Find Linkbutton in Repeater Itemtemplate when on page load - asp.net

I'm using a LinkButton in Repeater ItemTemplate but if my LinkButton is NULL then I don't want to show this Linkbutton. Can I control this LinkButton on Page Load?
<asp:Repeater ID="rptSlider" runat="server" >
<ItemTemplate>
<li>
.....
<asp:LinkButton ID="lb_url" PostBackUrl='<%#Eval("button_url") %>' runat="server">Go</asp:LinkButton>
...
</li>
</ItemTemplate>

Try this way in page-load event
LinkButton linkButton= (LinkButton)Repeater1.Items[0].FindControl("lb_url");
linkButton.Visible = false;
but I will suggest to use ItemDataBound event to set visibility of link-button.
protected void repeater_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item ||
e.Item.ItemType == ListItemType.AlternatingItem)
{
var linkButton= e.Item.FindControl("lb_url") as LinkButton;
// set link-button visibility
}
}

You may check the same under ItemCommand. Please check whether the following code works or not.
protected void Repeater1_ItemCommand(object source, RepeaterCommandEventArgs e)
{
string url=((LinkButton)e.CommandSource).Text;
if (string.IsNullOrEmpty(url))
((LinkButton)e.CommandSource).Visible=false;
else
((LinkButton)e.CommandSource).Visible=true;
}

Related

How to retrieve a button inside a ListView which is inside a Repeater

I want to access the button btn3 inside a ListView. The ListView itself is in the ItemTemplate of a Repeater.
<asp:Repeater runat="server" ID="rep1">
<ItemTemplate>
<asp:ListView ID="ListView1" runat="server" DataSourceID="SqlDataSource1">
...
<asp:Button ID="btn3" runat="server" Text='<%#Eval("likes").ToString()%>'/>
...
</asp:ListView>
</ItemTemplate>
</asp:Repeater>
When I try to access btn3 in the ItemDataBound event of the Repeater, the returned value is null:
protected void repeater_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
Button btn1 = (Button)e.Item.FindControl("Btn3"); // btn1 is null
}
}
You can set the ItemDataBound event handler of the ListView:
<asp:Repeater runat="server" ID="rep1">
<ItemTemplate>
<asp:ListView ID="ListView1" runat="server" OnItemDataBound="ListView1_ItemDataBound" DataSourceID="SqlDataSource1">
...
</asp:ListView>
</ItemTemplate>
</asp:Repeater>
And retrieve the button in code-behind:
protected void ListView1_ItemDataBound(object sender, ListViewItemEventArgs e)
{
if (e.Item.ItemType == ListViewItemType.DataItem)
{
Button btn3 = e.Item.FindControl("btn3") as Button;
...
}
}
If you want to do it in the Repeater ItemDataBound event handler (but I am not sure if the ListView is populated at that point):
protected void repeater_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
ListView ListView1 = e.Item.FindControl("ListView1") as ListView;
List<Button> buttons = new List<Button>();
foreach (ListViewItem lvItem in ListView1.Items)
{
buttons.Add(lvItem.FindControl("Btn3") as Button);
}
// Use the list of buttons
...
}
}

Repeater with Buttons doesn't fire OnItemCommand even when DataBind doesn't happen when IsPostBack is true

I've got an image button in a Repeater, which is in a User Control, and I can't get the OnItemCommand event to fire when I click it. It always gives the error: "... Invalid postback or callback argument. Event validation is enabled using ..."
When I change the image button to a link button, it doesn't give me the error, but it still doesn't fire the OnItemCommand function.
I found some other relevant answers (such as How to process events from Buttons inside Repeaters? And what's this EnableEventValidation thing?) but they all say, "Make sure you're data-binding your repeater inside of a if(!Page.IsPostBack) block." I have done that, but it didn't make a difference.
Here's the markup for the repeater:
<asp:Repeater ID="rptExpenses" OnItemDataBound="rptExpenses_ItemDataBound" OnItemCommand="Button_Command" runat="server" >
<ItemTemplate>
<asp:ImageButton ID="ibDelete" ImageUrl="~/Images/delete.png" CommandName="Delete" runat="server" />
</ItemTemplate>
</asp:Repeater>
Here's some exerpts from the code-behind
protected void Page_Load(object sender, EventArgs e) {
if (!IsPostBack) {
rptExpenses.DataSource = ExpenseIds;
rptExpenses.DataBind();
}
}
protected void rptExpenses_ItemDataBound(object sender, RepeaterItemEventArgs e) {
if ((e.Item.ItemType == ListItemType.Item) || (e.Item.ItemType == ListItemType.AlternatingItem)) {
var ibDelete = (ImageButton)e.Item.FindControl("ibDelete");
ibDelete.CommandArgument = e.Item.DataItem.ToString();
}
}
protected void Button_Command(object sender, EventArgs e) {
var btn = (IButtonControl)sender;
switch (btn.CommandName) {
case "Delete":
//delete it
break;
}
}
Try using this code instead:
<asp:Repeater ID="rptExpenses" runat="server">
<ItemTemplate>
<asp:ImageButton ID="ibRemove" ImageUrl="~/Images/delete.png" runat="server"
CommandName="Remove"
CommandArgument='<%# Container.DataItem %>'
OnCommand="ibRemove_Click"/>
</ItemTemplate>
</asp:Repeater>
And this in the code behind:
protected void Page_Load(object sender, EventArgs e) {
if (!IsPostBack) {
rptExpenses.DataSource = ExpenseIds;
rptExpenses.DataBind();
}
}
protected void ibRemove_Click(object sender, CommandEventArgs e)
{
var btn = (IButtonControl)sender;
switch (btn.CommandName)
{
case "Remove":
//delete it, use btn.CommandArgument to find id to remove
break;
}
}
If you still receive the ... Invalid postback or callback argument. Event validation is enabled using ... error, it most likely means that you are somewhere re-binding the repeater before the ibRemove_Click(...) event is raised.
I found the reason why this was happening in the answer to this question: Why ItemCommand doesn't fired on My Repeater
Turns out that for some reason the Page's DataBind function was invalidating the repeater's controls without passing through the repeater's OnItemDataBound function a second time.

Respond to Button Events inside Repeater ItemTemplate

so i have removed the datasouce and just have DataBind() then my page is still blowing and refreshing the page and not in a EDIT mode.
what i am trying to do is when the user click on Edit button then make it inline editing the repeater row.
END UPDATE
onItemCommand i have added DataBind()
rpt.DataSource = mydatasource;
rpt.DataBind();
after i do that my page is not in edit mode and it blow away and everyting is refreshed
i have on page_load
if (!IsPostBack)
{
rpt.DataSource = mydatasource;
rpt.DataBind();
}
end update
I've used repeaters many times without problems but something is going on here. I have a repeater and I'm subscribing to the itemDatabound event, But when i click the button (which is a linkbutton inside my repeater itemtemplate) it does not go to the ItemDataBound
<asp:Repeater ID="rpt" runat="server" OnItemCommand="rpt_OnItemCommand" OnItemDataBound="rpt_OnItemDataBound">
<ItemTemplate>
<li>
<asp:Label ID="Label" runat="server" />
<asp:LinkButton ID="LinkButton1" runat="server" CommandName="edit" CommandArgument='<%# Eval("MyID") %>'
Text='<%# Eval("Title") %>' />
</li>
</ItemTemplate>
</asp:Repeater>
protected void rpt_OnItemCommand(object source, RepeaterCommandEventArgs e)
{
if (e.CommandName == "delete")
{
//Data.Contacts.RemoveAt(e.Item.ItemIndex);
}
else if (e.CommandName == "edit")
{
EditIndex = e.Item.ItemIndex;
}
else if (e.CommandName == "save")
{
//
}
}
protected void rpt_OnItemDataBound(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
if (e.Item.ItemIndex == EditIndex)
{
// never come to this line.... after the user click on LinkButton
}
}
}
Don't know if this helps but you must call DataBind() in order for for the OnItemDataBound event to fire. Also my guess is you are trying to set the EditIndex in the OnItemCommand and then use the value in the OnDataBind event. The events fire in the order OnItemDataBound then OnItemCommand so the EditIndex wouldn't be correct anyway in that situation.
Add rpt.DataBind to the OnItemCommand. This workded when I tried it from your code, NOTE that you will be binding twice if you aren't using !IsPostBack for original data bind.
rpt.DataSource = strings;
if (!IsPostBack)
{
rpt.DataBind();
}
protected void rpt_OnItemCommand(object source, RepeaterCommandEventArgs e)
{
if (e.CommandName == "delete")
{
//Data.Contacts.RemoveAt(e.Item.ItemIndex);
}
else if (e.CommandName == "edit")
{
EditIndex = e.Item.ItemIndex;
}
else if (e.CommandName == "save")
{
//
}
rpt.DataBind();
}
You must change your rpt_OnItemCommand function.
protected void rpt_OnItemCommand(object source, RepeaterCommandEventArgs e)
{
if (e.CommandName == "delete")
{
//Data.Contacts.RemoveAt(e.Item.ItemIndex);
}
else if (e.CommandName == "edit")
{
EditIndex = e.Item.ItemIndex;
}
else if (e.CommandName == "save")
{
//
}
else if (e.CommandName == "Complete")
{
// your function goes here
}
}
Why do you think that the ItemDataBound is raised when you click your LinkButton? ItemDataBound is only fired when Repeater.DataBind() is called.
Actually the repeater's ItemCommand event is raised instead.
I'm a little confused, but from the example above it looks like you've got it backwards. The button click would never fire the ItemDataBound event. The ItemDataBound event is only called after each item is bound to the repeater.
The button click should fire the ItemCommand event however, and if that's not happening I would check to make sure you've actually assigned the ItemCommand handler, and also make sure that the command name is valid.
On a side note, this behavior can also happen when the repeater is bound at every postback. Make sure that you're binding the repeater when !Page.IsPostBack.

RadioButtonList Inside Repeater OnSelectedIndexChanged Not Firing

I have a RadioButtonList inside a Repeater. I have AutoPostback set to "true" and the OnSelectedIndexChanged defined. When I selected a different radiobutton in my list the page does postback, but my defined OnSelectedIndexChanged event is not catching or firing. Not sure what I am missing. Here is my markup and codebehind:
Use the repeater's itemcreated event to bind your eventhandler:
protected void Repeater!_ItemCreated(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.AlternatingItem || e.Item.ItemType == ListItemType.Item)
{
e.item.FindControl("TaskRadioButtonList").SelectedIndexChanged += new EventHandler(TaskRadioButtonList_OnSelectedIndexChanged);
}
}

Why is the footer-item not included in Repeater.Items?

I need to get a value from a textbox inside a FooterTemplate in the OnClick event of a button. My first thought was to loop through the items-property on my repeater, but as you can see in this sample, it only includes the actual databound items, not the footer-item.
ASPX:
<asp:Repeater ID="Repeater1" runat="server">
<ItemTemplate>
Item<br />
</ItemTemplate>
<FooterTemplate>
Footer<br />
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
</FooterTemplate>
</asp:Repeater>
<asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />
Code-behind.cs:
protected void Page_Load(object sender, EventArgs e)
{
ListItemCollection items = new ListItemCollection();
items.Add("value1");
items.Add("value2");
Repeater1.DataSource = items;
Repeater1.DataBind();
}
protected void Button1_Click(object sender, EventArgs e)
{
System.Diagnostics.Debug.WriteLine(Repeater1.Items.Count);
}
This code will only output "2" as the count, so how do I get to reference my textbox inside the footertemplate?
From the MSDN documentation, the Items is simply a set of RepeaterItems based off the DataSource that you are binding to and does not include items in the Header or FooterTemplates.
If you want to reference the textbox, you can get a reference on ItemDataBound event from the repeater where you can test for the footer.
E.g.
private void Repeater_ItemDataBound(Object Sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Footer)
{
TextBox textBox = e.Item.FindControl("TextBox1") as TextBox;
}
}
You can find controls in the repeater. That will give you all the controls in the repeater (RepeaterItems collection). Now you can do something like this:
RepeaterItem footerItem=null;
foreach(Control cnt in Repeater1.Controls)
{
if(cnt.GetType() == typeof(RepeaterItem) && ((RepeaterItem)cnt).ItemType == ListItemType.Footer)
{
footerItem = cnt;
break;
}
}
The footer should be the last child control of the repeater so you can do something like..
RepeaterItem riFooter = Repeater1.Controls[Repeater1.Controls.Count - 1] as RepeaterItem;
if (riFooter != null && riFooter.ItemType == ListItemType.Footer) {
TextBox TextBox1 = riFooter.FindControl("TextBox1") as TextBox;
if (TextBox1 != null) {
TextBox1.Text = "Test";
}
}

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