How to maximize window without hiding windows taskbar

Question

I use the following code to maximize the WPF window. The problem is that the Windows taskbar is hidden.

        if (this.WindowState == WindowState.Normal)
        {
            this.WindowState = WindowState.Maximized;
        }
        else if (this.WindowState == WindowState.Maximized)
        {
            this.WindowState = WindowState.Normal;
        }

with the following additional code the problem is solved for one monitor. When using multiple monitors, the window is maximized to the size of the main monitor?

this.MaxHeight = SystemParameters.MaximizedPrimaryScreenHeight;

Is there a way to maximize the window to the current monitor in use?

Answer 1

Hi Sarah,
I cannot reproduce your problem with following code:

XAML:

<Window x:Class="WpfApp1.Window008"  
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"  
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"  
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"  
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"  
        xmlns:local="clr-namespace:WpfApp008"  
        mc:Ignorable="d"  
        Title="Window008" Height="450" Width="800"  
        local:ViewModel.AttProp="True">  
  <Window.DataContext>  
    <local:ViewModel/>  
  </Window.DataContext>  
    <StackPanel>  
    <Button Content="Change" Command="{Binding}" Width="200"/>  
  </StackPanel>  
</Window>  

ViewModel:

using System;  
using System.Windows;  
using System.Windows.Input;  
  
namespace WpfApp008  
{  
  public class ViewModel : ICommand  
  {  
    public Window Wnd;  
    public event EventHandler? CanExecuteChanged;  
    public bool CanExecute(object? parameter) => true;  
    public void Execute(object? parameter)  
    {  
      if (Wnd == null) return;  
      if (Wnd.WindowState == WindowState.Normal) Wnd.WindowState = WindowState.Maximized;  
      else if (Wnd.WindowState == WindowState.Maximized) Wnd.WindowState = WindowState.Normal;  
    }  
  
    #region attached property  
    public static readonly DependencyProperty AttPropProperty =  
        DependencyProperty.RegisterAttached("AttProp", typeof(bool), typeof(ViewModel), new PropertyMetadata(false, OnPropChanged));  
    public static bool GetAttProp(DependencyObject obj) => (bool)obj.GetValue(AttPropProperty);  
    public static void SetAttProp(DependencyObject obj, bool par) => obj.SetValue(AttPropProperty, par);  
    private static void OnPropChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)  
    {  
      Window w = d as Window;  
      if (w == null) return;  
      w.Loaded += (s, mbe) => ((ViewModel)(w.DataContext)).Wnd = w;  
    }  
    #endregion  
  }  
}  

Result: