CODEWITHSUNDEEP
mauicontroltemplatedatatemplateselector
axa
axa

Reputation: 520

Using a DataTemplateSelector with a ContentTemplate (no xaml)

On a Page, I can use a ControlTemplate to populate the Page's Content.

In this example there are 2 choices for content based on an arbitrary variable, bleDevice, being null or not...

internal void SetContentViewBindingContext(BleDevice bleDevice)
{
    BindingContext = bleDevice;

    var controlTemplate = new ControlTemplate(() =>
    {
        if (bleDevice is null)
            return new NoDeviceDataTemplate().LoadTemplate.Invoke();
        else
            return new BleDeviceDiagnosticItemDataTemplate().LoadTemplate.Invoke();
    });

    _contentView = new() { ControlTemplate = controlTemplate };
    Content = (View)_contentView.ControlTemplate.LoadTemplate();
}

This works fine... And perhaps my understanding of a DataTemplateSelector is wrong, but I would like to use a DataTemplateSelector as it seems to me a more elegant way to select the page's content dynamically. But I can't figure out how to do so.

Fwiw, here is what I've tried that doesn't work, for probably obvious reasons I'm not aware:

ControlTemplate ct = new(new DeviceDetailsDataTemplateSelector().LoadTemplate);
_contentView = new() { ControlTemplate = ct };
Content = (View)_contentView.ControlTemplate.LoadTemplate();

Any advice?

Upvotes: 0

Views: 260

Answers (1)

Liqun Shen-MSFT
Liqun Shen-MSFT

Reputation: 7990

A common usage scenario for a DataTemplate is displaying data from a collection of objects in a ListView, CollectionView or CarouselView. And the DataTemplate is set to the ListView.ItemTemplate property.

A DataTemplateSelector can be used to choose a DataTemplate at runtime based on the value of a data-bound property. This enables multiple data templates to be applied to the same type of object, to choose their appearance at runtime.

The most common scenarios to use DataTemplateSelector is for ListView, CollectionView or CarouselView. A DataTemplateSelector is used to choose a DataTemplate at runtime based on the value of a data-bound property. If you see the official sample, you may find the OnSelectTemplate method in DataTemplateSelector return a DataTemplate instead of a ControlTemplate. So it may not applicable for this case.

Hope it helps!

Upvotes: 0

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