DxGridDataColumn.UnboundType Property

Indicates that the column is unbound and specifies its data type.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v23.2.dll

NuGet Package: DevExpress.Blazor

Declaration

[DefaultValue(GridUnboundColumnType.Bound)]
[Parameter]
public GridUnboundColumnType UnboundType { get; set; }

Property Value

Type	Default	Description
GridUnboundColumnType	Bound	An enumeration value.

Available values:

Name	Description
Bound	The column is bound to a data field. This field specifies the column data type.
Integer	The column contains Int32 values.
Decimal	The column contains Decimal values.
DateTime	The column contains DateTime values.
String	The column contains String values.
Boolean	The column contains Boolean values.
Object	The column contains Object values.

Remarks

To create an unbound column, add a DxGridDataColumn object to the Columns collection and specify the column’s UnboundType and FieldName properties. The FieldName property value should be unique and should not match field names in the Grid’s data source.

You can use the following API to obtain column values:

UnboundExpression

Specifies an expression to evaluate values for the unbound column. An expression might consist of field names, constants, operators, and functions.

UnboundColumnData

Allows you to implement custom logic or obtain column values from a custom/external data source.

<DxGrid Data="forecasts" UnboundColumnData="Grid_CustomUnboundColumnData">
    <Columns>
        <DxGridDataColumn FieldName="Date" Caption="Date" />
        <DxGridDataColumn FieldName="TemperatureC" Caption="@("Temperature (\x2103)")" />
        <DxGridDataColumn FieldName="TemperatureF" Caption="@("Temperature (\x2109)")"
                          UnboundType="GridUnboundColumnType.Decimal"
                          UnboundExpression="32 + [TemperatureC] / 0.5556" />
        <DxGridDataColumn FieldName="Summary"
                          UnboundType="GridUnboundColumnType.String" />
    </Columns>
</DxGrid>

@code {
    private WeatherForecast[]? forecasts;

    protected override async Task OnInitializedAsync() {
        forecasts = await ForecastService.GetForecastAsync(DateTime.Now);
    }

    void Grid_CustomUnboundColumnData(GridUnboundColumnDataEventArgs e) {
        if (e.FieldName == "Summary") {
            int temperature = Convert.ToInt32(e.GetRowValue("TemperatureC"));
            e.Value = GetTemperatureString(temperature);
        }
    }

    static string GetTemperatureString(int value) {
        if (value < -10)
            return "Cool";
        if (value >= -10 && value < 5)
            return "Chilly";
        if (value >= 5 && value < 15)
            return "Warm";
        return "Hot";
    }
}

View Example: Create and Edit Unbound Columns

Limitations

• When you use a Server Mode data source, the Grid does not support unbound columns whose values are populated in the UnboundColumnData event handler. You can create unbound columns whose values are calculated based on the UnboundExpression.
• When you use a GridDevExtremeDataSource, the Grid does not support unbound columns.

Implements

UnboundType