c# - 使用 ResizeGrip 调整大小时，窗口的 MinWidth 和 MinHeight 都被忽略

Question

首先是窗口本身的 XAML 代码:

<!-- Window Main -->
<Window
    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" mc:Ignorable="d" x:Name="Window_Main" x:Class="WPF_Test.General_Window"
    Title="General_Window" Height="500" Width="1000" BorderThickness="30"  ResizeMode="CanResizeWithGrip" AllowsTransparency="True" WindowStyle="None" StateChanged="Window_Main_StateChanged">
<!-- Effects -->
<Window.Effect>
    <DropShadowEffect x:Name="Border_Effect" ShadowDepth="0" BlurRadius="30" Direction="0" Opacity="0.5"/>
</Window.Effect>
<!-- Border Main -->
<Border x:Name="Border_Main" BorderBrush="Gray" BorderThickness="1">
    <!-- Panel Main -->
    <DockPanel x:Name="Panel_Main">
        <DockPanel x:Name="Panel_Title" Height="25" LastChildFill="False" Background="#FFEEEEEE" MouseDown="Panel_Title_MouseDown" VerticalAlignment="Top" DockPanel.Dock="Top">

        </DockPanel>
        <DockPanel x:Name="Panel_Secondary" LastChildFill="true" Background="#FFEEEEEE"/>
    </DockPanel>
</Border>

这是该窗口的构造函数的 C# 代码，我在其中明确定义了窗口的最小尺寸，但在调整大小时它们仍然被忽略:

public void Window_Init()
    {

        Window_Main.MinHeight = Window_Minimum_Height + Window_Thickness * 2;
        Window_Main.MinWidth = Window_Minimum_Width + Window_Thickness * 2;
        Window_Main.BorderThickness = new Thickness( Window_Thickness );
    }

因此，当我使用 ResizeGrip(由 CanResizeWithGrip 属性提供)调整窗口大小时，窗口本身将停止调整大小它将达到最小宽度和高度。虽然包含整个窗口的渲染区域仍然可以调整到更小的尺寸，因此它看起来像桌面上窗口的截取图像。

Answer 1

我已经解决了这个错误。您可以使用 grip resizer 或创建您自己的调整大小控件，使用 OnMouseDown 事件向 HWND 发送消息以调整窗口大小，但它不会超过您设置的最小尺寸先前已为窗口定义。此代码还将在最大化 时限制窗口大小，以确保窗口永远不会超出屏幕或呈现在任务栏上。

这应该在您的 MainWindow.cs 代码的底部:

        private const int WM_SYSCOMMAND = 0X112;
    private HwndSource hwndSource;
    enum SWP : uint
    {
        NOSIZE = 0x0001 ,
        NOMOVE = 0x0002 ,
        NOZORDER = 0x0004 ,
        NOREDRAW = 0x0008 ,
        NOACTIVATE = 0x0010 ,
        FRAMECHANGED = 0x0020 ,  
        SHOWWINDOW = 0x0040 ,
        HIDEWINDOW = 0x0080 ,
        NOCOPYBITS = 0x0100 ,
        NOOWNERZORDER = 0x0200 , 
        NOSENDCHANGING = 0x0400 , 
    }
    public override void OnApplyTemplate()
    {
        System.IntPtr handle = ( new WindowInteropHelper( this ) ).Handle;
        HwndSource.FromHwnd( handle ).AddHook( new HwndSourceHook( WindowProc ) );
    }
    private System.IntPtr WindowProc( System.IntPtr hwnd , int msg , System.IntPtr wParam , System.IntPtr lParam , ref bool handled )
    {
        switch ( msg )
        {
            case 0x0024:
                {
                    WmGetMinMaxInfo( hwnd , lParam );
                    handled = true;
                    break;
                }
            case 0x0046:
                {
                    WINDOWPOS pos = ( WINDOWPOS )Marshal.PtrToStructure( lParam , typeof( WINDOWPOS ) );
                    if ( ( pos.flags & ( int )(SWP.NOMOVE) ) != 0 )
                    {
                        return IntPtr.Zero;
                    }

                    Window wnd = ( Window )HwndSource.FromHwnd( hwnd ).RootVisual;
                    if ( wnd == null )
                    {
                        return IntPtr.Zero;
                    }

                    bool changedPos = false;
                    if ( pos.cx < MinWidth ) { pos.cx = (int)MinWidth; changedPos = true; }
                    if ( pos.cy < MinHeight ) { pos.cy = ( int )MinHeight; changedPos = true; }
                    if ( !changedPos )
                    {
                        return IntPtr.Zero;
                    }

                    Marshal.StructureToPtr( pos , lParam , true );
                    handled = true;
                    break;
                }
        }
        return ( System.IntPtr )0;
    }
    private void WmGetMinMaxInfo( System.IntPtr hwnd , System.IntPtr lParam )
    {
        MINMAXINFO mmi = ( MINMAXINFO )Marshal.PtrToStructure( lParam , typeof( MINMAXINFO ) );
        int MONITOR_DEFAULTTONEAREST = 0x00000002;
        System.IntPtr monitor = MonitorFromWindow( hwnd , MONITOR_DEFAULTTONEAREST );
        if ( monitor != System.IntPtr.Zero )
        {
            MONITORINFO monitorInfo = new MONITORINFO();
            GetMonitorInfo( monitor , monitorInfo );
            RECT rcWorkArea = monitorInfo.rcWork;
            RECT rcMonitorArea = monitorInfo.rcMonitor;
            mmi.ptMaxPosition.x = Math.Abs( rcWorkArea.left - rcMonitorArea.left );
            mmi.ptMaxPosition.y = Math.Abs( rcWorkArea.top - rcMonitorArea.top );
            mmi.ptMaxSize.x = Math.Abs( rcWorkArea.right - rcWorkArea.left );
            mmi.ptMaxSize.y = Math.Abs( rcWorkArea.bottom - rcWorkArea.top );
        }
        Marshal.StructureToPtr( mmi , lParam , true );
    }
    [StructLayout( LayoutKind.Sequential )]
    public struct POINT
    {
        public int x;
        public int y;
        public POINT( int x , int y )
        {
            this.x = x;
            this.y = y;
        }
    }
    [StructLayout( LayoutKind.Sequential )]
    public struct MINMAXINFO
    {
        public POINT ptReserved;
        public POINT ptMaxSize;
        public POINT ptMaxPosition;
        public POINT ptMinTrackSize;
        public POINT ptMaxTrackSize;
    };
    [StructLayout( LayoutKind.Sequential , CharSet = CharSet.Auto )]
    public class MONITORINFO
    {
        public int cbSize = Marshal.SizeOf( typeof( MONITORINFO ) );
        public RECT rcMonitor = new RECT();
        public RECT rcWork = new RECT();
        public int dwFlags = 0;
    }
    [StructLayout( LayoutKind.Sequential , Pack = 0 )]
    public struct RECT
    {
        public int left;
        public int top;
        public int right;
        public int bottom;
        public static readonly RECT Empty = new RECT();
        public int Width
        {
            get { return Math.Abs( right - left ); }
        }
        public int Height
        {
            get { return bottom - top; }
        }
        public RECT( int left , int top , int right , int bottom )
        {
            this.left = left;
            this.top = top;
            this.right = right;
            this.bottom = bottom;
        }
        public RECT( RECT rcSrc )
        {
            this.left = rcSrc.left;
            this.top = rcSrc.top;
            this.right = rcSrc.right;
            this.bottom = rcSrc.bottom;
        }
        public bool IsEmpty
        {
            get
            {
                return left >= right || top >= bottom;
            }
        }
        public override string ToString()
        {
            if ( this == RECT.Empty ) { return "RECT {Empty}"; }
            return "RECT { left : " + left + " / top : " + top + " / right : " + right + " / bottom : " + bottom + " }";
        }
        public override bool Equals( object obj )
        {
            if ( !( obj is Rect ) ) { return false; }
            return ( this == ( RECT )obj );
        }
        public override int GetHashCode()
        {
            return left.GetHashCode() + top.GetHashCode() + right.GetHashCode() + bottom.GetHashCode();
        }
        public static bool operator ==( RECT rect1 , RECT rect2 )
        {
            return ( rect1.left == rect2.left && rect1.top == rect2.top && rect1.right == rect2.right && rect1.bottom == rect2.bottom );
        }
        public static bool operator !=( RECT rect1 , RECT rect2 )
        {
            return !( rect1 == rect2 );
        }
    }
    [DllImport( "user32" )]
    internal static extern bool GetMonitorInfo( IntPtr hMonitor , MONITORINFO lpmi );
    [DllImport( "User32" )]
    internal static extern IntPtr MonitorFromWindow( IntPtr handle , int flags );
    [StructLayout( LayoutKind.Sequential )]
    internal struct WINDOWPOS
    {
        public IntPtr hwnd;
        public IntPtr hwndInsertAfter;
        public int x;
        public int y;
        public int cx;
        public int cy;
        public int flags;
    }
    private void InitializeWindowSource( object sender , EventArgs e )
    {
        hwndSource = PresentationSource.FromVisual( ( Visual )sender ) as HwndSource;
    }
    public enum ResizeDirection
    {
        Left = 1 ,
        Right = 2 ,
        Top = 3 ,
        TopLeft = 4 ,
        TopRight = 5 ,
        Bottom = 6 ,
        BottomLeft = 7 ,
        BottomRight = 8 ,
    }
    [DllImport( "user32" , CharSet = CharSet.Auto )]
    private static extern IntPtr SendMessage( IntPtr hWnd , uint Msg , IntPtr wParam , IntPtr lParam );
    private void ResizeWindow( ResizeDirection direction )
    {
        SendMessage( hwndSource.Handle , WM_SYSCOMMAND , ( IntPtr )( 61440 + direction ) , IntPtr.Zero );

    }

并且不要忘记将这一行添加到窗口的构造函数中，否则什么都不起作用:

SourceInitialized += new EventHandler( InitializeWindowSource );