说起WPF来，除了总所周知的图形处理核心的变化外，和Winform比起来，还有一个巨大的变革，那就是真正意义上做到了界面设计和代码设计的分离。这样可以让美工和程序分开进行，而不是糅合在一块，这样做的好处当然也是显而易见的：提高了开发效率。

原先的设计方式

在我们之前设计的代码中，每当添加一个新的窗体的时候，我总是会在这个新的窗体的XAML文件中加入如下的代码，以便使样式能够应用上去：

然后，在后台中，为了使窗体能够在最大化时不遮蔽任务栏，拖拉窗体边缘能够改变窗口大小，点按窗体可以实现拖拉的时候，在后台加入了如下的代码：

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Windows;using System.Windows.Controls;using System.Windows.Data;using System.Windows.Documents;using System.Windows.Input;using System.Windows.Media;using System.Windows.Media.Imaging;using System.Windows.Shapes;using System.Windows.Interop;using System.Diagnostics;using System.Runtime.InteropServices;namespace WpfApplication1{    /// 
    /// Interaction logic for TestWindow.xaml    /// 
    public partial class MsgWindow : Window    {        private const int WM_SYSCOMMAND = 0x112;        private HwndSource hs;        IntPtr retInt = IntPtr.Zero;        public MsgWindow()        {            InitializeComponent();            this.SourceInitialized += new EventHandler(WSInitialized);        }        void WSInitialized(object sender, EventArgs e)        {            hs = PresentationSource.FromVisual(this) as HwndSource;            hs.AddHook(new HwndSourceHook(WndProc));        }       public double relativeClip = 10;        public enum ResizeDirection        {            Left = 1,            Right = 2,            Top = 3,            TopLeft = 4,            TopRight = 5,            Bottom = 6,            BottomLeft = 7,            BottomRight = 8,        }        [DllImport("user32.dll", CharSet = CharSet.Auto)]        private static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);        private void ResizeWindow(ResizeDirection direction)        {            SendMessage(hs.Handle, WM_SYSCOMMAND, (IntPtr)(61440 + direction), IntPtr.Zero);        }        private void ResetCursor(object sender, MouseEventArgs e)        {            if (Mouse.LeftButton != MouseButtonState.Pressed)            {                this.Cursor = Cursors.Arrow;            }        }        private void Resize(object sender, MouseButtonEventArgs e)        {            Border clickedBorder = sender as Border;            Point pos = Mouse.GetPosition(this);            double x = pos.X;            double y = pos.Y;            double w = this.ActualWidth;            double h = this.ActualHeight;            if (x <= relativeClip & y <= relativeClip) // left top            {                this.Cursor = Cursors.SizeNWSE;                ResizeWindow(ResizeDirection.TopLeft);            }            if (x >= w - relativeClip & y <= relativeClip) //right top            {                this.Cursor = Cursors.SizeNESW;                ResizeWindow(ResizeDirection.TopRight);            }            if (x >= w - relativeClip & y >= h - relativeClip) //bottom right            {                this.Cursor = Cursors.SizeNWSE;                ResizeWindow(ResizeDirection.BottomRight);            }            if (x <= relativeClip & y >= h - relativeClip)  // bottom left            {                this.Cursor = Cursors.SizeNESW;                ResizeWindow(ResizeDirection.BottomLeft);            }            if ((x >= relativeClip & x <= w - relativeClip) & y <= relativeClip) //top            {                this.Cursor = Cursors.SizeNS;                ResizeWindow(ResizeDirection.Top);            }            if (x >= w - relativeClip & (y >= relativeClip & y <= h - relativeClip)) //right            {                this.Cursor = Cursors.SizeWE;                ResizeWindow(ResizeDirection.Right);            }            if ((x >= relativeClip & x <= w - relativeClip) & y > h - relativeClip) //bottom            {                this.Cursor = Cursors.SizeNS;                ResizeWindow(ResizeDirection.Bottom);            }            if (x <= relativeClip & (y <= h - relativeClip & y >= relativeClip)) //left            {                this.Cursor = Cursors.SizeWE;                ResizeWindow(ResizeDirection.Left);            }        }        private void DisplayResizeCursor(object sender, MouseEventArgs e)        {            Border clickBorder = sender as Border;            Point pos = Mouse.GetPosition(this);            double x = pos.X;            double y = pos.Y;            double w= this.ActualWidth;            double h= this.ActualHeight;            this.label1.Content = x + "--" + y;            if (x <= relativeClip & y <= relativeClip) // left top            {                this.Cursor = Cursors.SizeNWSE;            }            if (x >= w - relativeClip & y <= relativeClip) //right top            {                this.Cursor = Cursors.SizeNESW;            }            if (x >= w - relativeClip & y >= h - relativeClip) //bottom right            {                this.Cursor = Cursors.SizeNWSE;            }            if (x <= relativeClip & y >= h - relativeClip)  // bottom left            {                this.Cursor = Cursors.SizeNESW;            }            if ((x >= relativeClip & x <= w - relativeClip) & y <= relativeClip) //top            {                this.Cursor = Cursors.SizeNS;            }            if (x >= w - relativeClip & (y >= relativeClip & y <= h - relativeClip)) //right            {                this.Cursor = Cursors.SizeWE;            }            if ((x >= relativeClip & x <= w - relativeClip) & y > h - relativeClip) //bottom            {                this.Cursor = Cursors.SizeNS;            }            if (x <= relativeClip & (y <= h - relativeClip & y >= relativeClip)) //left            {                this.Cursor = Cursors.SizeWE;            }        }        private void button1_Click(object sender, RoutedEventArgs e)        {            this.WindowState = (this.WindowState == WindowState.Normal ? WindowState.Maximized : WindowState.Normal);        }        #region 这一部分用于最大化时不遮蔽任务栏        private static void WmGetMinMaxInfo(System.IntPtr hwnd, System.IntPtr lParam)        {            MINMAXINFO 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;            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);        }        /// 
        /// POINT aka POINTAPI        /// 
        [StructLayout(LayoutKind.Sequential)]        public struct POINT        {            /// 
            /// x coordinate of point.            /// 
            public int x;            /// 
            /// y coordinate of point.            /// 
            public int y;            /// 
            /// Construct a point of coordinates (x,y).            /// 
            public POINT(int x, int y)            {                this.x = x;                this.y = y;            }        }        /// 
        /// 窗体大小信息        /// 
        [StructLayout(LayoutKind.Sequential)]        public struct MINMAXINFO        {            public POINT ptReserved;            public POINT ptMaxSize;            public POINT ptMaxPosition;            public POINT ptMinTrackSize;            public POINT ptMaxTrackSize;        };        /// 
 Win32 
        [StructLayout(LayoutKind.Sequential, Pack = 0)]        public struct RECT        {            /// 
 Win32 
            public int left;            /// 
 Win32 
            public int top;            /// 
 Win32 
            public int right;            /// 
 Win32 
            public int bottom;            /// 
 Win32 
            public static readonly RECT Empty = new RECT();            /// 
 Win32 
            public int Width            {                get { return Math.Abs(right - left); }  // Abs needed for BIDI OS            }            /// 
 Win32 
            public int Height            {                get { return bottom - top; }            }            /// 
 Win32 
            public RECT(int left, int top, int right, int bottom)            {                this.left = left;                this.top = top;                this.right = right;                this.bottom = bottom;            }            /// 
 Win32 
            public RECT(RECT rcSrc)            {                this.left = rcSrc.left;                this.top = rcSrc.top;                this.right = rcSrc.right;                this.bottom = rcSrc.bottom;            }            /// 
 Win32 
            public bool IsEmpty            {                get                {                    // BUGBUG : On Bidi OS (hebrew arabic) left > right                    return left >= right || top >= bottom;                }            }            /// 
 Return a user friendly representation of this struct 
            public override string ToString()            {                if (this == RECT.Empty) { return "RECT {Empty}"; }                return "RECT { left : " + left + " / top : " + top + " / right : " + right + " / bottom : " + bottom + " }";            }            /// 
 Determine if 2 RECT are equal (deep compare) 
            public override bool Equals(object obj)            {                if (!(obj is Rect)) { return false; }                return (this == (RECT)obj);            }            /// 
Return the HashCode for this struct (not garanteed to be unique)
            public override int GetHashCode()            {                return left.GetHashCode() + top.GetHashCode() + right.GetHashCode() + bottom.GetHashCode();            }            /// 
 Determine if 2 RECT are equal (deep compare)
            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);            }            /// 
 Determine if 2 RECT are different(deep compare)
            public static bool operator !=(RECT rect1, RECT rect2)            {                return !(rect1 == rect2);            }        }        [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;        }        [DllImport("user32")]        internal static extern bool GetMonitorInfo(IntPtr hMonitor, MONITORINFO lpmi);        [DllImport("User32")]        internal static extern IntPtr MonitorFromWindow(IntPtr handle, int flags);        #endregion        private void MyMacClass_SourceInitialized(object sender, EventArgs e)        {            hs = PresentationSource.FromVisual((Visual)sender) as HwndSource;            hs.AddHook(new HwndSourceHook(WndProc));        }        private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)        {            switch (msg)            {                case 0x0024:/* WM_GETMINMAXINFO */                    WmGetMinMaxInfo(hwnd, lParam);                    handled = true;                    break;                default: break;            }            return (System.IntPtr)0;        }    }}

如果按照上面的设计，那么每加入一个新的窗体，都要重复上面的两个步骤的话，加入一个工程中需要加入的新窗体特别多，估计这种操作足以让一个正常人疯掉了。并且假如以后border的颜色要修改，那得修改多少页面啊~~~

改进的设计方式

所以，为了便于设计和维护，实现所谓的UI和代码分析，让我们提出一个假设的方案来：

首先，所有的公共样式放到一个样式文件中，所有新加的窗体都能共享这个公共的样式文件。

其次，所有的公共事件（窗体最大化，最小化，关闭等），都放到一个公共的基类中，所有新加的窗体只要继承该基类，即可继承系统公用的事件操作。

那么，本着这个假设，我们开始来进行。

首先，对于公共样式，我们需要添加一个“资源词典”的页面，用来设计公共样式：

添加完成后，会看到如下XAML：

下面我们在这个文件中添加样式：

好了，这就是我们的样式文件，接下来我们需要处理这个样式中的Border事件，让其支持鼠标左键拖拉功能。

新建一个类，命名为MyThemeClass.cs，让其继承自Window基类。在MyThemeClass类中，我们主要处理两个内容，一个是支持鼠标左键拖拉以便改变窗体大小，另一个是使窗体不遮蔽任务栏。

具体代码如下：

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Windows;using System.Windows.Media;using System.Windows.Interop;using System.Runtime.InteropServices;using System.Windows.Controls;using System.Windows.Input; namespace MyOwnerDrawnWindow{    public class MyThemeClass:Window    {         private const int WM_SYSCOMMAND = 0x112;        public const int WM_LBUTTONUP = 0x0202;        private HwndSource hs;        IntPtr retInt = IntPtr.Zero;        public double relativeClip = 10;         public MyThemeClass()        {            this.Loaded += delegate            {                InitializeEvent();            };            this.SourceInitialized +=new EventHandler(MyMacClass_SourceInitialized);        }         private void MyMacClass_SourceInitialized(object sender, EventArgs e)        {            hs = PresentationSource.FromVisual((Visual)sender) as HwndSource;            hs.AddHook(new HwndSourceHook(WndProc));        }         private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)        {            switch (msg)            {                case 0x0024:/* WM_GETMINMAXINFO */                    WmGetMinMaxInfo(hwnd, lParam);                    handled = true;                    break;                default: break;            }            return (System.IntPtr)0;        }         #region 这一部分用于最大化时不遮蔽任务栏        private static void WmGetMinMaxInfo(System.IntPtr hwnd, System.IntPtr lParam)        {             MINMAXINFO 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;            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);        }         /// 
        /// POINT aka POINTAPI        /// 
        [StructLayout(LayoutKind.Sequential)]        public struct POINT        {            /// 
            /// x coordinate of point.            /// 
            public int x;            /// 
            /// y coordinate of point.            /// 
            public int y;             /// 
            /// Construct a point of coordinates (x,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, Pack = 0)]        public struct RECT        {            /// 
 Win32 
            public int left;            /// 
 Win32 
            public int top;            /// 
 Win32 
            public int right;            /// 
 Win32 
            public int bottom;             /// 
 Win32 
            public static readonly RECT Empty = new RECT();             /// 
 Win32 
            public int Width            {                get { return Math.Abs(right - left); }  // Abs needed for BIDI OS            }            /// 
 Win32 
            public int Height            {                get { return bottom - top; }            }             /// 
 Win32 
            public RECT(int left, int top, int right, int bottom)            {                this.left = left;                this.top = top;                this.right = right;                this.bottom = bottom;            }              /// 
 Win32 
            public RECT(RECT rcSrc)            {                this.left = rcSrc.left;                this.top = rcSrc.top;                this.right = rcSrc.right;                this.bottom = rcSrc.bottom;            }        }         [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;        }         [DllImport("user32")]        internal static extern bool GetMonitorInfo(IntPtr hMonitor, MONITORINFO lpmi);         [DllImport("User32")]        internal static extern IntPtr MonitorFromWindow(IntPtr handle, int flags);        #endregion         #region 这一部分是四个边加上四个角        public enum ResizeDirection        {            Left = 1,            Right = 2,            Top = 3,            TopLeft = 4,            TopRight = 5,            Bottom = 6,            BottomLeft = 7,            BottomRight = 8,        }        #endregion         #region 用于改变窗体大小        [DllImport("user32.dll", CharSet = CharSet.Auto)]        private static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);         private void ResizeWindow(ResizeDirection direction)        {            SendMessage(hs.Handle, WM_SYSCOMMAND, (IntPtr)(61440 + direction), IntPtr.Zero);        }        #endregion         #region 为元素注册事件        private void InitializeEvent()        {            ControlTemplate baseWindowTemplate = (ControlTemplate)App.Current.Resources["MyWindowTemplate"];            Border borderClip = (Border)baseWindowTemplate.FindName("MyBorder", this);             borderClip.MouseMove += delegate            {                DisplayResizeCursor(null,null);            };             borderClip.PreviewMouseDown += delegate            {                Resize(null,null);            };             borderClip.MouseLeftButtonDown += delegate            {                DragMove();            };             this.PreviewMouseMove += delegate            {                ResetCursor(null,null);            };        }        #endregion         #region 重写的DragMove，以便解决利用系统自带的DragMove出现Exception的情况        public new void DragMove()        {            if (this.WindowState == WindowState.Normal)            {                SendMessage(hs.Handle, WM_SYSCOMMAND, (IntPtr)0xf012, IntPtr.Zero);                SendMessage(hs.Handle, WM_LBUTTONUP, IntPtr.Zero, IntPtr.Zero);            }        }        #endregion         #region 显示拖拉鼠标形状        private void DisplayResizeCursor(object sender, MouseEventArgs e)        {            Point pos = Mouse.GetPosition(this);            double x = pos.X;            double y = pos.Y;            double w = this.ActualWidth;  //注意这个地方使用ActualWidth,才能够实时显示宽度变化            double h = this.ActualHeight;             if (x <= relativeClip & y <= relativeClip) // left top            {                this.Cursor = Cursors.SizeNWSE;            }            if (x >= w - relativeClip & y <= relativeClip) //right top            {                this.Cursor = Cursors.SizeNESW;            }             if (x >= w - relativeClip & y >= h - relativeClip) //bottom right            {                this.Cursor = Cursors.SizeNWSE;            }             if (x <= relativeClip & y >= h - relativeClip)  // bottom left            {                this.Cursor = Cursors.SizeNESW;            }             if ((x >= relativeClip & x <= w - relativeClip) & y <= relativeClip) //top            {                this.Cursor = Cursors.SizeNS;            }             if (x >= w - relativeClip & (y >= relativeClip & y <= h - relativeClip)) //right            {                this.Cursor = Cursors.SizeWE;            }             if ((x >= relativeClip & x <= w - relativeClip) & y > h - relativeClip) //bottom            {                this.Cursor = Cursors.SizeNS;            }             if (x <= relativeClip & (y <= h - relativeClip & y >= relativeClip)) //left            {                this.Cursor = Cursors.SizeWE;            }        }        #endregion         #region  还原鼠标形状        private void ResetCursor(object sender, MouseEventArgs e)        {            if (Mouse.LeftButton != MouseButtonState.Pressed)            {                this.Cursor = Cursors.Arrow;            }        }        #endregion         #region 判断区域，改变窗体大小        private void Resize(object sender, MouseButtonEventArgs e)        {            Point pos = Mouse.GetPosition(this);            double x = pos.X;            double y = pos.Y;            double w = this.ActualWidth;            double h = this.ActualHeight;             if (x <= relativeClip & y <= relativeClip) // left top            {                this.Cursor = Cursors.SizeNWSE;                ResizeWindow(ResizeDirection.TopLeft);            }            if (x >= w - relativeClip & y <= relativeClip) //right top            {                this.Cursor = Cursors.SizeNESW;                ResizeWindow(ResizeDirection.TopRight);            }             if (x >= w - relativeClip & y >= h - relativeClip) //bottom right            {                this.Cursor = Cursors.SizeNWSE;                ResizeWindow(ResizeDirection.BottomRight);            }             if (x <= relativeClip & y >= h - relativeClip)  // bottom left            {                this.Cursor = Cursors.SizeNESW;                ResizeWindow(ResizeDirection.BottomLeft);            }             if ((x >= relativeClip & x <= w - relativeClip) & y <= relativeClip) //top            {                this.Cursor = Cursors.SizeNS;                ResizeWindow(ResizeDirection.Top);            }             if (x >= w - relativeClip & (y >= relativeClip & y <= h - relativeClip)) //right            {                this.Cursor = Cursors.SizeWE;                ResizeWindow(ResizeDirection.Right);            }             if ((x >= relativeClip & x <= w - relativeClip) & y > h - relativeClip) //bottom            {                this.Cursor = Cursors.SizeNS;                ResizeWindow(ResizeDirection.Bottom);            }             if (x <= relativeClip & (y <= h - relativeClip & y >= relativeClip)) //left            {                this.Cursor = Cursors.SizeWE;                ResizeWindow(ResizeDirection.Left);            }        }        #endregion    }}

这样，我们的Theme和类就创建好了，那么，在主窗体中，我们该如何应用上去呢？当然，这个不是难事，并且异常简单：

首先，创建一个新的窗体Window1, 它需要继承自MyThemeClass类：

public partial class Window1 : MyThemeClass

然后再XAML中只需要修改两个地方，首先是添加入一个新的引用：

xmlns:src="clr-namespace:MyOwnerDrawnWindow"

添加完这个引用后，把<Window….></Window>修改成<src:MyThemeClass……></ MyThemeClass> 这样做的目的是防止由于继承基类的不同而造成XAML的识别错误。

最后，只需要添加这句Style="{StaticResource MyWindowStyle}"  就行了。 这样就算是添加完成了新的窗体，每一个新添加的窗体都按照这种方式添加即可，是不是简洁了许多？ 并且后期维护也简单多了。

好了，最后一步就是讲Theme文件关联起来，在APP.xaml文件中添加对资源文件的引用即可：

这样运行起来以后，达到的预期的效果。

源码下载