Question

I have UserControl(AllCustomerView) in project and its Viewmodel as ALlCustomerViewModel consists a property as SearchText.
SearchText is selected value for TextBox inside a listview in UserControl.
SearchItem is set as customerViewmdel for SearchText.
But in listview , SearchItem is not set as selected

in AllCustomerView.xaml

<TextBlock>
<TextBox 
        Width="150" 
        Text="{Binding Path=SearchText, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}">
</TextBox>
<Button 
         Command="{Binding Path=SearchCommand}"
         Content=" Search ">
</Button>
</TextBlock>

<ListView
            SelectedValue="{Binding Path=SearchText}"
            ItemsSource="{Binding Path=AllCustomers}"
            FontFamily="Tahoma"
            FontSize="14"
            ItemContainerStyle="{StaticResource CustomerItemStyle}" 
            IsSynchronizedWithCurrentItem="True">
            <ListView.View>
                <GridView>
                    <GridViewColumn>
                        <GridViewColumn.CellTemplate>
                            <DataTemplate>
                                <Button 
                                    Command="{Binding ElementName=Root, Path=DataContext.DeleteCommand}"
                                    Content="x"
                                    FontFamily="Tahoma"
                                    FontSize="10"
                                    />
                            </DataTemplate>
                        </GridViewColumn.CellTemplate>
                    </GridViewColumn>
                    <GridViewColumn>
                        <GridViewColumn.CellTemplate>
                            <DataTemplate>
                                <Button 
                                     FontFamily="Tahoma"
                                    FontSize="10"
                                    Content="Edit"
                                    Command="{Binding Path=DataContext.Editcommand,ElementName=Root}"
                                    />
                            </DataTemplate>
                        </GridViewColumn.CellTemplate>
                    </GridViewColumn>
                    <GridViewColumn
                        Header="CustomerID"
                        Width="130"
                        DisplayMemberBinding="{Binding Path=CustomerID}"/>
                    <GridViewColumn
                        Header="Contact Name"
                        Width="130"
                        DisplayMemberBinding="{Binding Path=ContactName}"/>
                    <GridViewColumn
                        Header="Company Name"
                        Width="130"
                        DisplayMemberBinding="{Binding Path=CompanyName}"/>
                    <GridViewColumn
                        Width="130"
                        Header="Contact Name"
                        DisplayMemberBinding="{Binding Path=ContactTitle}"
                        />
                </GridView>
            </ListView.View>
        </ListView>

and its viewmodel(AllcustomerViewModel.cs)

public ICommand SearchCommand
        {
            get
            {
                if (_search == null)
                    _search = new Relaycommand(SearchCustomer);
                return _search;
            }
        }

 public void SearchCustomer(object o)
 {
            System.Windows.Forms.MessageBox.Show(SearchItem.ToString());

}

 public string searchText;
 public string SearchText
 {
     get { return searchText; }
     set 
     {
       searchText = value;
       var customerExsits = AllCustomers.Where(q => q.CustomerID.Trim().Equals(searchText));
        if (customerExsits.Any())
                {
                    SearchItem = customerExsits.Single();
                }

            }
        }

public CustomerViewModel SearchItem
{
            get;
            set;
}

what should i set in SelectedValue in ListView, whether to set Customerviewmodel(as SelectedItem) or to set CustomerID(as SearchText)?

Answer 1

You should do the following:

1. Use this binding in your ListView: SelectedItem="{Binding Path=SearchItem }". Don’t use SelectedValue.

2. Implement INotifyPropertyChanged in your ViewModel and raise the PropertyChanged event in the setter of the SearchItem property. Obviously, you need to change this property from an automatic one to a classical one with a backing field:

   public CustomerViewModel SearchItem
   {
       get { return _searchItem; }
       set
       {
           if(value == _searchItem)
               return;
           _searchItem = value;
           RaisePropertyChanged("SearchItem");
       }
   }