The PasswordBox element in XAML represents a WPF PasswordBox. A PasswordBox is used to handle passwords in WPF. 
The MaxLength property is used to set maximum length of a password. PasswordChar property represents the character used to hide the password and PasswordChanged event is fired when a password is changed.
The following code snippet creates a PasswordBox in WPF using C#.
<PasswordBox Width="250"
Height="30"
                  Background="LightSalmon"
                  Name="pwdBox"
                  MaxLength="64"
                  PasswordChar="#"
                  PasswordChanged="pwdBox_PasswordChanged"  
        />
Here is the PasswordChanged event handler.
private void pwdBox_PasswordChanged(object
sender, RoutedEventArgs e)
{
 
}