How to use SelectedIndexChanged or CommandParameter with CommunityToolkit.Mvvm

Question

How to use SelectedIndexChanged or CommandParameter with CommunityToolkit.Mvvm

Bhuwan 821

I am using CommunityToolkit.Mvvm with ObservableObject and ObservableProperty. In the MVVM pattern, how can I trigger the SelectedIndexChanged event for a Picker when an item is selected, or handle changes in an Entry when typing into the textbox?

[RelayCommand]

private void OnChanged()

{

}

<Picker TitleColor="{StaticResource LabelPlaceHolder}"

ItemsSource="{Binding Countrys}"

ItemDisplayBinding="{Binding Name}"

SelectedItem="{Binding SelectedItemCountry,Mode=TwoWay}"
SelectedIndexChanged="{Binding OnChanged}"

FontFamily="OpenSansSemibold"

FontSize="12">

Bhuwan 821

I am trying this way but not working in .NET MAUI 9.0 with latest packages

<Picker
   x:Name="pickerPatrolType"
   Title="{Binding PicPatrolTypeTitle}"
   ItemsSource="{Binding PicPatrolTypes, Mode=TwoWay}"
   ItemDisplayBinding="{Binding GUIValue}"
   SelectedItem="{Binding PicPatrolTypeSelectedItem}"
   SelectedIndex="{Binding PicPatrolTypeIndex, Mode=TwoWay}"
    >
    <Picker.Behaviors>
        <toolkit:EventToCommandBehavior
            EventName="SelectedIndexChanged"
            Command="{Binding CheckPatrolTypeSelectedCommand}" />
    </Picker.Behaviors>
</Picker>

[RelayCommand]
void CheckPatrolTypeSelected()
{
    if (PicPatrolTypeIndex != -1)
    {
        // do stuff
    }
    else
    {
        // do other stuff
    }
}

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Bhuwan 821 Reputation points

2025-01-18T17:00:53.9233333+00:00

I am trying this way but not working in .NET MAUI 9.0 with latest packages

<Picker x:Name="pickerPatrolType" Title="{Binding PicPatrolTypeTitle}" ItemsSource="{Binding PicPatrolTypes, Mode=TwoWay}" ItemDisplayBinding="{Binding GUIValue}" SelectedItem="{Binding PicPatrolTypeSelectedItem}" SelectedIndex="{Binding PicPatrolTypeIndex, Mode=TwoWay}" > <Picker.Behaviors> <toolkit:EventToCommandBehavior EventName="SelectedIndexChanged" Command="{Binding CheckPatrolTypeSelectedCommand}" /> </Picker.Behaviors> </Picker> [RelayCommand] void CheckPatrolTypeSelected() { if (PicPatrolTypeIndex != -1) { // do stuff } else { // do other stuff } }

Answer 1

Bhuwan 821

working after read this and integrate

https://egvijayanand.in/2024/12/19/dotnet-maui-community-toolkit-v10-how-to-fix-bindingcontext-issues-with-behaviors/

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How to use SelectedIndexChanged or CommandParameter with CommunityToolkit.Mvvm

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