There are no built-in properties to display the password character in the PasswordBox control. But we can do this with a TextBox control to display the password in the PasswordBox. For PasswordBox with show / hide function in WPF. We will be using two TextBlock controls, TextBox control, PasswordBox control, Image control

XAML

<Grid>
    <TextBlock Text="Welcome&#xa;To see the Password"
               FontSize="28"
               FontWeight="Bold"
               HorizontalAlignment="Center"
               VerticalAlignment="Top"
               TextAlignment="Center"
               Margin="0,30,0,0" />
    <TextBlock Text="Enter your password"
               FontSize="20"
               HorizontalAlignment="Left"
               Margin="112,160,0,0"
               VerticalAlignment="Top" />
    <TextBox Height="40"
             FontSize="20"
             Padding="5,2,47,0"
             HorizontalAlignment="Left"
             Margin="112,193,0,0"
             Name="txtVisiblePasswordbox"
             VerticalAlignment="Top"
             Width="274" />
    <PasswordBox Height="40"
                 FontSize="20"
                 Padding="5,2,47,0" 
                 HorizontalAlignment="Left"
                 Margin="112,193,0,0"
                 Name="txtPasswordbox"
                 VerticalAlignment="Top"
                 Width="274"
                 PasswordChanged="txtPasswordbox_PasswordChanged" />
    <Image Visibility="Hidden"
           Height="30"
           HorizontalAlignment="Left"
           Name="ImgShowHide"
           Stretch="Fill"
           VerticalAlignment="Top"
           Width="30"
           Margin="351,198,0,0"
           MouseLeave="ImgShowHide_MouseLeave"
           PreviewMouseDown="ImgShowHide_PreviewMouseDown"
           PreviewMouseUp="ImgShowHide_PreviewMouseUp" />
</Grid>

      

        
        
        
      

    

Code for

string AppPath = Directory.GetCurrentDirectory();
public MainWindow()
{
    InitializeComponent();
    ImgShowHide.Source = new BitmapImage(new Uri(AppPath + "\\img\\clip.jpg"));
}
private void ImgShowHide_PreviewMouseUp(object sender, MouseButtonEventArgs e)
{
    HidePassword();
}

private void ImgShowHide_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
    ShowPassword();
}
private void ImgShowHide_MouseLeave(object sender, MouseEventArgs e)
{
    HidePassword();
}
private void txtPasswordbox_PasswordChanged(object sender, RoutedEventArgs e)
{
    if(txtPasswordbox.Password.Length > 0)
        ImgShowHide.Visibility = Visibility.Visible;
    else
        ImgShowHide.Visibility = Visibility.Hidden;
}

void ShowPassword()
{
    ImgShowHide.Source = new BitmapImage(new Uri(AppPath + "\\img\\cus.jpg"));
    txtVisiblePasswordbox.Visibility = Visibility.Visible;
    txtPasswordbox.Visibility = Visibility.Hidden;
    txtVisiblePasswordbox.Text = txtPasswordbox.Password;
}
void HidePassword()
{
    ImgShowHide.Source = new BitmapImage(new Uri(AppPath + "\\img\\clip.jpg"));
    txtVisiblePasswordbox.Visibility = Visibility.Hidden;
    txtPasswordbox.Visibility = Visibility.Visible;
    txtPasswordbox.Focus();
}