要设置的属性是=> WindowStyle="None"

<Window x:Class="mdaframework.MainWindow"
            xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
            xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
            Title="Start" Height="350" Width="525" ResizeMode="NoResize"  WindowStartupLocation="CenterScreen" WindowStyle="None">

要禁用关闭按钮，你应该添加以下代码到你的Window类(代码是从这里，编辑和重新格式化一点):

protected override void OnSourceInitialized(EventArgs e)
{
    base.OnSourceInitialized(e);

    HwndSource hwndSource = PresentationSource.FromVisual(this) as HwndSource;

    if (hwndSource != null)
    {
        hwndSource.AddHook(HwndSourceHook);
    }

}

private bool allowClosing = false;

[DllImport("user32.dll")]
private static extern IntPtr GetSystemMenu(IntPtr hWnd, bool bRevert);
[DllImport("user32.dll")]
private static extern bool EnableMenuItem(IntPtr hMenu, uint uIDEnableItem, uint uEnable);

private const uint MF_BYCOMMAND = 0x00000000;
private const uint MF_GRAYED = 0x00000001;

private const uint SC_CLOSE = 0xF060;

private const int WM_SHOWWINDOW = 0x00000018;
private const int WM_CLOSE = 0x10;

private IntPtr HwndSourceHook(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
    switch (msg)
    {
        case WM_SHOWWINDOW:
            {
                IntPtr hMenu = GetSystemMenu(hwnd, false);
                if (hMenu != IntPtr.Zero)
                {
                    EnableMenuItem(hMenu, SC_CLOSE, MF_BYCOMMAND | MF_GRAYED);
                }
            }
            break;
        case WM_CLOSE:
            if (!allowClosing)
            {
                handled = true;
            }
            break;
    }
    return IntPtr.Zero;
}

这段代码还禁用了系统菜单中的关闭项，并禁止使用Alt+F4关闭对话框。

您可能希望以编程方式关闭该窗口。仅仅调用Close()是行不通的。你可以这样做:

allowClosing = true;
Close();

这就是你的问题所在。窗口框右上方的关闭按钮不是WPF窗口的一部分，但它属于由操作系统控制的窗口框的一部分。这意味着你必须使用Win32互操作来实现。

或者，您可以使用noframe并提供您自己的“框架”或根本没有框架。

使用这个，从https://stephenhaunts.com/2014/09/25/remove-the-close-button-from-a-wpf-window修改:

using System;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Input;
using System.Windows.Interop;
using System.Windows.Media;

namespace Whatever
{
    public partial class MainMenu : Window
    {
        private const int GWL_STYLE = -16;
        private const int WS_SYSMENU = 0x00080000;

        [DllImport("user32.dll", SetLastError = true)]
        private static extern int GetWindowLongPtr(IntPtr hWnd, int nIndex);

        [DllImport("user32.dll")]
        private static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);

        public MainMenu()
        {
             InitializeComponent();
             this.Loaded += new RoutedEventHandler(Window_Loaded);
        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            var hwnd = new WindowInteropHelper(this).Handle;
            SetWindowLongPtr(hwnd, GWL_STYLE, GetWindowLongPtr(hwnd, GWL_STYLE) & ~WS_SYSMENU);
        }  

    }
}

XAML 代码

<Button Command="Open" Content="_Open">
    <Button.Style>
        <Style TargetType="Button">
            <Style.Triggers>
                <Trigger Property="IsEnabled" Value="False">
                    <Setter Property="Visibility" Value="Collapsed" />
                </Trigger>
            </Style.Triggers>
        </Style>
     </Button.Style>
</Button>

应该工作

编辑-在你的瞬间，这个线程展示了如何做到这一点，但我不认为窗口有一个属性来获得你想要的而不失去正常的标题栏。

编辑2 这个线程展示了一种方法，但你必须将自己的风格应用到系统菜单，它展示了一种方法，你可以这样做。

我只是使用交互性行为(你需要引用System.Windows.Interactivity)添加了我对Joe White的答案的实现。

代码:

public class HideCloseButtonOnWindow : Behavior<Window>
{
    #region bunch of native methods

    private const int GWL_STYLE = -16;
    private const int WS_SYSMENU = 0x80000;

    [DllImport("user32.dll", SetLastError = true)]
    private static extern int GetWindowLong(IntPtr hWnd, int nIndex);

    [DllImport("user32.dll")]
    private static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);

    #endregion

    protected override void OnAttached()
    {
        base.OnAttached();
        AssociatedObject.Loaded += OnLoaded;
    }

    protected override void OnDetaching()
    {
        AssociatedObject.Loaded -= OnLoaded;
        base.OnDetaching();
    }

    private void OnLoaded(object sender, RoutedEventArgs e)
    {
        var hwnd = new WindowInteropHelper(AssociatedObject).Handle;
        SetWindowLong(hwnd, GWL_STYLE, GetWindowLong(hwnd, GWL_STYLE) & ~WS_SYSMENU);
    }
}

用法:

<Window x:Class="WpfApplication2.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
        xmlns:w="clr-namespace:WpfApplication2">

    <i:Interaction.Behaviors>
        <w:HideCloseButtonOnWindow />
    </i:Interaction.Behaviors>

</Window>