Remote Search in .NET MAUI AutoComplete
The Remote Search functionality of the AutoComplete control allows you to take the user input, trigger custom searching algorithm and assign the results to the ItemSource of the control.
-
LoadingTemplate(DataTemplate)—Defines the template of the loading view.
Implement your custom searching algorithm inside the body of the TextChanged event handler.
Example
Here is an example how the RadAutoComplete Remote Search works:
1. Create the needed business objects, for example type Client with the following properties:
public class Client
{
public Client() { }
public Client(string name, string imageSource)
{
this.Name = name;
this.ImageSource = imageSource;
}
public Client(string name, string email, string imageSource)
{
this.Name = name;
this.Email = email;
this.ImageSource = imageSource;
}
public string Name { get; set; }
public string Email { get; set; }
public string ImageSource { get; set; }
}
2. Create a ViewModel with a collection of Client objects:
public class ClientsViewModel
{
public ClientsViewModel()
{
this.Source = new ObservableCollection<Client>()
{
new Client("Freda Curtis", "[email protected]", "available.png"),
new Client("Jeffery Francis", "[email protected]", "away.png"),
new Client("Eva Lawson", "[email protected]", "available.png"),
new Client("Emmett Santos", "[email protected]", "busy.png"),
new Client("Theresa Bryan", "[email protected]", "available.png"),
new Client("Jenny Fuller", "[email protected]", "busy.png"),
new Client("Terrell Norris", "[email protected]", "away.png"),
new Client("Eric Wheeler", "[email protected]", "away.png"),
new Client("Nida Carty", "[email protected]", "away.png"),
new Client("Niki Samaniego", "[email protected]", "busy.png")
};
}
public ObservableCollection<Client> Source { get; set; }
}
3. Use the following snippet to declare a RadAutoComplete in XAML:
<telerik:RadAutoComplete x:Name="autoCompleteView"
TextChanged="OnTextChanged"
TextSearchPath="Name"
Placeholder="Remote Search..."
SuggestionViewMaxHeight="200">
<telerik:RadAutoComplete.LoadingTemplate>
<DataTemplate>
<HorizontalStackLayout HorizontalOptions="Center"
Margin="0, 20, 0, 20">
<Label Text="Searching... "
FontSize="16"
TextColor="#8E8E93"/>
<telerik:RadBusyIndicator x:Name="busyIndicator"
HeightRequest="24"
WidthRequest="24"
IsBusy="True"
VerticalOptions="Start"
AnimationContentColor="#8660C5"
AnimationType="Animation9"/>
</HorizontalStackLayout>
</DataTemplate>
</telerik:RadAutoComplete.LoadingTemplate>
<telerik:RadAutoComplete.NoResultsTemplate>
<DataTemplate>
<Label Text="No match was found for the specific search. Please try again."
HorizontalOptions="Center"
VerticalOptions="Center"/>
</DataTemplate>
</telerik:RadAutoComplete.NoResultsTemplate>
</telerik:RadAutoComplete>
4. Create a custom searching algorithm and assign the result to the control's ItemsSource inside the TextChanged event handler:
private void OnTextChanged(object sender, Microsoft.Maui.Controls.TextChangedEventArgs e)
{
var autoComplete = (RadAutoComplete)sender;
autoComplete.ItemsSource = null;
this.currentText = e.NewTextValue ?? "";
if (this.currentText.Length >= autoComplete.SearchThreshold && !this.isRemoteSearchRunning)
{
this.isRemoteSearchRunning = true;
Dispatcher.StartTimer(TimeSpan.FromMilliseconds(1500), () =>
{
this.isRemoteSearchRunning = false;
string searchText = this.currentText.ToLower();
autoComplete.ItemsSource = this.viewModel.Source.Where(i => i.Name.ToLower().Contains(searchText));
return false;
});
}
}
This is the result when LoadingTemplate is searching for results:
This is the search complete results:
For the AutoComplete Remote Search example refer to the SDKBrowser Demo application.