---
title: Data Binding
order: 100000
seealso: []
---

# Data Binding

The inherited `DataControlBase.ItemsSource` property allows you to bind the Data Grid to a data source (for instance, a collection of business objects). Once bound, the control retrieves items from the data source and presents them as [rows](../rows.md). 

Data Grid displays data source fields (a business object's properties) as [columns](../columns.md). If no column is created, rows display no data.
Columns linked to existing data source fields are called bound columns. Their `GridColumn.FieldName` properties are set to the field names that exist in the data source.

You can also create [unbound columns](unbound-columns.md) (also called calculated columns) to display (or edit and display) values that are not present in the data source.

## Generate Columns Automatically

Enable the `DataGridControl.AutoGenerateColumns` option to automatically generate columns for all data source properties/fields when the Data Grid is initialized at runtime. If the `AutoGenerateColumns` option is disabled, the `PopulateColumns` method allows you to invoke automatic column generation from code.

When a column is auto-generated, the Data Grid control fires two events that you can handle to cancel column generation and customize column settings:

- `DataGridControl.AutoGeneratingColumn` — Fires when a column is about to be added to the `DataGridControl.Columns` collection. Use this event to prevent a column from being added to the grid, or to customize the column's settings.
- `DataGridControl.AutoGeneratedColumns` — Fires after auto-generation of all columns is complete.

## Example - Bind the DataGrid and Generate Columns Automatically

The following code binds a Data Grid to a collection of _EmployeeInfo_ objects, and enables the `AutoGenerateColumns` property to automatically generate columns for all public properties exposed by the _EmployeeInfo_ class. 

![datagrid-binding-autogeneratecolumns-example](/docs/images/datagrid-binding-autogeneratecolumns-example.png)

``` xml
xmlns:mxdg="https://schemas.eremexcontrols.net/avalonia/datagrid"
...
<mxdg:DataGridControl x:Name="dataGrid" ItemsSource="{Binding Employees}" 
 AutoGenerateColumns="True" BorderThickness="1,1">
</mxdg:DataGridControl>
```
``` cs
public partial class MainViewModel : ViewModelBase
{
    [ObservableProperty]
    IList<EmployeeInfo> employees;

    public MainViewModel()
    {
        //Generate sample data.
        Employees = EmployeesData.GenerateEmployeeInfo();
    }
}

public class EmployeeInfo
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public DateTime BirthDate { get; set; }
    public DateTime HiredAt { get; set; }
    public int Experience { get; set; }
    public string Position { get; set; }
    public EmploymentType EmploymentType { get; set; }
    public bool Married { get; set; }
    public string City { get; set; }
    public string Phone { get; set; }
}
```


## Display a Specific Set of Columns in Data Grid

If you need to display a specific set of fields/properties in Data Grid, you can do one of the following:

- Automatically generate columns, and then manually access and delete unnecessary columns from the `DataGridControl.Columns` collection. You can also hide unnecessary columns using the `GridColumn.IsVisible` option.

- Hide specific properties at the data source level, and then use automatic column generation. To prevent generating columns for specific properties of a business object, apply the `Browsable` or `Display(AutoGenerateField)` attribute to the source properties. See the following topic for more information: [Columns](../columns.md).

- Create grid columns manually. 

## Create Columns Manually

You can manually create columns (bound or unbound) in the `DataGridControl.Columns` collection. Columns in the Data Grid control are encapsulated by the  `GridColumn` class. When you create a column, initialize the `GridColumn.FieldName` property to bind a column to a public property/field in the bound data source.

Set the `DataGridControl.AutoGenerateColumns` option to `false` to display only the created columns, and prevent automatic generation of other columns.

See the [Columns](../columns.md) and [Unbound Columns](unbound-columns.md) topics for more information.

## Example - Bind the DataGrid and Generate Columns Manually

The code below creates three columns in the `DataGridControl.Columns` collection. For the "HIRE DATE" column, a `DateEditor` in-place editor is used to display the column's values.

![datagrid-binding-createcolumnsmanually-example](/docs/images/datagrid-binding-createcolumnsmanually-example.png)

``` xml
xmlns:mxdg="https://schemas.eremexcontrols.net/avalonia/datagrid"
xmlns:mxe="https://schemas.eremexcontrols.net/avalonia/editors"
...
<mxdg:DataGridControl x:Name="dataGrid" ItemsSource="{Binding Employees}" 
 AutoGenerateColumns="False" BorderThickness="1,1">
    <mxdg:GridColumn FieldName="FirstName" Width="*" MinWidth="80"/>
    <mxdg:GridColumn FieldName="LastName" Width="*" MinWidth="80"/>
    <mxdg:GridColumn FieldName="HiredAt" Header="Hire Date" Width="*" MinWidth="80">
        <mxdg:GridColumn.EditorProperties>
            <mxe:DateEditorProperties/>
        </mxdg:GridColumn.EditorProperties>
    </mxdg:GridColumn>
</mxdg:DataGridControl>
```
``` cs
public partial class MainViewModel : ViewModelBase
{
    [ObservableProperty]
    IList<EmployeeInfo> employees;

    public MainViewModel()
    {
        Employees = EmployeesData.GenerateEmployeeInfo();
    }
}
public class EmployeeInfo
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public DateTime BirthDate { get; set; }
    public DateTime HiredAt { get; set; }
    public int Experience { get; set; }
    public string Position { get; set; }
    public EmploymentType EmploymentType { get; set; }
    public bool Married { get; set; }
    public string City { get; set; }
    public string Phone { get; set; }
}
```

## Related API

### Properties

- `DataGridControl.Columns` — A collection of grid columns.
- `DataGridControl.AutoGenerateColumns` — Specifies whether Data Grid automatically generates columns for public properties/fields exposed by the data source at runtime. 
- `GridColumn.FieldName` — Specifies the name of the field/property to which a column is bound. 

### Methods

- `PopulateColumns` — Generates columns for public fields/properties exposed by the bound data source.

### Events

- `DataGridControl.AutoGeneratingColumn` — Fires when a column is about to be added to the `DataGridControl.Columns` collection. Use this event to prevent a column from being added to the grid, or to customize the column's settings.
- `DataGridControl.AutoGeneratedColumns` — Fires after automatic generation of all columns is complete.

# See Also
- [Columns](../columns.md)
- [Unbound Columns](unbound-columns.md)
- [Data Editing](../data-editing/index.md)