldName="BlurbSpot_Content_SubHeading"
runat="server" Item="<%# Container.DataItem as Sitecore.Data.Items.Item %>"
OnDataBinding="FieldRenderer1_DataBinding" />
protected void FieldRenderer1_DataBinding(object sender, System.EventArgs e)
{
FieldRenderer rend = (FieldRenderer)(sender);
// you can do whatever you want to rend at this point and it is scoped to ONLY
// the control so you never have to search for it.
rend.Style["Width"] = MyCoolWidth;
}

Hide an element in ASP.net based on an if inside a Repeater

I know how to use a simple If statement wrapped in the <%# tags to hide something, but I don't know how to do it in a repeater when I need to access Container.DataItem, as in I need the dataItem currently being 'repeated'
eg
if (CurrentValidationMessage.Link != "")
{
show a hyperlink
}
Markup:
<asp:Repeater ID="repValidationResults" runat="server">
<HeaderTemplate>
</HeaderTemplate>
<ItemTemplate>
<a href='<%# ((MttImportValidationMessage)Container.DataItem).EditLink %>'> Link to erroneous Milestone </a>
<%# ((MttImportValidationMessage)Container.DataItem).Message %>
<br />
</ItemTemplate>
</asp:Repeater>
It might be more maintainable if you just tagged the controls in the repeater with id's and runat='server' and reference the DataItem in the ItemDataBound event by using e.Item.DataItem.
Then use e.Item.FindControl to reference your controls in the ItemTemplate and perform your logic.
protected void repeater_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.AlternatingItem || e.Item.ItemType == ListItemType.Item)
{
Domain.Employee employee = (Domain.Employee)e.Item.DataItem;
Control myControl = (Control)e.Item.FindControl("controlID");
//Perform logic
}
}
use ItemDataBound Event with repeater, and make the "a" tag with a runat="server" property and ID
protected void repValidationResults_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
RepeaterItem item = e.Item;
if (item.ItemType == ListItemType.AlternatingItem || item.ItemType == ListItemType.Item)
{
HyperLink link = (HyperLink) item.FindControl("link");
//Do all your logic here :)
}
}
MarkUp:
<asp:Repeater ID="repValidationResults" runat="server">
<HeaderTemplate>
</HeaderTemplate>
<ItemTemplate>
<a runat="server" ID="link"> Link to erroneous Milestone </a>
<%# ((MttImportValidationMessage)Container.DataItem).Message %>
<br />
</ItemTemplate>
</asp:Repeater>

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