DataGrid CheckBox Select Multiple Rows Column

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Introduction

Multiple row selection in a web DataGrid is a usual requirement and the common and most elegant way to implement that is definitely using CheckBox(s). A checkbox column must of course be accompanied with a CheckAll / UnCheckAll functionality.

Outline

After searching this site, I was surprised not to find anything that suited this requirement completely. I did however find what I was looking for in different segments (acknowledged below). I decided to compile all what I needed in a reusable class / library (for reference). Following is the functionality provided:

• Checkbox column for DataGrid.
• CheckAll, UnCheckAll checkbox in the header without PostBack to the server.
• Static method to register client side JavaScripts.

How to use

Download the supplied .cs file and add to your project. (If your project is in another language, create a new library project and add the supplied .cs to that project, compile the library, and attach the resulting .dll as a reference to your project).

Register a TagPrefix in your aspx page for the new column as follows:

<%@ Register TagPrefix="GridSelectCheckBox" Namespace="solCommon.Web.UI.DataGrid" 
                                                   Assembly="ProjectAssembly" %>

This is, of course, a snippet from my code, you can register any TagPrefix in your page. Should you change the namespace in the supplied .cs file, replace the Namespace attribute accordingly. The Assembly attribute must be your project/library assembly.

The next logical step is to include the column in your DataGrid. You may include the column at any location. Following adds the column at location 0, i.e. the first column:

<asp:datagrid ...>
...
    <Columns>
    <GridSelectCheckBox:DGCheckBoxColumn />
    ...
    </Columns>
...
</asp:datagrid>

Lastly, we use the exposed static method of DGCheckBoxColumn class to register client side JavaScripts for the CheckAll/UncheckAll feature. In the Page_Load method of your aspx page, add the following line:

DGCheckBoxColumn.RegisterClientCheckEvents(this,"Form1");

You should replace "Form1" with the name of the form in which your DataGrid resides.

Your DataGrid is now ready.

You can get the selected indexes or the selected DataKeys by calling one of the exposed properties, i.e. DGCheckBoxColumn.SelectedIndexes and DGCheckBoxColumn.SelectedDataKeys. Let's say, in your button click event handler you try the following:

// since we know that our column in the grid is the first one ...
DGCheckBoxColumn dgchkbxCol = (DGCheckBoxColumn)myGrid.Columns[0];

// iterate through the selection
foreach (int i in dgchkbxCol.SelectedIndexes)
{
   // do something ...
}

Acknowledgements

I must thank the following two articles as I have used much of their contents:

• "Adding a CheckBox Column to a DataGrid" by Dan_P.
• "Using CheckBoxes within the DataGrid control to select records" by Ansil.

Usage and Copyrights

You may freely use/modify the supplied file for your own usage, as long as you retain the acknowledgements presented above. Please don't forget to rate this article. Thanks and good luck.