.NET MAUI TemplatedPicker Templates
The TemplatedPicker for .NET MAUI provides the following templates:
-
SelectorTemplate
(ControlTemplate
)—Defines the template used for displaying the selector of the picker. -
PlaceholderTemplate
(ControlTemplate
)—Defines the template visualized for the placeholder. -
DisplayTemplate
(ControlTemplate
)—Defines the template visualized when an item from the selector was picked.
When you use the SelectorSettings
property (of type Telerik.Maui.Controls.PickerPopupSelectorSettings
), you can define the following templates:
-
HeaderTemplate
(ControlTemplate
)—Defines what will be displayed inside the dialog (popup) header. -
FooterTemplate
(ControlTemplate
)—Defines what will be displayed inside the dialog (popup) footer.
Example
The following example demonstrates how to define the templates.
1. Define a sample TemplatedPicker:
<telerik:RadTemplatedPicker x:Name="picker"
SelectedValue="{Binding FromCity, Mode=TwoWay}"
DisplayMemberPath="Name"
SelectorTemplate="{StaticResource SelectorTemplate}"
AutomationId="templatedPicker">
<telerik:RadTemplatedPicker.PopupSettings>
<telerik:PickerPopupSettings HeaderTemplate="{StaticResource HeaderTemplate}"/>
</telerik:RadTemplatedPicker.PopupSettings>
</telerik:RadTemplatedPicker>
Define the Selector Template
<ControlTemplate x:Key="SelectorTemplate">
<Grid ColumnDefinitions="*, *"
HeightRequest="250">
<Grid.Style>
<OnPlatform x:TypeArguments="Style">
<On Platform="WinUI">
<Style TargetType="Grid">
<Setter Property="WidthRequest" Value="{Binding Width, Source={x:Reference picker}}" />
</Style>
</On>
</OnPlatform>
</Grid.Style>
<telerik:RadSpinner x:Name="countriesSpinner"
Grid.Column="0"
ItemsSource="{Binding Countries}"
DisplayMemberPath="Name" />
<telerik:RadSpinner x:Name="citiesSpinner"
Grid.Column="1"
ItemsSource="{Binding SelectedItem.Cities, Source={x:Reference countriesSpinner}}"
SelectedItem="{TemplateBinding SelectedValue}"
DisplayMemberPath="Name" />
</Grid>
</ControlTemplate>
Define the Header Template
<ControlTemplate x:Key="HeaderTemplate">
<Grid BackgroundColor="DarkGray">
<Grid.ColumnDefinitions>
<ColumnDefinition />
<ColumnDefinition />
</Grid.ColumnDefinitions>
<Label Text="Origin Country"
HorizontalOptions="Center"
VerticalOptions="Center"
TextColor="White" />
<Label Grid.Column="1"
Text="Origin City"
HorizontalOptions="Center"
VerticalOptions="Center"
TextColor="White" />
</Grid>
</ControlTemplate>
2. Add the following data item for the first spinner:
public class Country : NotifyPropertyChangedBase
{
private string name;
public Country()
{
this.Cities = new ObservableCollection<City>();
}
public string Name
{
get
{
return this.name;
}
set
{
if (value != this.name)
{
this.UpdateValue(ref this.name, value);
}
}
}
public ObservableCollection<City> Cities { get; }
}
3. Add the following data item for the second spinner:
public class City : NotifyPropertyChangedBase
{
private string name;
public string Name
{
get
{
return this.name;
}
set
{
if (value != this.name)
{
this.UpdateValue(ref this.name, value);
}
}
}
}
4. Define a sample ViewModel
:
public class LocationViewModel : NotifyPropertyChangedBase
{
private Country fromCountry;
private City fromCity;
public LocationViewModel()
{
this.Countries = new ObservableCollection<Country>
{
new Country
{
Name = "Austria",
Cities =
{
new City { Name = "Graz" },
new City { Name = "Innsbruck" },
new City { Name = "Linz" },
new City { Name = "Ratz" },
new City { Name = "Salzburg" },
new City { Name = "Vienna" },
new City { Name = "Wolfsberg" },
new City { Name = "Zeltweg" }
}
},
new Country
{
Name = "Belgium",
Cities =
{
new City { Name = "Antwerp" },
new City { Name = "Assesse" },
new City { Name = "Bruges" },
new City { Name = "Charleroi" },
new City { Name = "Lint" },
new City { Name = "Ranst" },
new City { Name = "Schaffen" },
new City { Name = "Veurne" },
new City { Name = "Zingem" },
}
},
new Country
{
Name = "Denmark",
Cities =
{
new City { Name = "Aalborg" },
new City { Name = "Aarhus" },
new City { Name = "Billund" },
new City { Name = "Copenhagen" },
new City { Name = "Karup" },
new City { Name = "Odense" },
new City { Name = "Viborg" },
new City { Name = "Vojens" }
}
},
new Country
{
Name = "France",
Cities =
{
new City { Name = "Aurillac" },
new City { Name = "Belley" },
new City { Name = "Carcassonne" },
new City { Name = "Caen" },
new City { Name = "Deauville" },
new City { Name = "La Rochelle" },
new City { Name = "Nice" },
new City { Name = "Marseille" },
new City { Name = "Paris" },
new City { Name = "Rodez" }
}
},
new Country
{
Name = "Germany",
Cities =
{
new City { Name = "Baden-Baden" },
new City { Name = "Berlin" },
new City { Name = "Borkum" },
new City{ Name = "Bremen" },
new City{ Name = "Dortmund" },
new City{ Name = "Dresden" },
new City{ Name = "Hamburg" },
new City{ Name = "Hannover" },
new City{ Name = "Leipzig" },
new City{ Name = "Mannheim" },
new City{ Name = "Munich" },
new City{ Name = "Nuremberg" }
}
},
new Country
{
Name = "Italy",
Cities =
{
new City { Name = "Aosta" },
new City { Name = "Bari" },
new City { Name = "Bologna" },
new City { Name = "Parma" },
new City { Name = "Rimini" },
new City { Name = "Rome" }
}
},
new Country
{
Name = "Netherlands",
Cities =
{
new City { Name = "Amsterdam" },
new City { Name = "Bonaire" },
new City { Name = "Eindhoven" },
new City { Name = "Maastricht" },
new City { Name = "Rotterdam" }
}
},
new Country
{
Name = "Portugal",
Cities =
{
new City { Name = "Braga" },
new City { Name = "Cascais" },
new City { Name = "Lisbon" },
new City { Name = "Porto" }
}
},
new Country
{
Name = "Spain",
Cities =
{
new City { Name = "Alicante" },
new City { Name = "Barcelona" },
new City { Name = "Madrid" },
new City { Name = "Seville" },
new City { Name = "Valencia" },
new City { Name = "Zaragoza" }
}
},
new Country
{
Name = "United Kingdom",
Cities =
{
new City { Name = "Bristol" },
new City { Name = "Liverpool" },
new City { Name = "London" },
new City { Name = "Manchester" },
new City { Name = "Norwich" },
new City { Name = "Southampton" }
}
},
};
}
public Country FromCountry
{
get
{
return this.fromCountry;
}
set
{
if (value != this.fromCountry)
{
this.UpdateValue(ref this.fromCountry, value);
}
}
}
public City FromCity
{
get
{
return this.fromCity;
}
set
{
if (value != this.fromCity)
{
this.UpdateValue(ref this.fromCity, value);
}
}
}
public ObservableCollection<Country> Countries { get; }
}
5. Set the defined LocationViewModel
as a BindingContext
of the page:
this.BindingContext = new LocationViewModel();
6. In addition to this, you need to add the following namespace:
xmlns:telerik="http://schemas.telerik.com/2022/xaml/maui"
The following image shows the TemplatedPicker visual structure: