wpf中无边框窗体的问题

无边框窗体最大化显示超出屏幕外的解决方案

相关：
https://stackoverflow.com/questions/12884987/wpf-borderless-window-on-maximize-exceeds-window-height-and-width?rq=1
Solved:
通过修改ResizeMode = ResizeMode.NoResize可以有效的解决该问题，但需要注意的是在其它窗口状态下ResizeMode需要恢复原先值。具体代码如下：

    private ResizeMode _preResizeMode;

    private void BtnMax_OnClick(object sender, RoutedEventArgs e)
    {
        _preResizeMode = this.ResizeMode;
        this.ResizeMode = ResizeMode.NoResize;
        this.WindowState = WindowState.Maximized;
    }

    private void BtnNormax_OnClick(object sender, RoutedEventArgs e)
    {
        this.ResizeMode = _preResizeMode;
        this.WindowState = WindowState.Normal;
    }

    private void BtnMinimal_OnClick(object sender, RoutedEventArgs e)
    {
        this.ResizeMode = _preResizeMode;
        this.WindowState = WindowState.Minimized;
    }

无边框窗体不摭挡桌面工具栏的代码

使用P/Invoke的方式

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Windows;
using System.Windows.Interop;

namespace testxx22
{
    public partial class MainWindow
    {
        void MainWindow_SourceInitialized(object sender, EventArgs e)
        {
            IntPtr handle = (new WindowInteropHelper(this)).Handle;
            HwndSource.FromHwnd(handle).AddHook(WindowProc);
        }

        private static IntPtr WindowProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
        {
            switch (msg)
            {
                case 0x0024:
                    WmGetMinMaxInfo(hwnd, lParam);
                    handled = true;
                    break;
            }

            return (IntPtr)0;
        }

        private static void WmGetMinMaxInfo(IntPtr hwnd, IntPtr lParam)
        {
            var mmi = (MINMAXINFO)Marshal.PtrToStructure(lParam, typeof(MINMAXINFO));

            // Adjust the maximized size and position to fit the work area of the correct monitor
            int MONITOR_DEFAULTTONEAREST = 0x00000002;
            IntPtr monitor = MonitorFromWindow(hwnd, MONITOR_DEFAULTTONEAREST);

            if (monitor != IntPtr.Zero)
            {
                var 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);
                //下两行是用来控制不摭挡工具栏    
                mmi.ptMaxSize.x = Math.Abs(rcWorkArea.right - rcWorkArea.left);
                mmi.ptMaxSize.y = Math.Abs(rcWorkArea.bottom - rcWorkArea.top);
            }

            Marshal.StructureToPtr(mmi, lParam, true);
        }

        /// <summary>
        /// POINT aka POINTAPI
        /// </summary>
        [StructLayout(LayoutKind.Sequential)]
        public struct POINT
        {
            /// <summary>
            /// x coordinate of point.
            /// </summary>
            public int x;
            /// <summary>
            /// y coordinate of point.
            /// </summary>
            public int y;

            /// <summary>
            /// Construct a point of coordinates (x,y).
            /// </summary>
            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;
        };

        /// <summary>
        /// </summary>
        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
        public class MONITORINFO
        {
            /// <summary>
            /// </summary>
            public int cbSize = Marshal.SizeOf(typeof(MONITORINFO));

            /// <summary>
            /// </summary>
            public RECT rcMonitor = new RECT();

            /// <summary>
            /// </summary>
            public RECT rcWork = new RECT();

            /// <summary>
            /// </summary>
            public int dwFlags = 0;
        }

        /// <summary> Win32 </summary>
        [StructLayout(LayoutKind.Sequential, Pack = 0)]
        public struct RECT
        {
            /// <summary> Win32 </summary>
            public int left;
            /// <summary> Win32 </summary>
            public int top;
            /// <summary> Win32 </summary>
            public int right;
            /// <summary> Win32 </summary>
            public int bottom;

            /// <summary> Win32 </summary>
            public static readonly RECT Empty = new RECT();

            /// <summary> Win32 </summary>
            public int Width
            {
                get { return Math.Abs(right - left); }  // Abs needed for BIDI OS
            }
            /// <summary> Win32 </summary>
            public int Height
            {
                get { return bottom - top; }
            }

            /// <summary> Win32 </summary>
            public RECT(int left, int top, int right, int bottom)
            {
                this.left = left;
                this.top = top;
                this.right = right;
                this.bottom = bottom;
            }

            /// <summary> Win32 </summary>
            public RECT(RECT rcSrc)
            {
                this.left = rcSrc.left;
                this.top = rcSrc.top;
                this.right = rcSrc.right;
                this.bottom = rcSrc.bottom;
            }

            /// <summary> Win32 </summary>
            public bool IsEmpty
            {
                get
                {
                    // BUGBUG : On Bidi OS (hebrew arabic) left > right
                    return left >= right || top >= bottom;
                }
            }
            /// <summary> Return a user friendly representation of this struct </summary>
            public override string ToString()
            {
                if (this == RECT.Empty) { return "RECT {Empty}"; }
                return "RECT { left : " + left + " / top : " + top + " / right : " + right + " / bottom : " + bottom + " }";
            }

            /// <summary> Determine if 2 RECT are equal (deep compare) </summary>
            public override bool Equals(object obj)
            {
                if (!(obj is Rect)) { return false; }
                return (this == (RECT)obj);
            }

            /// <summary>Return the HashCode for this struct (not garanteed to be unique)</summary>
            public override int GetHashCode()
            {
                return left.GetHashCode() + top.GetHashCode() + right.GetHashCode() + bottom.GetHashCode();
            }

            /// <summary> Determine if 2 RECT are equal (deep compare)</summary>
            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);
            }

            /// <summary> Determine if 2 RECT are different(deep compare)</summary>
            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);
    }
}

较上一种的精简，不使用P/Invoke，但需要引用System.Windows.Form和System.Drawing

private void win_SourceInitialized(object sender, System.EventArgs e)
        {
            var handle = (new WindowInteropHelper(this)).Handle;
            var handleSource = HwndSource.FromHwnd(handle);
            if (handleSource == null)
                return;
            handleSource.AddHook(WindowProc);
        }

        private static IntPtr WindowProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
        {
            switch (msg)
            {
                case 0x0024: /* WM_GETMINMAXINFO */
                    WmGetMinMaxInfo(hwnd, lParam);
                    handled = true;
                    break;
            }

            return (IntPtr) 0;
        }

        private static void WmGetMinMaxInfo(IntPtr hwnd, IntPtr lParam)
        {

            var mmi = (MINMAXINFO) Marshal.PtrToStructure(lParam, typeof (MINMAXINFO));

            // Adjust the maximized size and position to fit the work area of the correct monitor
            var currentScreen = System.Windows.Forms.Screen.FromHandle(hwnd);
            var workArea = currentScreen.WorkingArea;
            var monitorArea = currentScreen.Bounds;
            mmi.ptMaxPosition.x = Math.Abs(workArea.Left - monitorArea.Left);
            mmi.ptMaxPosition.y = Math.Abs(workArea.Top - monitorArea.Top);
            mmi.ptMaxSize.x = Math.Abs(workArea.Right - workArea.Left);
            mmi.ptMaxSize.y = Math.Abs(workArea.Bottom - workArea.Top);

            Marshal.StructureToPtr(mmi, lParam, true);
        }
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct MINMAXINFO
    {
        public POINT ptReserved;
        public POINT ptMaxSize;
        public POINT ptMaxPosition;
        public POINT ptMinTrackSize;
        public POINT ptMaxTrackSize;
    };

    [StructLayout(LayoutKind.Sequential)]
    public struct POINT
    {
        /// <summary>
        /// x coordinate of point.
        /// </summary>
        public int x;

        /// <summary>
        /// y coordinate of point.
        /// </summary>
        public int y;

        /// <summary>
        /// Construct a point of coordinates (x,y).
        /// </summary>
        public POINT(int x, int y)
        {
            this.x = x;
            this.y = y;
        }
    }