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dynamically add columns to existing radgrid

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Grid

This is a migrated thread and some comments may be shown as answers.

tpowell asked on 15 Sep 2008, 10:59 PM

I am having issues when I already have a grid built in the aspx code and am adding columns dynamically from the server side end. The grid will show up with the proper header titles for each column, but as soon as I sort the headers disappear and when I go to the next page each cell is filled with 'System.Data.DataRowView'.

Is their anyway I can make the columns persist in the viewstate? Thanks in advanced.

aspx code:

    
            <telerik:RadGrid ID="Grid1" runat="server" AllowFilteringByColumn="True" 
        
                    AllowPaging="True" OnNeedDataSource="Grid1_NeedDataSource" AllowSorting="True" 
        
                    GridLines="None" ShowGroupPanel="True" AutoGenerateColumns="true" PageSize="50" 
        
                    Skin="Telerik" Visible="false" Width="98%"> 
        
                    <MasterTableView AutoGenerateColumns="False" > 
        
                       <Columns> 
        
                        </Columns> 
        
                    </MasterTableView> 
        
                    <ClientSettings AllowColumnsReorder="True" AllowDragToGroup="True" ReorderColumnsOnClient="True"> 
        
                    </ClientSettings> 
        
                </telerik:RadGrid>

c# code:

    
                        NewColumn = new GridBoundColumn();

                        NewColumn.DataField = "COLUMN1";

                        NewColumn.UniqueName = "COLUMN1";

                        NewColumn.Visible = false;

                        Grid1.MasterTableView.Columns.Add(NewColumn);

11 Answers, 1 is accepted

Accepted

answered on 16 Sep 2008, 05:27 AM

Hi,

Since you trying to add columns to a statically created Grid it is important to add column to the column collection first, before the values for their properties are set.

CS:

    
            private void Page_Load(object sender, System.EventArgs e) 
        
            { 
        
             if ( !IsPostBack ) 
        
             { 
        
               GridBoundColumn boundColumn; 
        
               //Important: first Add column to the collection 
        
               boundColumn = new GridBoundColumn(); 
        
               this.RadGrid1.MasterTableView.Columns.Add(boundColumn); 
        
               //Then set properties 
        
               boundColumn.DataField = "CustomerID"; 
        
               boundColumn.HeaderText = "CustomerID"; 
        
             } 
        
            }

Refer the following help article for more details.
Programmatic creation

Thanks
Shinu.

answered on 18 Feb 2009, 06:34 PM

Hello,

and what if I want to programmatic add a new column to an existing Detail Table?

something like that.

    
            <MasterTableView> 
        
               <detailtables> 
        
                    <Gridtableview> 
        
                        <columns> 
        
                          <gridboundcolumn></gridboundcolumn> 
        
                          <gridboundcolumn></gridboundcolumn> 
        
                          <gridboundcolumn></gridboundcolumn> 
        
                            How to insert more columns here, using the code behind? 
        
                        <columns> 
        
                    <gridtableview> 
        
               </detailtables> 
        
            <columns>......</columns> 
        
            <MastertableView>

I used this successfully to add to the master table, but I cant add to the detail table.

    
                            GridBoundColumn boundColumn; 
        
                            boundColumn = new GridBoundColumn(); 
        
                            RadGrid1.MasterTableView.Columns.Add(boundColumn); 
        
                            boundColumn.DataField = "valor"; 
        
                            boundColumn.HeaderText = "Valor"; 
        
                            boundColumn.UniqueName = "valor"; 
        
                            boundColumn.DataFormatString = "{0:R$###,###.##}";

How can I do the same with DETAILTABLES ?????

Thanxs

answered on 13 Oct 2010, 07:47 AM

Thanx for reply! Well, in fact it does support mixed mode. I have a grid defined in aspx on Master page, with a few common columns (edit and delete). And on content pages I add the rest of the columns from code-behind. It works fine as long as I add columns to the collection before setting their properties.
As for detail table - I create them completely programmatically, so there're no issues too. I ran into problem when I needed to use "self-refferencing hierarchy" - the detail tables, which are created automatically, copy the structure of MasterTableView, but it seems to happen quite early in the life-cycle, thus, my custom columns (which I add from code-behind) are present in detail table only untill the first call-back occures.
We've found a solution though - I created a class which inherits RadGrid, and override OnInit,where I add custom columns to MasterTableView and set SelfHierarchySettings (KeyName and ParentKeyName). This allows custom columns and selfHierarchySettings to be added to the viewstate and they persist thru all call-backs.

answered on 23 Nov 2015, 03:34 PM

[quote]Shinu said:Hi,

Since you trying to add columns to a statically created Grid it is important to add column to the column collection first, before the values for their properties are set.

CS:

    
            private void Page_Load(object sender, System.EventArgs e) 
        
            { 
        
             if ( !IsPostBack ) 
        
             { 
        
               GridBoundColumn boundColumn; 
        
               //Important: first Add column to the collection 
        
               boundColumn = new GridBoundColumn(); 
        
               this.RadGrid1.MasterTableView.Columns.Add(boundColumn); 
        
               //Then set properties 
        
               boundColumn.DataField = "CustomerID"; 
        
               boundColumn.HeaderText = "CustomerID"; 
        
             } 
        
            }

Refer the following help article for more details.
Programmatic creation

Thanks
Shinu. [/quote]

Is this still valid? you say the column must be added before it's properties are set but the article in the link says it must be done afterwards:

[quote]When generating a grid in the Page_Init event handler, grid columns should be added to the Columns collection of the MasterTableView after their attributes are set. No ViewState is required for grid structure to be persisted as it is recreated on each page initialization:[/quote]

answered on 25 Dec 2015, 12:29 PM

Hi Al,

There are 2 ways. First, if you check the different sections of the mentioned help article, you will see that the grid may be created declaratively in the aspx page and the columns added programmatically during Page_Load.

The second approach, which we recommend that you use, is creating the grid during Page_Init, which will enable you using Template columns and other dynamic changes. In this scenario, you first apply the settings and properties of the columns and finally add them to the MasterTableView.Columns collection:
http://docs.telerik.com/devtools/aspnet-ajax/controls/grid/defining-structure/creating-a-radgrid-programmatically#creating-a-radgrid-on-page_init

I hope the clarification was helpful.

Regards,
Eyup
Telerik

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