<ItemTemplate>
<asp:Label runat="server"><%#DataBinder.Eval(Container.DataItem, "Question")%></asp:Label>
<asp:DropDownList runat="server" id="<%#DataBinder.Eval(Container.DataItem, "QuestionID")%>">>
<asp:ListItem value="1" text="Yes" />
<asp:ListItem value="0" text="No" />
</asp:DropDownList>
<ItemTemplate>
This is roughly what I'm trying to do. Obviously, the implementation is faulty, but I can't find any information on how I'd go about this in practice. Any help is appreciated.
Edit: What I'm trying to do exactly is add a DropDownList for each item in this Repeater, and upon submission of the form, use the ID's of each Yes/No answer to input into a database. The SqlDataReader that I'm using has two fields: The question content and the questionID.
I think you'd be better off using the built in support for IDs inside a Repeater. If the goal is to assign it an ID to make it easy to find the proper control after the data has been bound you might try something like this:
<asp:Repeater ID="Repeater1" runat="server>
<ItemTemplate>
<asp:Label ID="QuestionID" Visible="False" Runat="server"><%#DataBinder.Eval(Container.DataItem, "FieldContent")%></asp:Label>
<asp:DropDownList ID="MyDropDownList" Runat="server"></asp:DropDownList>
</ItemTemplate>
</asp:Repeater>
Then, in your code you can loop through the items in the Repeater until you find the label you're looking for:
foreach (RepeaterItem curItem in Repeater1.Items)
{
// Due to the way a Repeater works, these two controls are linked together. The questionID
// label that is found is in the same RepeaterItem as the DropDownList (and any other controls
// you might find using curRow.FindControl)
var questionID = curRow.FindControl("QuestionID") as Label;
var myDropDownList = curRow.FindControl("MyDropDownList") as DropDownList;
}
A Repeater basically consists of a collection of RepeaterItems. The RepeaterItems are specified using the ItemTemplate tag. Each RepeaterItem has its own set of controls that are, by the very nature of a Repeater, associated with each other.
Say you're pulling the Repeater data from a database. Each Repeater item represents data from an individual row in the query results. So if you assign the QuestionID to a label and the QuestionName to a DropDownList, the ID in the label would match up with the name in drop down.
Could you remove the control from the markup file, and hook the repeater's onItemDataBound event. In that event, you should be able to create the dropdown control "manually", assigning whatever ID you want.
Related
I have a repeater that contains a few controls and I want to set their ID's based on the IDs from database.
The datasource of the repeater is a list so basicly I want to do something like this in code behind, in repeater_ItemDataBound():
var myControl = e.Item.FindControl("controlID");
myControl.ClientIDMode = ClientIDMode.Static;
myControl.ID = e.Item.DataItem("ID"); //but I can't access the ID property, so here's my problem.
considering that I declared my repeater something like:
<asp:Repeater ID="repeater" runat="server">
<ItemTemplate>
<div class="someClass">
<asp:Label ID="controlID" runat="server"><%# Eval("Name")%></asp:Label>
<!-- list of other controls -->
</div>
</ItemTemplate>
</asp:Repeater>
Don't change ID's of controls that were already created with a different ID. That could cause nasty errors. Instead use the right ID in the first place. Or use whatever ID you use and assign the identifier to a different property like CommandArgument if it's a Button, Value if it's a HiddenField or Text if it's an (invisible) TextBox or Label.
So in this case you could use another control to store the ID:
<asp:HiddenField ID="hiddenID" runat="server" Value='<%# Eval("ID")%>' />
<asp:Label ID="lblName" runat="server"><%# Eval("Name")%></asp:Label>
Now, if you need the ID of the current item and you have the reference of the label or another control in that repeater-item:
var item = (RepeaterItem) lblName.NamingContainer;
HiddenField hiddenID = (HiddenField) item.FindControl("hiddenID");
string id = hiddenID.Value;
hi I have this gridview like this.
<asp:DropDownList ID="triggerDropDown" runat="server" AutoPostBack="true" onselectedindexchanged="triggerDropDown_SelectedIndexChanged">
<asp:GridView ID="myGridView" run="server">
<Columns>
<asp:TemplateField HeaderText="Column 1">
<ItemTemplate>
<asp:DropDownList ID="myDropDown1" runat="server" />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Column 2">
<ItemTemplate>
<asp:DropDownList ID="myDropDown2" runat="server" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
now, when I change my triggerDropDown I want to change also all of the DropDowns inside Column 1 how can I do that?
protected void triggerDropDown_SelectedIndexChanged(object sender, EventArgs e)
{
// what should I do here?
}
Inside your event method you should access the DropDownList that resides within each row of the GridView. Doing this you can bind each DropDownList to whatever data you want.
This link shows you how to do that:
http://www.velocityreviews.com/forums/t191319-need-help-with-accessing-a-control-within-a-template-field.html
Basically:
Iterate over each row of your GridView;
Find the DropDownList control with something like:
DropDownList mddl = GridView.Rows[2].FindControl("myDropDown1");
Bind new data to mddl.
The gridview is very likely not what you want here. The way to change the value of a control contained in a row is usually through grabbing a handle to the desired control using e.Item.FindControl() from within the ItemDataBound event of the gridview.
The problem with your approach is that you're wanting a control outside of the gridview (triggerDropDown) to interact with a single row of the gridview. Do you want the first row, first column, last row, first column or first column for each of the items in the grid? It's probably better you take the target of your trigger dropdown and place it outside of the gridview and deal with it directly.
If you really intend to change items in a row in the grid consider doing so in the ItemDataBound event of the gridview and you'll find lots of examples out there.
Actually I can use GridViewRow :) I just have to find the GridViewControl and get its Rows attribute which is a GridViewRow and now I can do a foreach of each row.
foreach (GridViewRow gridViewRow in (this.FindControl("myGridView") as GridView).Rows)
{
// I can see all elements of my row here as if I am traversing on GridViewEvents
}
I have a asp.net repeater control in a aspx page, with runat="server" and an id set, however for some reason i can't access its ID from code behind (I can access the id of the asp:detaislview control it sits in though). So instead in the page_load method I am doing the following:
Repeater repeater = (Repeater)PromotionSitesDetailsView.FindControl("estateRepeater");
repeater.DataSource = estateList;
However when run, an error comes up saying the repeater is null! All I want to do is set the datasource of this repeater to a List object. Any ideas?
You said the Repeater sits inside a DataList. The DataList is, itself, a kind of repeater - the controls inside of it don't exist until the DataList is bound to a datasource, and the controls in the template are created once per item in the source. So if you bind the DataList to a source with 3 items, you will get 3 repeaters.
So it looks kind of like this:
Page
MyDataList
Item0
MyRepeater
Item1
MyRepeater
Item2
MyRepeater
So obviously MyDataList.FindControl("MyRepeater") can't work - which "MyRepeater" are we talking about? Since multiple controls cannot have the same ID, ASP.NET solves this by making the ID unique to something called a NamingContainer. Since the DataList repeats the same set of controls many times (once per item in the data source), each item in the DataList is a NamingContainer.
We need to find the NamingContainer we know holds the instance of MyRepeater that we want:
MyDataList.Items[0].FindControl("MyRepeater");
You can iterate over the items in the DataList after it has been bound (of course, before it has been bound it has no items). You can also operate on a given item in the DataList as that item is being created:
<asp:DataList OnItemDataBound="MyDataList_HandleItemDataBound" ... />
//this will get called once per item as it is created
void MyDataList_HandleItemDataBound(object sender, DataListItemEventArgs e)
{
//e.Item is the current item being databound
Repeater myRepeater = e.Item.FindControl("MyRepeater") as Repeater;
myRepeater.DataSource = //ds
myRepeater.DataBind();
}
You can do it without code-behind, simply by assigning the Repeater DataSource. Here is an example of a two level hierarchical menu:
<ul>
<asp:Repeater ID="ctlMenu" runat="server">
<ItemTemplate>
<li>
<asp:HyperLink runat="server"
NavigateUrl='<%#(Container.DataItem as MyPage).GetUrl()%>'
Text="<%# (Container.DataItem as MyPage).GetName() %>"></asp:HyperLink>
<ul>
<asp:Repeater runat="server" DataSource="<%# (Container.DataItem as MyPage).GetChildren() %>">
<ItemTemplate>
<li>
<asp:HyperLink runat="server"
NavigateUrl='<%#(Container.DataItem as MyPage).GetUrl()%>'
Text="<%# (Container.DataItem as MyPage).GetName() %>"></asp:HyperLink>
</li>
</ItemTemplate>
</asp:Repeater>
</ul>
</ItemTemplate>
</asp:Repeater>
</ul>
So in this gridview, there is a column for status and I want to have a drop down list with Pass, Pending, Fail appear when the edit button is clicked. These values are already in a table, so I need to somehow bind from this table to each ddl for every row.
Here is the column from the gridview. As you can see, I would like to just have a label showing when not in edit mode, and a ddl when the edit button is pressed
<asp:TemplateField HeaderText="During Production Status" SortExpression="DuringProductionStatus">
<EditItemTemplate>
<asp:DropDownList ID="ddlStatus" runat="server" datavaluefield="Name"
datatextfield="Name" DataSource="*What goes here?*"> />
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="lblStatus" runat="server"
Text='I don't understand how to get this from the ddl' />
</ItemTemplate>
</asp:TemplateField>
For clarity's sake, my table is named Status, and the database is named DirectImport
There's a few steps to go through here - none of them are particularly difficult, but they can be a bit fiddly (IMHO). The good news is once you've got this working once, it gets easier to do it again!
I'm assuming you've got a <asp:*DataSource> control on your page - my preference is for an ObjectDataSource but I don't think it matters, I think a SqlDataSource works equally well. I've never tried doing this with GridView.DataSource = MyDataSet in code-behind, so I don't know whether that would work or not, but my assumption is that it wouldn't as you wouldn't get the proper two-way binding that you want. This data source feeds your grid with your main data. The key point here is that your database query must return both the Status text field and the Status id.
So your gridview will now look something like:
<asp:objectdatasource runat="server" id="MainDataSource" ... />
<asp:gridview runat="server" id="MyGridView" DataSourceID="MainDataSource">
<Columns>
<asp:TemplateField HeaderText="During Production Status" SortExpression="DuringProductionStatus">
<ItemTemplate>
<asp:Label ID="lblStatus" runat="server"
Text="<%# Bind('Status') %>" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:gridview>
The Text="<%# Bind('Status') %>" is the bit you're missing to get the status text into the grid.
Now add a second data source into your markup that reads in the set of values from the Status table.
<asp:objectdatasource runat="server" id="StatusObjectDataSource" ... />
And add the EditItemTemplate into the GridView, which is bound to the Status DataSource.
<EditItemTemplate>
<asp:DropDownList ID="ddlStatus" runat="server" datavaluefield="StatusID"
datatextfield="Status" DataSourceID="StatusObjectDataSource"
SelectedValue="<%# Bind('StatusId') %>" />
</EditItemTemplate>
The SelectedValue="<%# Bind('StatusId') %>" is what connects up the two datasets so that when you flip a row into Edit mode, the dropdownlist has the correct item already selected, and when you then save it you've got the Status ID to put into your database.
And you're done.
I have used the RowDataBound event. Here is a small code snippet. HTH
you would have an ItemTemplate in your aspx/ascx
<asp:TemplateField HeaderText="Column Headings">
<ItemTemplate>
<asp:DropDownList ID="ddlName" runat="server" Width="150"></asp:DropDownList>
</ItemTemplate>
</asp:TemplateField>
and in your code behind, you will have
protected void grdDataMap_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
DropDownList ddl = (DropDownList)e.Row.FindControl("ddlName");
ddl.DataSource = someList;//the source of your dropdown
ddl.DataBind();
}
}
so when you bind your grid with grdDataMap.Databind (assuming your grid id is grdDataMap), row databound event will be called for each row (including header/footer, and thats the reason you check RowType)
so you can probably decide what controls/columns to hide/show/bind inside this row databound event
In the winforms world I pull my objects from the DB into a List(Of Whatever) and use the list as the datasource.
This also lets me add extra "convenience" fields in the object so that I can populate it with stuff from other tables.
I don't know asp.net at all so if you can do something similar, it might help.
A really quick solution is to create a custom web control for the status dropdown. The control will always contain the same data. When it renders you populate the datasource. When it gets added to the gridview, the data will be in the drop down. Hope that helps!
I have a Repeater control on ASPX-page defined like this:
<asp:Repeater ID="answerVariantRepeater" runat="server"
onitemdatabound="answerVariantRepeater_ItemDataBound">
<ItemTemplate>
<asp:RadioButton ID="answerVariantRadioButton" runat="server"
GroupName="answerVariants"
Text='<%# DataBinder.Eval(Container.DataItem, "Text")%>'"/>
</ItemTemplate>
</asp:Repeater>
To allow select only one radio button in time I have used a trick form this article.
But now when form is submitted I want to determine which radio button is checked.
I could do this:
RadioButton checkedButton = null;
foreach (RepeaterItem item in answerVariantRepeater.Items)
{
RadioButton control=(RadioButton)item.FindControl("answerVariantRadioButton");
if (control.Checked)
{
checkedButton = control;
break;
}
}
but hope it could be done somehow simplier (maybe via LINQ to objects).
You could always use Request.Form to get the submitted radio button:
var value = Request.Form["answerVariants"];
I think the submitted value defaults to the id of the <asp:RadioButton /> that was selected, but you can always add a value attribute - even though it's not officially an <asp:RadioButton /> property - and this will then be the submitted value:
<asp:RadioButton ID="answerVariantRadioButton" runat="server"
GroupName="answerVariants"
Text='<%# DataBinder.Eval(Container.DataItem, "Text")%>'"
value='<%# DataBinder.Eval(Container.DataItem, "SomethingToUseAsTheValue")%>' />
Since You are using javascript already to handle the radio button click event on the client, you could update a hidden field with the selected value at the same time.
Your server code would then just access the selected value from the hidden field.
I'm pretty sure that the only thing you could use LINQ to Objects for here would be to take the conditions from within the foreach loop and move them to a where clause.
RadioButton checked =
(from item in answerVariantRepeater.Items
let radioButton = (RadioButton)item.FindControl("answerVariantRadioButton")
where radioButton.Checked
select radioButton).FirstOrDefault();