CODEWITHSUNDEEP
c#wpf
Zurreal
Zurreal

Reputation: 301

Prevent update when textbox is empty during data binding

I have a ListView and when the user selects an item in the listview it will be displayed on a `TextBox for updating.

The problem is how can I prevent the SelectedItem from updating when the user clears the text in the TextBox

C# Code:

private void Update_Button(object sender, RoutedEventArgs e)
{

    string fname = tb_firstname.Text;
    string lname = tb_lastname.Text;
    var selectedEmployee = (Employee)lview.SelectedItem;

    if (fname != null && lname != null)
    {
            selectedEmployee.FirstName = fname;
            selectedEmployee.LastName = lname; 
            Refresh();
    }           

}

private void Refresh()
{
    ICollectionView view = CollectionViewSource.GetDefaultView(employees);
    view.Refresh();
}          


private void lv_selectionChanged(object sender, SelectionChangedEventArgs e)
{ 
    var selectedEmployee = (Employee) lview.SelectedItem;
    if(selectedEmployee != null)
    {
        tb_firstname.Text = selectedEmployee.FirstName;
        tb_lastname.Text = selectedEmployee.LastName;
    }

}

XAML

<ListView ItemsSource="{Binding}" IsSynchronizedWithCurrentItem="True" Height="93" Name="lview" SelectionChanged="lv_selectionChanged">
            <ListView.ItemTemplate>
                <DataTemplate>
                    <StackPanel Orientation="Horizontal">
                        <TextBlock Text="{Binding FirstName}"></TextBlock>
                        <TextBlock Text="{Binding LastName}"></TextBlock>                            
                    </StackPanel>
                </DataTemplate>
            </ListView.ItemTemplate>

Upvotes: 0

Views: 117

Answers (2)

K Mehta
K Mehta

Reputation: 10553

You should use the String.IsNullOrEmpty function. You can find more info about it on MSDN.

if (!String.IsNullOrEmpty(fname) && !String.IsNullOrEmpty(lname))
{
   ...
}

Upvotes: 1

gayan1991
gayan1991

Reputation: 795

if (tb_firstname.Text != "")
{not empty code}

or 

if (!string.empty(tb_firstname.Text))
{not empty code}

Upvotes: 1

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