WPF Window Resizing(WindowResizer.dll)改进

谁借莪１个温暖的怀抱￠ 2022-03-26 03:56 131阅读 0赞

[WPF Window Resizing(CodeProject原文)][WPF Window Resizing_CodeProject]

原文中的代码演示了如何动态实时改变WPF窗口的方法,不过在测试中发现一个小问题,即当鼠标按下后一直向一个方向缩小窗口的时候,当鼠标超过了另一条边的时候(在左边框按下,一直向右拖动鼠标,直到鼠标超过右边框时,异常就出现了,其他四个方向同理)会引发异常.

以下代码在原来的基础上,主要修改了updateSize函数,解决了问题.

2013-04-02：新问题，找时间修改

1，当拖动左边框的时候，右边框应固定不动，但现在右边框则在不停的闪动，虽然最后的位置是正确的。同样，上下拖动也存在相同的问题。是因为时时改变了当前窗口的左上角坐标点位置，重绘引起的闪动。

完整代码示例:

[代码下载][Link 1]

以下代码加入了控制窗口最大化的时候不遮盖任务栏  
  
1,加入最小宽度，最小高度的限制  
  
2,限制最大高度不超过屏幕的工作区域，避免向下拖动时，拖动到任务栏以下的区域，被任务栏遮盖。

在窗口的构造函数中调用。

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.Runtime.InteropServices;
    using System.Windows.Interop;
    using System.Threading;
    using System.Windows.Media.Effects;
    
    namespace DNBSoft.WPF
    {
        public class WindowResizer
        {
            private Window target = null;
    
            private bool resizeRight = false;
            private bool resizeLeft = false;
            private bool resizeUp = false;
            private bool resizeDown = false;
    
            private Dictionary<UIElement, short> leftElements = new Dictionary<UIElement, short>();
            private Dictionary<UIElement, short> rightElements = new Dictionary<UIElement, short>();
            private Dictionary<UIElement, short> upElements = new Dictionary<UIElement, short>();
            private Dictionary<UIElement, short> downElements = new Dictionary<UIElement, short>();
    
            private PointAPI startMousePoint = new PointAPI();          //鼠标左键点下时的坐标点
            private Size startWindowSize = new Size();                  //鼠标左键点下时,窗口的大小
            private Point startWindowLeftUpPoint = new Point();         //鼠标左键点下时,窗口左上角坐标点位置
            private static int workAreaMaxHeight = -1;                          //工作区域最大高度
    
            public int minWidth = 10;
            public int minHeight = 10;
    
            private HwndSource hs;
    
            private delegate void RefreshDelegate();
    
            public WindowResizer(Window target)
            {
                this.target = target;
    
                if (target == null)
                {
                    throw new Exception("Invalid Window handle");
                }
    
                //窗口大小发生变化时，及时调整窗口最大高度和宽度，防止遮盖任务栏
                this.target.SourceInitialized += new EventHandler(MyMacClass_SourceInitialized);
            }
    
            #region 这一部分用于最大化时不遮蔽任务栏
    
            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;
            }
    
            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);
    
                    // 这行如果不注释掉在多显示器情况下显示会有问题！ 
                    // mmi.ptMaxSize.x = Math.Abs(rcWorkArea.right - rcWorkArea.left);
                    mmi.ptMaxSize.y = Math.Abs(rcWorkArea.bottom - rcWorkArea.top);
                    workAreaMaxHeight = mmi.ptMaxSize.y;
    
                    //当窗口的任务栏自动隐藏时，最大化的时候最下边要留几个像素的空白，否则此窗口将屏幕铺满，则鼠标移到最下边时，任务栏无法自动弹出
                    if (rcWorkArea.Height == rcMonitorArea.Height)
                    {
                        mmi.ptMaxSize.y -= 2;
                    }
                }
    
                Marshal.StructureToPtr(mmi, lParam, true);
            }
    
            [DllImport("user32")]
            internal static extern bool GetMonitorInfo(IntPtr hMonitor, MONITORINFO lpmi);
    
            [DllImport("User32")]
            internal static extern IntPtr MonitorFromWindow(IntPtr handle, int flags);
    
            /// <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;
            };
    
            [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;
                }
            }
    
            [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;
            }
    
            #endregion
    
            #region add resize components
            private void connectMouseHandlers(UIElement element)
            {
                element.MouseLeftButtonDown += new MouseButtonEventHandler(element_MouseLeftButtonDown);
                element.MouseEnter += new MouseEventHandler(element_MouseEnter);
                element.MouseLeave += new MouseEventHandler(setArrowCursor);
            }
    
            public void addResizerRight(UIElement element)
            {
                connectMouseHandlers(element);
                rightElements.Add(element, 0);
            }
    
            public void addResizerLeft(UIElement element)
            {
                connectMouseHandlers(element);
                leftElements.Add(element, 0);
            }
    
            public void addResizerUp(UIElement element)
            {
                connectMouseHandlers(element);
                upElements.Add(element, 0);
            }
    
            public void addResizerDown(UIElement element)
            {
                connectMouseHandlers(element);
                downElements.Add(element, 0);
            }
    
            public void addResizerRightDown(UIElement element)
            {
                connectMouseHandlers(element);
                rightElements.Add(element, 0);
                downElements.Add(element, 0);
            }
    
            public void addResizerLeftDown(UIElement element)
            {
                connectMouseHandlers(element);
                leftElements.Add(element, 0);
                downElements.Add(element, 0);
            }
    
            public void addResizerRightUp(UIElement element)
            {
                connectMouseHandlers(element);
                rightElements.Add(element, 0);
                upElements.Add(element, 0);
            }
    
            public void addResizerLeftUp(UIElement element)
            {
                connectMouseHandlers(element);
                leftElements.Add(element, 0);
                upElements.Add(element, 0);
            }
            #endregion
    
            #region resize handlers
            private void element_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
            {
                GetCursorPos(out startMousePoint);
                startWindowSize = new Size(target.Width, target.Height);
                startWindowLeftUpPoint = new Point(target.Left, target.Top);
    
                #region updateResizeDirection
                UIElement sourceSender = (UIElement)sender;
                if (leftElements.ContainsKey(sourceSender))
                {
                    resizeLeft = true;
                }
                if (rightElements.ContainsKey(sourceSender))
                {
                    resizeRight = true;
                }
                if (upElements.ContainsKey(sourceSender))
                {
                    resizeUp = true;
                }
                if (downElements.ContainsKey(sourceSender))
                {
                    resizeDown = true;
                }
                #endregion
    
                Thread t = new Thread(new ThreadStart(updateSizeLoop));
                t.Name = "Mouse Position Poll Thread";
                t.Start();
            }
    
            private void updateSizeLoop()
            {
                try
                {
                    while (resizeDown || resizeLeft || resizeRight || resizeUp)
                    {
                        target.Dispatcher.Invoke(System.Windows.Threading.DispatcherPriority.Render, new RefreshDelegate(updateSize));
                        target.Dispatcher.Invoke(System.Windows.Threading.DispatcherPriority.Render, new RefreshDelegate(updateMouseDown));
                        Thread.Sleep(25);
                    }
    
                    target.Dispatcher.Invoke(System.Windows.Threading.DispatcherPriority.Render, new RefreshDelegate(setArrowCursor));
                }
                catch (Exception)
                {
                }
            }
    
            #region updates
            private void updateSize()
            {
                PointAPI currentMousePoint = new PointAPI();
                GetCursorPos(out currentMousePoint);
    
                try
                {
                    if (resizeRight)
                    {
                        //如果当鼠标左键点下时,窗口的宽度已经达到最小值,
                        if (target.Width == minWidth)
                        {
                            //鼠标向右移动,表示当前是将窗口变大,此时窗口只能变大,因为已经达到最小宽度了
                            if ((startMousePoint.X - currentMousePoint.X) < 0)
                            {
                                target.Width = this.startWindowSize.Width - (startMousePoint.X - currentMousePoint.X);
                            }
                        }
                        else
                        {
                            //此时,窗口可大可小
                            if ((this.startWindowSize.Width - (startMousePoint.X - currentMousePoint.X)) >= minWidth)
                            {
                                target.Width = this.startWindowSize.Width - (startMousePoint.X - currentMousePoint.X);
                            }
                            else
                            {
                                //此时,只能限制窗口为最小值,不能继续变小
                                target.Width = minWidth;
                            }
                        }
                    }
    
                    if (resizeDown)
                    {
                        if (target.Height == minHeight)
                        {
                            if ((startMousePoint.Y - currentMousePoint.Y) < 0)
                            {
                                //限制窗口的最底端，不能低于任务栏，即不能被任务栏遮挡
                                if (workAreaMaxHeight > 0)
                                {
                                    target.Height = (((startWindowSize.Height - (startMousePoint.Y - currentMousePoint.Y)) + target.Top) <= workAreaMaxHeight) ? (startWindowSize.Height - (startMousePoint.Y - currentMousePoint.Y)) : (workAreaMaxHeight - target.Top);
                                }
                                else
                                {
                                    target.Height = startWindowSize.Height - (startMousePoint.Y - currentMousePoint.Y);
                                }
                            }
                        }
                        else
                        {
                            if ((startWindowSize.Height - (startMousePoint.Y - currentMousePoint.Y)) >= minHeight)
                            {
                                if (workAreaMaxHeight > 0)
                                {
                                    target.Height = (((startWindowSize.Height - (startMousePoint.Y - currentMousePoint.Y)) + target.Top) <= workAreaMaxHeight) ? (startWindowSize.Height - (startMousePoint.Y - currentMousePoint.Y)) : (workAreaMaxHeight - target.Top);
                                }
                                else
                                {
                                    target.Height = startWindowSize.Height - (startMousePoint.Y - currentMousePoint.Y);
                                }
                            }
                            else
                            {
                                target.Height = minHeight;
                            }
                        }
                    }
    
                    if (resizeLeft)
                    {
                        if (target.Width == minWidth)
                        {
                            if ((startMousePoint.X - currentMousePoint.X) > 0)
                            {
                                target.Width = startWindowSize.Width + (startMousePoint.X - currentMousePoint.X);
                                target.Left = startWindowLeftUpPoint.X - (startMousePoint.X - currentMousePoint.X);
                            }
                        }
                        else
                        {
                            if ((this.startWindowSize.Width + (startMousePoint.X - currentMousePoint.X)) >= minWidth)
                            {
                                target.Width = startWindowSize.Width + (startMousePoint.X - currentMousePoint.X);
                                target.Left = startWindowLeftUpPoint.X - (startMousePoint.X - currentMousePoint.X);
                            }
                            else
                            {
                                target.Width = minWidth;
                                target.Left = startWindowLeftUpPoint.X + startWindowSize.Width - target.Width;
                            }
                        }
                    }
    
                    if (resizeUp)
                    {
                        if (target.Height == minHeight)
                        {
                            if ((startMousePoint.Y - currentMousePoint.Y) > 0)
                            {
                                target.Height = startWindowSize.Height + (startMousePoint.Y - currentMousePoint.Y);
                                target.Top = startWindowLeftUpPoint.Y - (startMousePoint.Y - currentMousePoint.Y);
                            }
                            else
                            {
                                target.Height = minHeight;
                                target.Top = startWindowLeftUpPoint.Y + startWindowSize.Height - target.Height;
                            }
                        }
                        else
                        {
                            if ((startWindowSize.Height + (startMousePoint.Y - currentMousePoint.Y)) >= minHeight)
                            {
                                target.Height = startWindowSize.Height + (startMousePoint.Y - currentMousePoint.Y);
                                target.Top = startWindowLeftUpPoint.Y - (startMousePoint.Y - currentMousePoint.Y);
                            }
                            else
                            {
                                target.Height = minHeight;
                                target.Top = startWindowLeftUpPoint.Y + startWindowSize.Height - target.Height;
                            }
                        }
                    }
                }
                catch
                {
                }
            }
    
            private void updateMouseDown()
            {
                if (Mouse.LeftButton == MouseButtonState.Released)
                {
                    resizeRight = false;
                    resizeLeft = false;
                    resizeUp = false;
                    resizeDown = false;
                }
            }
            #endregion
            #endregion
    
            #region cursor updates
            private void element_MouseEnter(object sender, MouseEventArgs e)
            {
                bool resizeRight = false;
                bool resizeLeft = false;
                bool resizeUp = false;
                bool resizeDown = false;
    
                UIElement sourceSender = (UIElement)sender;
                if (leftElements.ContainsKey(sourceSender))
                {
                    resizeLeft = true;
                }
                if (rightElements.ContainsKey(sourceSender))
                {
                    resizeRight = true;
                }
                if (upElements.ContainsKey(sourceSender))
                {
                    resizeUp = true;
                }
                if (downElements.ContainsKey(sourceSender))
                {
                    resizeDown = true;
                }
    
                if ((resizeLeft && resizeDown) || (resizeRight && resizeUp))
                {
                    setNESWCursor(sender, e);
                }
                else if ((resizeRight && resizeDown) || (resizeLeft && resizeUp))
                {
                    setNWSECursor(sender, e);
                }
                else if (resizeLeft || resizeRight)
                {
                    setWECursor(sender, e);
                }
                else if (resizeUp || resizeDown)
                {
                    setNSCursor(sender, e);
                }
            }
    
            private void setWECursor(object sender, MouseEventArgs e)
            {
                target.Cursor = Cursors.SizeWE;
            }
    
            private void setNSCursor(object sender, MouseEventArgs e)
            {
                target.Cursor = Cursors.SizeNS;
            }
    
            private void setNESWCursor(object sender, MouseEventArgs e)
            {
                target.Cursor = Cursors.SizeNESW;
            }
    
            private void setNWSECursor(object sender, MouseEventArgs e)
            {
                target.Cursor = Cursors.SizeNWSE;
            }
    
            private void setArrowCursor(object sender, MouseEventArgs e)
            {
                if (!resizeDown && !resizeLeft && !resizeRight && !resizeUp)
                {
                    target.Cursor = Cursors.Arrow;
                }
            }
    
            private void setArrowCursor()
            {
                target.Cursor = Cursors.Arrow;
            }
            #endregion
    
            #region external call
            [DllImport("user32.dll")]
            [return: MarshalAs(UnmanagedType.Bool)]
            static extern bool GetCursorPos(out PointAPI lpPoint);
    
            private struct PointAPI
            {
                public int X;
                public int Y;
            }
            #endregion
        }
    }

[WPF Window Resizing_CodeProject]: http://www.codeproject.com/Articles/23138/WPF-Window-Resizing
[Link 1]: http://download.csdn.net/detail/jiangxinyu/5120233