And luckily for us, Xamarin has exposed an entry point for developers to create their own native renderers and therefore, create custom controls written completely in C#. Underneath Xamarin.Forms every control has a native renderer on each platform that determines how the control is created. You can write your own custom renderer for your cell.
There is a way to work around the performance limitation that comes with custom cell templates containing complex layouts. The Solution – Create a Custom Renderer for your Cell Template But if your cell template contains multiple controls in a layout (such as a Grid or StackLayout), there is no reliable way for FlexGrid to optimize it using the Xamarin.Forms renderer so each cell has to be passed as a View. For instance, if your cell template contains just a single control (such as a Label, an Image, or a Xuni gauge), the grid can reliably pass this to the native platform, and you get great performance. FlexGrid tries to help as best as it can. A ListView with 1,000 text cells will perform better than a ScrollView containing 1,000 labels because it’s been optimized. Item-bound controls like the ListView and FlexGrid perform best when they have an optimized way to render the items.
If your grid has a lot of rows the number of Views can quickly pile up and begin to visibly affect performance. It’s no different than if it were outside of FlexGrid and sitting on your Forms page. Your custom cell template does not have a corresponding component at the native level, so the best way we can “pass” the template to the native level is as a View. The FlexGrid control is not really created in Xamarin.Forms – you just access it from the Forms project. When FlexGrid is rendered on each platform, we actually leverage a native version of FlexGrid to get the best performance. The Problem – Layout Controls within a Cell Template hurt Performance The following markup shows a FlexGrid with three bound columns and one column with a custom cell template. The cell template is essentially a reused component, rendered on every row of the grid for that particular column, and you can customize the cell template for any number of columns. I replace ItemSelected by ItemTapped.With the Xuni FlexGrid control you can create custom cells by defining some UI elements as a cell template. I was using ItemSelected, but the selected item wasn't getting deselected unless until I select any other item in the ListView. Return selectedElement.Equals(currentElemnt) Protected virtual bool Equals(T selectedElement, T currentElemnt) Return Equals(selectedElement, currentElemnt) Var currentElemnt = viewCell.BindingContext as T Public object Convert(object value, Type targetType, object parameter, CultureInfo culture) Return selectedElement.Id.Equals(currentElemnt.Id) ĮlementSelectConverter public abstract class ElementSelectionConverter : IValueConverter where T: class Protected override bool Equals(ColorResponseModel selectedElement, ColorResponseModel currentElemnt) I need only one record to be selected and change the background color in itĬolorConverter public class ColorElementSelectionConverter : ElementSelectionConverter
I create converter but it marks out more records than one. I wan't change the background color in the selected record.
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