I have a simple RadMultiColumnComboBox in my aspx page with tag
<telerik:RadMultiColumnComboBox ID="RadMultiColumnComboBox1" RenderMode="Lightweight" runat="server" Filter="StartsWith" OnItemDataBound="RadMultiColumnComboBox1_ItemDataBound">
</telerik:RadMultiColumnComboBox>
How can I add ColumnsCollection-->MultiColumnComboBoxColumn fields from code behind.
What I am trying to achieve is creating a user control for MultiColumnComboBox so that it can be reused in various screens as per my need. Thus each page has different data and I need to bind the data from code behind instead of doing it from the design page like:
<telerik:RadMultiColumnComboBox runat="server" ID="RadMultiColumnComboBox1"
Width="220px" Height="400"
DataTextField="text" DataValueField="value">
<ColumnsCollection>
<telerik:MultiColumnComboBoxColumn Field="text" Title="Text">
</telerik:MultiColumnComboBoxColumn>
<telerik:MultiColumnComboBoxColumn Field="value" Title="Value">
</telerik:MultiColumnComboBoxColumn>
</ColumnsCollection>
</telerik:RadMultiColumnComboBox>
Please help.
Got the solution.
RadMultiColumnComboBox1.DataValueField = "ID";
RadMultiColumnComboBox1.DataTextField = "Name";
foreach (DataColumn item in dt.Columns)
{
RadMultiColumnComboBox1.ColumnsCollection.Add(new MultiColumnComboBoxColumn()
{
Field = item.ColumnName,
Title = item.ColumnName
});
}
RadMultiColumnComboBox1.DataSource = dt;
RadMultiColumnComboBox1.DataBind();
You have to fetch the data from DB into the data table
I have set a dynamic gridview, which i want to use it in another form so i created it as
public GridView gv = new GridView()
i have set in Page_Load properties of gv to
gv.AutoGenerateColumns = true;
gv.Visible = true;
then i have another grid MyGridView which is static and have data in it. So when i try to copy all static gridview data to dynamic gridview data that is
gv.DataSource = MyGridView.DataSource;
gv.DataBind();
I am not able to view the Grid gv, why is it so? someone told me to add
'Controls.Add(gv) in Page_Load
when i added its showing compile time error, that gv should be in a form with runat=server.
How can i put a dynamic gridview into a form with runat=server?
So my requirement is gv should be visible, how can i achieve this?
Thanks in advance.
you need to use some sort of holders for this try pannel
on aspx page create
<asp:Panel id="panel1" runat="server"></asp:Panel>
on your backednd
do
panel1.Controls.Add(gv)
Place a div with runat="server" into your page
then:
YourDivID.Controls.Add(gv)
I am using a Gridview with datasource is a List. How can I show the header if the List is null or for a empty gridview?
if you are using fx4.0 then Set ShowHeaderWhenEmpty to true in Grid view
please look at below code
asp:GridView ID="gvPreview" runat="server" ShowHeaderWhenEmpty="True"
See A more elegant solution to display GridView header and footer when the data source is empty.
You can use HeaderTemplate property to setup the head programatically or use ListView instead if you are using .NET 3.5.
or
You can even try below
//if data exists
if (dtSource.Rows.Count != 0)
{
grdView.DataSource = dtSource;
grdView.DataBind();
}
else
{
//Other wise add a emtpy "New Row" to the datatable and then hide it after binding.
dtFunding.Rows.Add(dtSource.NewRow());
grdView.DataSource = dtSource;
grdView.DataBind();
grdView.Rows[0].Visible = false;
}
I have a dropdownlist, which dynamically populate data from SQL Server and i wanna manually insert two items on top of the DDL after data binding. So, the DDL would has data something like this:
Select Branch (manually insert)
ALL (manually insert)
AIR
AMP
ABG
...
I tried to achieve it by using code below:
ddlBranch.Items.Insert(0, "Select Branch")
ddlBranch.Items(0).Value = CMM.sExcVal1
ddlBranch.Items.Insert(1, "ALL")
ddlBranch.Items(1).Value = "ALL"
but it comes out giving me the data like this:
Select Branch (manually insert)
ALL (manually insert)
('AIR' branch should be here but it's gone)
AMP
ABG
...
After manually insert the 'ALL' item into the DDL, the 'AIR' is gone which is already replaced by the 'ALL'. How can i remain all the data from server and at the same time i can manually insert two items?
It is much simpler than you think. All you need to do is change the html code as below:
<asp:DropDownList ID="dropdownlist1" runat="server" AppendDataBoundItems="true">
<asp:ListItem>Select Branch</asp:ListItem>
<asp:ListItem>ALL</asp:ListItem>
</asp:DropDownList>
The important thing is the AppendDataBoundItems="true" bit, which will append the remaining items that will be brought back from the SQL Server as normal (however you did it) after the two entries you manually typed in.
Hope that helps.
Ash (UK).
Just skip the automatic databinding.
if (!IsPostBack)
{
list.Items.Clear();
list.Items.Add(new ListItem("Select branch", ""));
list.Items.Add(new ListItem("ALL", "*");
// ----- Just bind your items here from the DB.
foreach (var item in yourCollection)
{
ListItem li = new ListItem(item.Text, item.Value);
list.Items.Add(li);
}
}
Alternatively, if you need this placeholder item in a lot of places in your app - you might want to create a Component that inherits from DropDownList. Then, override the DataBind method -
public override void DataBind()
{
base.DataBind();
ListItem li = new ListItem { Value = String.Empty, Text = "[Select an item ...]" };
this.Items.Insert(0, li);
}
I'm having a problem dynamically adding columns to a GridView. I need to change the layout -- i.e. the included columns -- based on the value in a DropDownList. When the user changes the selection in this list, I need to remove all but the first column and dynamically add additional columns based on the selection.
I have only one column defined in my markup -- column 0, a template column, in which I declare a Select link and another application specific LinkButton. That column needs to always be there. When the ListBoxSelection is made, I remove all but the first column and then re-add the desired columns (in this sample, I've simplified it to always add a "Title" column). Here is a portion of the code:
RemoveVariableColumnsFromGrid();
BoundField b = new BoundField();
b.DataField = "Title";
this.gvPrimaryListView.Columns.Add(b);
this.gvPrimaryListView.DataBind();
private void RemoveVariableColumnsFromGrid() {
int ColCount = this.gvPrimaryListView.Columns.Count;
//Leave column 0 -- our select and view template column
while (ColCount > 1) {
this.gvPrimaryListView.Columns.RemoveAt(ColCount - 1);
--ColCount;
}
}
The first time this code runs through, I see both the static column and the dynamically added "Title" column. However, the next time a selection is made, the first column is generated empty (nothing in it). I see the title column, and I see the first column to its left -- but there's nothing generated within it. In the debugger, I can see that gvPrimaryListView does indeed still have two columns and the first one (index 0) is indeed a template column. In fact, the column even retains it's width which is set as 165px in the markup below (for debugging purposes).
Any ideas?
<asp:GridView ID="gvPrimaryListView" runat="server" Width="100%" AutoGenerateColumns="false"
DataKeyNames="Document_ID" EnableViewState="true" DataSourceID="odsPrimaryDataSource"
AllowPaging="true" AllowSorting="true" PageSize="10" OnPageIndexChanging="activeListView_PageIndexChanging"
AutoGenerateSelectButton="False" OnSelectedIndexChanged="activeListView_SelectedIndexChanged"
Visible="true" OnRowDataBound="CtlDocList_RowDataBound" Font-Size="8pt" Font-Names="Helvetica">
<Columns>
<asp:TemplateField ShowHeader="false">
<ItemTemplate>
<asp:LinkButton EnableTheming="false" ID="CtlSelectDocRowBtn" runat="server" Text="Select"
CommandName="Select" CssClass="gridbutton" OnClick="RowSelectBtn_Click" />
<asp:ImageButton EnableTheming="false" ID="DocViewBtn" runat="server" ImageUrl="../../images/ViewDoc3.png"
CssClass="gridbutton" CommandName="Select" OnClick="DocViewBtn_Click" />
</ItemTemplate>
<ItemStyle Width="165px" />
</asp:TemplateField>
</Columns>
<EmptyDataTemplate>
<asp:Label ID="Label6" runat="server" Text="No rows found." SkinID="LabelHeader"></asp:Label>
</EmptyDataTemplate>
</asp:GridView>
Just some additional information.
It has nothing to do with the fact that it is the first column but everything to do with the fact that it is a TemplateField. If I put a normal column to the left (in the markup) and shift the TemplateField column to the right, the first column renders fine, and the (now second) TemplateField column disappears.
Another strange thing -- the problem doesn't happen the first postback -- OR THE SECOND -- but it starts on the third postback and then continues for subsequent postbacks. I'm stumped.
I recently conquered silmilar issues with dynamic columns in gridviews, perhaps this will help.
First turn the viewstate off
Second add the columns programatically in a function fired in the oninit event
Lastly I used the following helper class to cause the checkboxes to instantiate when the RowDataBound event kicked off. Yes some of it is hard coded.
Heck here is all the code. Have at it :) Warrenty as is, blah blah blah...
Finally since I am just getting my feet wet DotNet any tips would be appreciated [IE don't rip me too much :) ]. And yes 'borrowed' the initial code from the web somewhere, sorry I cant remember off the top of my head :(
-- Fire this off in protected override void OnInit
private void GridViewProject_AddColumns()
{
DataSet dsDataSet = new DataSet();
TemplateField templateField = null;
try
{
StoredProcedure sp = new StoredProcedure("ExpenseReportItemType_GetList", "INTRANETWEBDB", Context.User.Identity.Name);
dsDataSet = sp.GetDataSet();
if (sp.RC != 0 && sp.RC != 3000)
{
labelMessage.Text = sp.ErrorMessage;
}
int iIndex = 0;
int iCount = dsDataSet.Tables[0].Rows.Count;
string strCategoryID = "";
string strCategoryName = "";
iStaticColumnCount = GridViewProject.Columns.Count;
// Insert all columns immediatly to the left of the LAST column
while (iIndex < iCount)
{
strCategoryName = dsDataSet.Tables[0].Rows[iIndex]["CategoryName"].ToString();
strCategoryID = dsDataSet.Tables[0].Rows[iIndex]["CategoryID"].ToString();
templateField = new TemplateField();
templateField.HeaderTemplate = new GridViewTemplateExternal(DataControlRowType.Header, strCategoryName, strCategoryID);
templateField.ItemTemplate = new GridViewTemplateExternal(DataControlRowType.DataRow, strCategoryName, strCategoryID);
templateField.FooterTemplate = new GridViewTemplateExternal(DataControlRowType.Footer, strCategoryName, strCategoryID);
// Have to decriment iStaticColumnCount to insert dynamic columns BEFORE the edit row
GridViewProject.Columns.Insert((iIndex + (iStaticColumnCount-1)), templateField);
iIndex++;
}
iFinalColumnCount = GridViewProject.Columns.Count;
iERPEditColumnIndex = (iFinalColumnCount - 1); // iIndex is zero based, Count is not
}
catch (Exception exception)
{
labelMessage.Text = exception.Message;
}
}
-- Helper Class
public class GridViewTemplateExternal : System.Web.UI.ITemplate
{
#region Fields
public DataControlRowType DataRowType;
private string strCategoryID;
private string strColumnName;
#endregion
#region Constructor
public GridViewTemplateExternal(DataControlRowType type, string ColumnName, string CategoryID)
{
DataRowType = type; // Header, DataRow,
strColumnName = ColumnName; // Header name
strCategoryID = CategoryID;
}
#endregion
#region Methods
public void InstantiateIn(System.Web.UI.Control container)
{
switch (DataRowType)
{
case DataControlRowType.Header:
// build the header for this column
Label labelHeader = new Label();
labelHeader.Text = "<b>" + strColumnName + "</b>";
// All CheckBoxes "Look Up" to the header row for this information
labelHeader.Attributes["ERICategoryID"] = strCategoryID;
labelHeader.Style["writing-mode"] = "tb-rl";
labelHeader.Style["filter"] = "flipv fliph";
container.Controls.Add(labelHeader);
break;
case DataControlRowType.DataRow:
CheckBox checkboxAllowedRow = new CheckBox();
checkboxAllowedRow.Enabled = false;
checkboxAllowedRow.DataBinding += new EventHandler(this.CheckBox_DataBinding);
container.Controls.Add(checkboxAllowedRow);
break;
case DataControlRowType.Footer:
// No data handling for the footer addition row
CheckBox checkboxAllowedFooter = new CheckBox();
container.Controls.Add(checkboxAllowedFooter);
break;
default:
break;
}
}
public void CheckBox_DataBinding(Object sender, EventArgs e)
{
CheckBox checkboxAllowed = (CheckBox)sender;// get the control that raised this event
GridViewRow row = (GridViewRow)checkboxAllowed.NamingContainer;// get the containing row
string RawValue = DataBinder.Eval(row.DataItem, strColumnName).ToString();
if (RawValue.ToUpper() == "TRUE")
{
checkboxAllowed.Checked = true;
}
else
{
checkboxAllowed.Checked = false;
}
}
#endregion
}
best solution for add dynamic column to grid view (ASP) placed on code project by below address :
please check it out :
http://www.codeproject.com/Articles/13461/how-to-create-columns-dynamically-in-a-grid-view
diningphilanderer.myopenid.com has a similar approach to what I would recommend.
The problem is that you have to rebind the grid each time a postback occurs and consequently you have to rebuild the columns. I like to have a method called BindGrid() that first clears the Columns GridView1.Columns.Clear(); then adds them programatically, then sets the datasource and calls databind. Make sure you have viewstate disabled for the grid and you have autogeneratecolumns = false;
I found this earlier today: TemplateField in a GridView doesn't have its ViewState restored when BoundFields are inserted.
Looks like a bug that Microsoft doesn't plan on fixing, so you'll have to try one of the solutions above. I'm having the same problem -- I have some DataBoundFields and some TemplateFields, and after a postback, the TemplateField based columns lose their controls and data.
I have written a short article on the similar topic that deal with dynamically populating GridView column based on the columns selected by the user in the CheckBoxList control. Hope this will help to those looking for simple demonstration How to generate GridView columns dynamically based on user selection?.
void Page_PreRenderComplete(object sender, EventArgs e)
{
// TemplateField reorder bug: if there is a TemplateField based column (or derived therefrom), GridView may blank out
// the column (plus possibly others) during any postback, if the user has moved it from its original markup position.
// This is probably a viewstate bug, as it happens only if a TemplateField based column has been moved. The workaround is
// to force a databind before each response. See https://connect.microsoft.com/VisualStudio/feedback/details/104994/templatefield-in-a-gridview-doesnt-have-its-viewstate-restored-when-boundfields-are-inserted
//
// This problem is also happening for grid views inside a TabPanel, even if the TemplateField based columns have not
// been moved. Also do a databind in that case.
//
// We also force a databind right after the user has submitted the column chooser dialog.
// (This is because the user could have moved TemplateField based column(s) but ColChooserHasMovedTemplateFields()
// returns false -- ie when the user has moved all TemplateField based columns back to their original positions.
if ((!_DataBindingDone && (ColChooserHasMovedTemplateFields() || _InTabPanel)) || _ColChooserPanelSubmitted || _ColChooserPanelCancelled)
DataBind();
// There is a problem with the GridView in case of custom paging (which is true here) that if we are on the last page,
// and we delete all row(s) of that page, GridView is not aware of the deletion during the subsequent data binding,
// will ask the ODS for the last page of data, and will display a blank. By PreRenderComplete, it will somehow have
// realized that its PageIndex, PageCount, etc. are too big and updated them properly, but this is too late
// as the data binding has already occurred with oudated page variables. So, if we were on the last page just before
// the last data binding (_LastPageIndex == _LastPageCount - 1) and PageIndex was decremented after the data binding,
// we know this scenario has happened and we redo the data binding. See http://scottonwriting.net/sowblog/archive/2006/05/30/163173.aspx
// for a discussion of the problem when the GridView uses the ODS to delete data. The discussion also applies when we
// delete data directly through ClassBuilder objects.
if (_LastPageIndex == _LastPageCount - 1 && PageIndex < _LastPageIndex)
DataBind();
if (EnableColChooser)
{
if (!_IsColChooserApplied)
ApplyColChooser(null, false, false);
else
{
// The purpose of calling ApplyColChooser() here is to order the column headers properly. The GridView
// at this point will have reverted the column headers to their original order regardless of ViewState,
// so we need to apply our own ordering. (This is not true of data cells, so we don't have to apply
// ordering to them, as reflected by the parameters of the call.)
// If we have already processed column reordering upon the column chooser panel being submitted,
// don't repeat the operation.
if (!_ColChooserPanelSubmitted)
ApplyColChooser(null, false, true);
}
}
}
I found this little nugget in the documentation, under the DataControlFieldCollection Class.
If you are using the GridView or DetailsView control, the DataControlField objects that are automatically created (for example, when the AutoGenerateColumns property is true) are not stored in the publicly accessible fields collection. You can only access and manipulate DataControlField objects that are not automatically generated.
I guess the answer is to do all of your column manipulation in code, and then your approach should work fine.
Instead of dynamically adding columns, could you define them at the outset and hide/show them as needed (either with Visible="false" or setting the CssClass of the control/header/footer to a class with "display: none;")? I use this method in some of my code, including template columns, with no issues.
Sorry, Decker. I missed a few key points obviously.. :)
If this is still a problem for you, I wonder if it makes a difference what you have in your item template? If you just put some text in there, then refresh the page a few times, does the text appear on the first load, then not on the second?
Also, when the problem arises is there any html markup at all in the cells or are they completely empty?