Commands Overview

The DataGrid provides an intuitive set of APIs that allow different aspects of its behavior to be handled and/or overridden. To control the behavior of the component, you can add commands through the Commands property, which gets a collection with all of the custom commands registered with the CommandService property.

CommmandService

The DataGrid exposes a CommandService property which provides the following methods:

• CanExecuteCommand(CommandId id, object parameter)—Determines whether the command, associated with the specified Id, can be executed based on the provided parameter. If a custom command with the provided Id is added to the Commands collection, it will take precedence over the default (built-in) one.

• CanExecuteDefaultCommand(CommandId id, object parameter)—Determines whether the default command, associated with the specified Id, can be executed based on the provided parameter.

• ExecuteCommand(CommandId id, object parameter)—Attempts to find the command, associated with the specified Id, and to perform its Execute routine by using the provided parameter. If a custom command with the provided Id is added to the Commands collection, it will take precedence over the default one.

• ExecuteDefaultCommand(CommandId id, object parameter)—Executes the default command (without looking for user-defined commands) that is associated with the specified Id.

Command Types

The DataGrid supports the following types of commands:

• DataGridCommand—All the default commands within the DataGrid derive from the base DataGridCommand. Think of this command as a UI-related one as it operates over the DataGrid instance that owns the command.

  Custom commands take precedence over the built-in (default) ones.

• DataGridUserCommand—This specific command type provides an abstraction for the UI-related commands over a stateless and UI-agnostic generic command implementation. DataGridUserCommand exposes the following properties:

  • Id—Gets or sets the CommandId member with which this command is associated.
  • Command—Gets or sets the generic ICommand implementation that may come from the ViewModel.
  • EnableDefaultCommand—Gets or sets a value indicating whether the default UI command associated with the specified Id will be executed. The default value is True.

Bind to a Command in the ViewModel

<Grid xmlns:grid="using:Telerik.UI.Xaml.Controls.Grid" 
      xmlns:gridCommands="using:Telerik.UI.Xaml.Controls.Grid.Commands"> 
    <grid:RadDataGrid Width="600" Height="460" x:Name="grid"> 
        <grid:RadDataGrid.Commands> 
            <gridCommands:DataGridUserCommand Id="CellTap" Command="{Binding MyCommand}"/> 
        </grid:RadDataGrid.Commands> 
    </grid:RadDataGrid> 
</Grid> 

CommandId Enumeration

All the predefined commands are identified by a member of the CommandId enumeration. This is actually the key that relates a command instance to a particular action or routine within the owning grid. To register a custom command, either inherit the DataGridCommand class and override its CanExecute and Execute methods, or instantiate a DataGridUserCommand instance and set its Command property. In both cases you need to set the Id property of the new command so that it can be properly associated with the desired action or event.

CommandId supports the following enumerations:

• BeginEdit
• CancelEdit
• CommitEdit
• ColumnHeaderTap
• GroupHeaderTap
• CellTap
• CellDoubleTap
• CellPointerOver
• GenerateColumn
• DataBindingComplete
• FlyoutGroupHeader
• FilterButtonTap
• ToggleColumnVisibility