我从WPF看到了一些奇怪的行为。我有一个带有三个按钮的表格。一个按钮应该使窗口全屏，一个应该将它放在显示器当前打开的位置，第三个按钮应该将窗口恢复到正常位置。
XAML
<Window x:Class="TestRestore.MainWindow"
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:TestRestore"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525" ResizeMode="CanResizeWithGrip" WindowStartupLocation="CenterScreen">
<Grid>
<Button Content="Max" HorizontalAlignment="Left" Margin="10,10,0,0" VerticalAlignment="Top" Width="94" Click="max_click" Name="max_button"/>
<Button Content="Center" HorizontalAlignment="Left" Margin="10,35,0,0" VerticalAlignment="Top" Width="94" Click="center_click" Name="center_button"/>
<Button Content="Restore" HorizontalAlignment="Left" Margin="227,143,0,0" VerticalAlignment="Top" Width="75" Click="restore_click" Name="restore_button" IsEnabled="False"/>
</Grid>
</Window>
，代码如下。奇怪的行为是，当我最大化，然后恢复窗口时，位置被正确恢复，但窗口仍然认为它已经最大化（最大化按钮看起来像一个恢复按钮，你不能调整窗口大小即使ResizeMode已设置为CanResizeWithGrip）。
当最大化窗口已经恢复时，即使窗口位置没有最大化，它仍认为它仍然最大化，只需通过拖动标题栏手动移动窗口就足以使其自身恢复为非 - 最大化模式。
此外，如果我最大化然后恢复窗口然后再次最大化它而不移动它，最大化的窗口位置是不正确的（不在左上角）。
这个谜团加深了。如果我最大化然后恢复窗口，然后按alt，然后按下（以获取窗口菜单）并选择＆＃39; Move＆＃39;然后用键盘移动窗口，它仍然停留在“伪造的模式”模式中。即使窗口正在被移动，所以看起来解开它的唯一方法就是用鼠标移动它。
using System;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Interop;
namespace TestRestore
{
public partial class MainWindow : Window
{
WindowStyle old_window_style;
WindowState old_window_state;
double old_left;
double old_top;
double old_width;
double old_height;
public MainWindow()
{
InitializeComponent();
}
// remember position, style and state
private void SaveWindowPos()
{
old_window_style = WindowStyle;
old_window_state = WindowState;
old_left = Left;
old_top = Top;
old_width = Width;
old_height = Height;
max_button.IsEnabled = false;
center_button.IsEnabled = false;
restore_button.IsEnabled = true;
}
// put position, style and state back
private void RestoreWindowPos()
{
WindowStyle = old_window_style;
WindowState = old_window_state;
ResizeMode = ResizeMode.CanResizeWithGrip;
Left = old_left;
Top = old_top;
Width = old_width;
Height = old_height;
max_button.IsEnabled = true;
center_button.IsEnabled = true;
restore_button.IsEnabled = false;
}
// make it centered or fullscreen
private void SetActivePos(bool full_screen)
{
SaveWindowPos();
Hide();
if (full_screen)
{
ResizeMode = ResizeMode.NoResize;
WindowStyle = WindowStyle.None;
WindowState = WindowState.Maximized;
}
else
{
Size s = new Size(800, 600);
Point p = CenterRectInMonitor(this, s);
Left = p.X;
Top = p.Y;
Width = s.Width;
Height = s.Height;
ResizeMode = ResizeMode.NoResize;
WindowState = WindowState.Normal;
}
Show();
}
private void restore_click(object sender, RoutedEventArgs e)
{
Hide();
RestoreWindowPos();
Show();
}
private void max_click(object sender, RoutedEventArgs e)
{
SetActivePos(true);
}
private void center_click(object sender, RoutedEventArgs e)
{
SetActivePos(false);
}
// interop
public const Int32 MONITOR_DEFAULTTOPRIMARY = 0x00000001;
public const Int32 MONITOR_DEFAULTTONEAREST = 0x00000002;
[DllImport("user32.dll")]
public static extern IntPtr MonitorFromWindow(IntPtr handle, Int32 flags);
[DllImport("user32.dll", CharSet = CharSet.Auto)]
public static extern bool GetMonitorInfo(IntPtr hMonitor, ref MonitorInfoEx lpmi);
// size of a device name string
private const int CCHDEVICENAME = 32;
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
public struct MonitorInfoEx
{
public int Size;
public RectStruct Monitor;
public RectStruct WorkArea;
public uint Flags;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = CCHDEVICENAME)]
public string DeviceName;
public void Init()
{
this.Size = 40 + 2 * CCHDEVICENAME;
this.DeviceName = string.Empty;
}
}
[StructLayout(LayoutKind.Sequential)]
public struct RectStruct
{
public int Left;
public int Top;
public int Right;
public int Bottom;
public int Width
{
get
{
return Right - Left;
}
}
public int Height
{
get
{
return Bottom - Top;
}
}
}
public static MonitorInfoEx GetMonitorFromWindow(Window w)
{
var hwnd = new WindowInteropHelper(w).EnsureHandle();
var monitor = MonitorFromWindow(hwnd, MONITOR_DEFAULTTONEAREST);
MonitorInfoEx monitor_info = new MonitorInfoEx();
monitor_info.Init();
GetMonitorInfo(monitor, ref monitor_info);
return monitor_info;
}
// work out how a rect of 'Size size' should be centered on the monitor containing 'Window w'
public static Point CenterRectInMonitor(Window w, Size size)
{
var source = PresentationSource.FromVisual(w);
double x_scale = source.CompositionTarget.TransformToDevice.M11;
double y_scale = source.CompositionTarget.TransformToDevice.M22;
var width = size.Width * x_scale;
var height = size.Height * y_scale;
var monitor_info = GetMonitorFromWindow(w);
Size s = new Size(monitor_info.Monitor.Width, monitor_info.Monitor.Height);
Point p = new Point(monitor_info.Monitor.Left, monitor_info.Monitor.Top);
Point c = new Point(p.X + s.Width / 2, p.Y + s.Height / 2);
return new Point((c.X - width / 2) / x_scale, (c.Y - height / 2) / y_scale);
}
}
}
答案 0 :(得分：0)
我没有完整的答案。但是，一旦删除Hide（）和Show（）调用，您会发现代码开始运行得更好。
private void restore_click(object sender, RoutedEventArgs e)
{
// Hide();
RestoreWindowPos();
// Show();
}
我确定你把它放入以减少闪烁，但我认为正在发生的是Hide（）和Show（）调用正在翻转底层OS窗口的窗口样式字中的WS_VISIBLE位，即包含WS_MAXIMIZE和WS_BORDER的相同单词以及您正在操作的其他一些内容。见https://msdn.microsoft.com/en-us/library/windows/desktop/ms632600(v=vs.85).aspx
需要更多的研究来弄清楚究竟发生了什么，但我认为根本问题是“漏洞抽象”。您的代码将top，left，style和state设置为独立的非耦合变量。但他们不是！要设置为left，必须调用OS SetWindowPos（）函数，该函数不需要左上角坐标，窗口大小，Z顺序以及可见性标志以及窗口是否最大化！见https://msdn.microsoft.com/en-us/library/windows/desktop/ms633545(v=vs.85).aspx。因此，每次设置其中一个“独立”变量时，您都会碰到SetWindowPos（）。这个API调用可以追溯到CPU周期非常宝贵的旧时代，您需要在每个API调用中尽可能多地打包功能。
具有讽刺意味的是，这会使您的代码效率低下。我认为要解决这个问题的方法是绕过System.Windows.Window的泄漏抽象，并直接从user32.dll调用SetWindowPos和其他API函数。然后事情会更加可预测。