Data binding notes updated

Author: vivekkpatel

docs/WPF/3 DataBind.md

@@ -1,4 +1,56 @@
-### Text Property 
+### Databinding
+- For Databinding you have to implement INotifyPropertyChanged interface
+- Which contain PropertyChangedEventHandler, which we can trigger everytime we update our property
+
+### Sample Code
 ```xml
-Text="{Binding ApplicationName,RelativeSource={RelativeSourceAncestorType=Window}}"
+Title="Test" Height="250" Width="300">
+<Grid>
+    <Grid.RowDefinitions>
+        <RowDefinition/>
+        <RowDefinition/>
+        <RowDefinition/>
+        <RowDefinition/>
+    </Grid.RowDefinitions>
+    <TextBox Grid.Row="0" Name="NameTextBox" Height="40" Width="250" Text="{Binding ClientName,UpdateSourceTrigger=PropertyChanged}"/>
+    <Button Grid.Row="1" Name="SubmitButton" Height="40" Width="100" Content="Submit" Click="SubmitButton_Click"/>
+    <TextBlock Grid.Row="2" Name="ResultTextBlock" Height="40" Width="250" Text="{Binding ClientName}"/>
+    <Button Grid.Row="3" Name="UpdateButton" Height="40" Width="100" Content="Update Name" Click="UpdateNameButton_Click"/>
+</Grid>
+```
+```csharp
+ public partial class Test : Window, INotifyPropertyChanged
+ {
+     public Test()
+     {
+         DataContext = this;
+         InitializeComponent();
+     }
+
+     private string _name = string.Empty;
+     public string ClientName
+     {
+         get { return _name; }
+         set
+         {
+             _name = value;
+             OnPropertyChanged(nameof(ClientName));
+         }
+     }
+
+     public event PropertyChangedEventHandler PropertyChanged;
+
+     protected virtual void OnPropertyChanged(string propertyName)
+     {
+         PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+     }
+     private void SubmitButton_Click(object sender, RoutedEventArgs e)
+     {
+         MessageBox.Show($"Hello, {ClientName}!");
+     }
+     private void UpdateNameButton_Click(object sender, RoutedEventArgs e)
+     {
+         ClientName = "Nodes Automations";
+     }
+ }
 ```