I am new to WPF.
I am trying to bind collection of string to combobox.
public ObservableCollection<string> ListString {get; set;}
Binding and datacontext are set as follows
<Window
x:Class="Assignment2.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:validators="clr-namespace:Assignment2"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525"
DataContext="{Binding RelativeSource={RelativeSource Self}, Path=.}">
<Grid>
<ComboBox Height="23" HorizontalAlignment="Left" Margin="109,103,0,0" Name="StringComboBox" VerticalAlignment="Top" Width="120" SelectionChanged="StringComboBox_SelectionChanged">
<ComboBox.ItemsSource>
<Binding Path="ListString" BindsDirectlyToSource="True" Mode="TwoWay" UpdateSourceTrigger="PropertyChanged"></Binding>
</ComboBox.ItemsSource>
</ComboBox>
I came to know that this is happening because collection is updating. If I write
public MainWindow()
{
InputString = "";
ListString = new ObservableCollection<string>();
ListString.Add("AAA");
ListString.Add("BBB");
ListString.Add("CCC");
InitializeComponent();
}
It does work but if I am move InitializeComponent()
above at first line as follows, it doesn't work.
public MainWindow()
{
InitializeComponent();
InputString = "";
ListString = new ObservableCollection<string>();
ListString.Add("AAA");
ListString.Add("BBB");
ListString.Add("CCC");
}
What Should I do??
Solved the problem. Implemented INotifyPropertyChanged as follows
public partial class MainWindow : Window, INotifyPropertyChanged
modified the accessors as follows
private ObservableCollection<string> listString;
public ObservableCollection<string> ListString
{
get
{
return listString;
}
set
{
listString = value;
NotifyPropertyChanged("ListString"); // method implemented below
}
}
and added the following event and method to raise the event
public event PropertyChangedEventHandler PropertyChanged;
public void NotifyPropertyChanged(string name)
{
if (PropertyChanged != null)
{
PropertyChanged(this,new PropertyChangedEventArgs(name));
}
}
and it works B)