DxGrid.CustomizeElement Event

Allows you to customize grid elements.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v24.1.dll

NuGet Package: DevExpress.Blazor

Declaration

[Parameter]
public Action<GridCustomizeElementEventArgs> CustomizeElement { get; set; }

Parameters

Type	Description
GridCustomizeElementEventArgs	An object that defines data for this event.

Remarks

The CustomizeElement event fires each time the Grid componenent is re-rendered, for instance when you update data from the asynchronous data source or call the AutoFitColumnWidths() method.

The event fires for most grid elements. Use the ElementType, VisibleIndex, and Column event arguments to get information about the currently processed element.

The CssClass, Style, and Attributes event arguments allow you to customize element settings.

Task-Based Examples

Customize Appearance and Display a Custom Tooltip

The following code customizes the appearance of grid elements that meet the following criteria:

• Data rows with Total > 1000 are highlighted.
• All Total values are bold.
• If the grid rows are grouped by Country, the group row’s tooltip displays group summary values.

Run Demo: Conditional Formatting View Example: Conditional Formatting

<DxGrid @ref="Grid" CustomizeElement="Grid_CustomizeElement" ... />
@* ... *@
@code {
    // ...
    IGrid Grid { get; set; }
    void Grid_CustomizeElement(GridCustomizeElementEventArgs e) {
        if(e.ElementType == GridElementType.DataRow && (System.Decimal)e.Grid.GetRowValue(e.VisibleIndex, "Total") > 1000) {
            e.CssClass = "highlighted-item";
        }
        if(e.ElementType == GridElementType.DataCell && e.Column.Name == "Total") {
            e.Style = "font-weight: 800";
        }
        if(e.ElementType == GridElementType.GroupRow && e.Column.Name == "Country") {
            var summaryItems = e.Grid.GetGroupSummaryItems().Select(i => e.Grid.GetGroupSummaryDisplayText(i, e.VisibleIndex));
            e.Attributes["title"] = string.Join(", ", summaryItems);
        }
    }
}

.highlighted-item > td {
    background-color: var(--bs-danger-border-subtle)
}
.highlighted-item > td:first-child {
    background-color: transparent;
}

Show a Custom Context Menu

The following code sample invokes a custom context menu for column headers and rows:

The oncontextmenu:preventDefault attribute disables the standard browser context menu. In the Grid’s CustomizeElement event handler, subscribe to the contextmenu event that displays a custom context menu.

View Example: Show the Context Menu and Customize its Appearance Watch Video: Grid - Add the Context Menu

<DxGrid @ref="Grid" CustomizeElement="Grid_CustomizeElement" @oncontextmenu:preventDefault ... />

@code {
    GridContextMenuContainer ContextMenuContainer { get; set; }
    void Grid_CustomizeElement(GridCustomizeElementEventArgs e) {
        if(GridContextMenuHelper.IsContextMenuElement(e.ElementType)) {
            e.Attributes["oncontextmenu"] = EventCallback.Factory.Create<MouseEventArgs>(
                this,
                async mArgs => await ContextMenuContainer.Grid_ContextMenu(e, mArgs)
            );
        }
    }
    ...
}

Implement Row Drag and Drop Functionality

If your DxGrid uses an ObservableCollection<T> data source, you can incorporate row drag and drop support for the following usage scenarios:

• Drag rows in a single grid (reorder rows)
• Drag rows between two grids
• Drag rows between two grids and drop them at a specified position

Our drag-and-drop implementation uses three jQuery widgets: (draggable, droppable, and sortable).

View Example: Incorporate Drag and Drop Support

Highlight Modified Cells

View Example: Enable Batch Data Editing with Entity Framework Core Run Demo: Batch Edit

<div>
    <DxGrid @ref="Grid"
            Data="Data"
            ValidationEnabled="false"
            KeyFieldName="EmployeeId"
            EditMode="GridEditMode.EditCell"
            EditModelSaving="Grid_EditModelSaving"
            CustomizeElement="Grid_CustomizeElement"
            CustomizeEditModel="Grid_CustomizeEditModel">
        <Columns>
            <DxGridDataColumn FieldName="FirstName" />
            <DxGridDataColumn FieldName="LastName" />
            <DxGridDataColumn FieldName="Title" />
            <DxGridDataColumn FieldName="HireDate" />
            <DxGridCommandColumn Width="30px" NewButtonVisible="false">
            @* ... *@
            </DxGridCommandColumn>
        </Columns>
        @* ... *@
    </DxGrid>
</div>

@code {
    IGrid Grid { get; set; }
    IList<Employee> Data { get; set; }
    @* ... *@
    void Grid_CustomizeElement(GridCustomizeElementEventArgs e) {
        if (e.ElementType == GridElementType.DataCell) {
            var employee = (Employee)Grid.GetDataItem(e.VisibleIndex);
            var column = (IGridDataColumn)e.Column;
            if (TryGetChangedEntityEntry(employee, out var entityEntry)) {
                if (entityEntry.State == EntityState.Added || entityEntry.Property(column.FieldName).IsModified)
                    e.CssClass = "grid-modified-cell";
            }
        }
    }
    @* ... *@
}

Alternate Row Style

Run Demo: Alternating Row Style

void Grid_CustomizeElement(GridCustomizeElementEventArgs e) {
    if(e.ElementType == GridElementType.DataRow && e.VisibleIndex % 2 == 1) {
        e.CssClass = "alt-item";
    }
}

.alt-item {
    background-color: color-mix(in srgb, var(--bs-gray-300), transparent 50%);
}

Change Focus and Selection Color

<DxGrid @ref="Grid" CustomizeElement="Grid_CustomizeElement" ... />

@code {
    IGrid Grid { get; set; }
    void Grid_CustomizeElement(GridCustomizeElementEventArgs e) {
        if (e.ElementType == GridElementType.DataRow && Grid.IsRowSelected(e.VisibleIndex)) {
            e.CssClass = "custom-selection-style";
        }
        if (e.ElementType == GridElementType.DataRow && Grid.IsRowFocused(e.VisibleIndex)) {
            e.CssClass = "custom-focus-style";
        }
    }
...
}

Modify Data Cell Paddings

void Grid_CustomizeElement(GridCustomizeElementEventArgs e) {
    if (e.ElementType == GridElementType.DataCell) {
        e.Style = "padding: 0px";
    }
}

Conditionally Hide Commands

void Grid_CustomizeElement(GridCustomizeElementEventArgs e) {
    if (e.ElementType == GridElementType.CommandCell && 
            (System.Int32)e.Grid.GetRowValue(e.VisibleIndex, "Profit") < 0) {
        e.CssClass = "hidden-item";
    }
}

.hidden-item button {
    visibility: hidden;
}

Modify Column Header Style Based on Sort Settings

void Grid_CustomizeElement(GridCustomizeElementEventArgs e) {
    if (e.ElementType == GridElementType.HeaderCell) {
        var column = (DxGridDataColumn)e.Column;
        if (column.AllowSort == false)
            e.CssClass = "nonsortable-header";
        else
            e.CssClass = "my-header-cell";
    }
}

.nonsortable-header {
    background-color: red !important;
}
.my-header-cell[aria-sort="ascending"] {
    background-color: green !important;
}
.my-header-cell[aria-sort="descending"] {
    background-color: red !important;
}