How to do Select All in MVC GridView with a checkbox column and Update all Checked rows

Hello Rajesh,
In your scenario I suggest using the ClientGridView.SelectAllRowsOnPage method to select all unselected rows displayed on a current GridView page.

As for updating all the selected rows at once in a corresponding controller action, you can use the following approach:

1. Pass key values of all the selected rows as an action parameter using the ClientGridView.PerformCallback method:

JavaScript
function OnUpdateSelectedRows(s, e) {  
    var keys = grid.GetSelectedKeysOnPage();  
    grid.PerformCallback({ selectedIDs: keys.join() });  
}  

2. In a controller action, convert a passed string to a corresponding array of a key value and update all the rows at the data source level. For example:

C#
public ActionResult CustomCallbackAction(string selectedIDs) {  
    string[] arrayIDs = selectedIDs.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);  
    List<Person> persons = PersonsList.GetPersons();  
    for(int i = 0; i < arrayIDs.Length; i++) {  
        Person editedPerson = persons.Where(m => m.PersonID == Convert.ToInt32(arrayIDs[i])).First();  
        if(editedPerson != null) {  
            editedPerson.FirstName = editedPerson.FirstName + " (UPDATED)";  
        }  
    }  
    return PartialView("GridViewPartial", PersonsList.GetPersons());  
}  

I have attached a sample project to demonstrate this approach in action.
I hope you will find this sample helpful.