In Version 19.X, I could place a slider in a grid template column.
<GridColumn Field=@nameof(TaskCompetency.TargetLevel) AllowEditing="true" HeaderText="Target Level" Width="50%">
<Template>
@{ var tmp = (context as TaskCompetency);
<div style="vertical-align:middle; padding-top:15px;">
<SfSlider Min="0" Max="10" Step="1" Value="2" Enabled="true" ReadOnly="false" Type=SliderType.Range >
<SliderTicks Placement="Placement.Before" ShowSmallTicks="false" LargeStep="1">
</SliderTicks>
</SfSlider>
</div>
}
<SfSlider @ref="slider" Value="30"></SfSlider>
</Template>
</GridColumn>
In 20.X, the value does not show up in the slider. I even added a hard-code value slider and same issue.