c# - 如何像这个程序一样在 Windows 中覆盖最大 32x32 鼠标大小

Question

我希望我的程序能够覆盖 32x32 的最大鼠标尺寸，就像附图中的程序一样，图中的光标是 72x72。这是来自 ProcMon 的捕获，显示了光标更改时发生的情况。

但是，如果我尝试自己更改游标文件的注册表值，然后使用

推送更改

SystemParametersInfo(SPI.SPI_SETCURSORS, 0, IntPtr.Zero, SPIF.SPIF_SENDCHANGE);

然后光标会改变，但它仍然限制在 32x32 的最大尺寸。这个程序是如何绕过这个限制的？此外，光标在程序结束后仍然存在，因此它不能在运行时执行某些操作，但必须覆盖某处的设置。

谢谢你的帮助，我在网上找不到这样的东西，所以我什至不知道是否有人能得到答案。

编辑:我看到可以访问名为 C:\Windows\SysWOW64\Imageres.dll 的文件。它们只是读取，但也许这些游标存储在这里，或者它们以某种方式修改了这个文件。但我认为这可能会让比我更有经验的人走上正轨。

编辑 2:我相信大小是由 SM_CXCURSOR 和 SM_CYCURSOR 变量决定的。如果我能找到一种方法来设置这些，我可能会做生意。打算编写一个快速程序，通过运行程序和巨大的鼠标光标在 PC 上获取这些值，并查看它返回的内容...

编辑 3:运气不好；具有巨大光标的 PC 返回 32x32，因为它是 SM_CXCURSOR 和 SM_CYCURSOR。

Answer 1

使用 SetSystemCursor 可以将光标设置为比标准光标大得多的图像。

这是我用来调整系统游标大小的类:

using System;
using System.Drawing;
using System.Reflection;
using System.Runtime.InteropServices;

namespace WindowsFormsApplication1
{
    class SystemCursors
    {
        [DllImport("user32.dll")]
        static extern bool SetSystemCursor(IntPtr hcur, uint id);

        enum CursorShift
        {
            Centered,
            LowerRight,
        }

        public static void SetSystemCursorsSize(int newSize)
        {
            ResizeCursor(System.Windows.Forms.Cursors.AppStarting, newSize, CursorShift.LowerRight);
            ResizeCursor(System.Windows.Forms.Cursors.Arrow, newSize, CursorShift.LowerRight);
            ResizeCursor(System.Windows.Forms.Cursors.Cross, newSize, CursorShift.Centered);
            ResizeCursor(System.Windows.Forms.Cursors.Hand, newSize, CursorShift.LowerRight);
            ResizeCursor(System.Windows.Forms.Cursors.Help, newSize, CursorShift.LowerRight);
            ResizeCursor(System.Windows.Forms.Cursors.HSplit, newSize, CursorShift.Centered);
            ResizeCursor(System.Windows.Forms.Cursors.IBeam, newSize, CursorShift.Centered);
            ResizeCursor(System.Windows.Forms.Cursors.No, newSize, CursorShift.LowerRight);
            ResizeCursor(System.Windows.Forms.Cursors.NoMove2D, newSize, CursorShift.LowerRight);
            ResizeCursor(System.Windows.Forms.Cursors.NoMoveHoriz, newSize, CursorShift.LowerRight);
            ResizeCursor(System.Windows.Forms.Cursors.NoMoveVert, newSize, CursorShift.LowerRight);
            ResizeCursor(System.Windows.Forms.Cursors.PanEast, newSize, CursorShift.Centered);
            ResizeCursor(System.Windows.Forms.Cursors.PanNE, newSize, CursorShift.Centered);
            ResizeCursor(System.Windows.Forms.Cursors.PanNorth, newSize, CursorShift.Centered);
            ResizeCursor(System.Windows.Forms.Cursors.PanNW, newSize, CursorShift.Centered);
            ResizeCursor(System.Windows.Forms.Cursors.PanSE, newSize, CursorShift.Centered);
            ResizeCursor(System.Windows.Forms.Cursors.PanSouth, newSize, CursorShift.Centered);
            ResizeCursor(System.Windows.Forms.Cursors.PanSW, newSize, CursorShift.Centered);
            ResizeCursor(System.Windows.Forms.Cursors.PanWest, newSize, CursorShift.Centered);
            ResizeCursor(System.Windows.Forms.Cursors.SizeAll, newSize, CursorShift.Centered);
            ResizeCursor(System.Windows.Forms.Cursors.SizeNESW, newSize, CursorShift.Centered);
            ResizeCursor(System.Windows.Forms.Cursors.SizeNS, newSize, CursorShift.Centered);
            ResizeCursor(System.Windows.Forms.Cursors.SizeNWSE, newSize, CursorShift.Centered);
            ResizeCursor(System.Windows.Forms.Cursors.SizeWE, newSize, CursorShift.Centered);
            ResizeCursor(System.Windows.Forms.Cursors.UpArrow, newSize, CursorShift.Centered);
            ResizeCursor(System.Windows.Forms.Cursors.VSplit, newSize, CursorShift.Centered);
            ResizeCursor(System.Windows.Forms.Cursors.WaitCursor, newSize, CursorShift.LowerRight);
        }

        private static void ResizeCursor(System.Windows.Forms.Cursor cursor, 
            int newSize, CursorShift cursorShift)
        {
            Bitmap cursorImage = GetSystemCursorBitmap(cursor);
            cursorImage = ResizeCursorBitmap(cursorImage, new Size(newSize, newSize), cursorShift);
            SetCursor(cursorImage, getResourceId(cursor));
        }

        public static Bitmap GetSystemCursorBitmap(System.Windows.Forms.Cursor cursor)
        {
            Bitmap bitmap = new Bitmap(
                cursor.Size.Width, cursor.Size.Height,
                System.Drawing.Imaging.PixelFormat.Format32bppArgb);

            Graphics graphics = Graphics.FromImage(bitmap);

            cursor.Draw(graphics,
                new Rectangle(new Point(0, 0), cursor.Size));

            bitmap = Crop(bitmap);

            return bitmap;
        }

        private static Bitmap Crop(Bitmap bmp)
        {
            //code from http://stackoverflow.com/a/10392379/935052

            int w = bmp.Width;
            int h = bmp.Height;

            Func<int, bool> allWhiteRow = row =>
            {
                for (int i = 0; i < w; ++i)
                    if (bmp.GetPixel(i, row).A != 0)
                        return false;
                return true;
            };

            Func<int, bool> allWhiteColumn = col =>
            {
                for (int i = 0; i < h; ++i)
                    if (bmp.GetPixel(col, i).A != 0)
                        return false;
                return true;
            };

            int topmost = 0;
            for (int row = 0; row < h; ++row)
            {
                if (allWhiteRow(row))
                    topmost = row;
                else break;
            }

            int bottommost = 0;
            for (int row = h - 1; row >= 0; --row)
            {
                if (allWhiteRow(row))
                    bottommost = row;
                else break;
            }

            int leftmost = 0, rightmost = 0;
            for (int col = 0; col < w; ++col)
            {
                if (allWhiteColumn(col))
                    leftmost = col;
                else
                    break;
            }

            for (int col = w - 1; col >= 0; --col)
            {
                if (allWhiteColumn(col))
                    rightmost = col;
                else
                    break;
            }

            if (rightmost == 0) rightmost = w; // As reached left
            if (bottommost == 0) bottommost = h; // As reached top.

            int croppedWidth = rightmost - leftmost;
            int croppedHeight = bottommost - topmost;

            if (croppedWidth == 0) // No border on left or right
            {
                leftmost = 0;
                croppedWidth = w;
            }

            if (croppedHeight == 0) // No border on top or bottom
            {
                topmost = 0;
                croppedHeight = h;
            }

            try
            {
                var target = new Bitmap(croppedWidth, croppedHeight);
                using (Graphics g = Graphics.FromImage(target))
                {
                    g.DrawImage(bmp,
                      new RectangleF(0, 0, croppedWidth, croppedHeight),
                      new RectangleF(leftmost, topmost, croppedWidth, croppedHeight),
                      GraphicsUnit.Pixel);
                }
                return target;
            }
            catch (Exception ex)
            {
                throw new Exception(
                  string.Format("Values are topmost={0} btm={1} left={2} right={3} croppedWidth={4} croppedHeight={5}", topmost, bottommost, leftmost, rightmost, croppedWidth, croppedHeight),
                  ex);
            }
        }

        private static Bitmap ResizeCursorBitmap(Bitmap bitmap, Size size, CursorShift cursorShift)
        {
            if (size.Width > 32)
            {
                //shifting must occur
                Bitmap intermediateBitmap = new Bitmap(64, 64);
                Graphics intermediateGraphics = Graphics.FromImage(intermediateBitmap);
                if (cursorShift == CursorShift.LowerRight)
                    //place the mouse cursor in the lower right hand quadrant of the bitmap
                    intermediateGraphics.DrawImage(bitmap,
                        intermediateBitmap.Width / 2, intermediateBitmap.Height / 2);
                else if (cursorShift == CursorShift.Centered)
                    intermediateGraphics.DrawImage(bitmap,
                        intermediateBitmap.Width / 2 - bitmap.Width / 2,
                        intermediateBitmap.Height / 2 - bitmap.Height / 2);

                //now we have a shifted bitmap; use it to draw the resized cursor
                //Bitmap finalBitmap = new Bitmap(intermediateBitmap, size);    //normal quality
                Bitmap finalBitmap = new Bitmap(size.Width, size.Height);
                Graphics finalGraphics = Graphics.FromImage(finalBitmap);
                finalGraphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
                finalGraphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
                finalGraphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
                finalGraphics.DrawImage(intermediateBitmap, 0, 0, finalBitmap.Width, finalBitmap.Height);
                return finalBitmap;
            }
            else
            {
                Bitmap newBitmap = new Bitmap(bitmap, size);
                return newBitmap;
            }
        }

        private static uint getResourceId(System.Windows.Forms.Cursor cursor)
        {
            FieldInfo fi = typeof(System.Windows.Forms.Cursor).GetField(
                "resourceId", BindingFlags.NonPublic | BindingFlags.Instance);
            object obj = fi.GetValue(cursor);
            return Convert.ToUInt32((int)obj);
        }

        private static void SetCursor(Bitmap bitmap, uint whichCursor)
        {
            IntPtr ptr = bitmap.GetHicon();
            bool retval = SetSystemCursor(ptr, whichCursor);
        }

    }
}

它的工作原理是获取 System.Windows.Forms.Cursors 中提供的当前系统光标，并使用 Cursor.Draw 从中生成图像。然后将图像调整为所需的大小。这需要将光标图像移动到右下角(如箭头指针)或将光标图像置于较大图像的中心(如 Cross 和 IBeam)。

如果需要，您可以使用自己的图像作为光标，绕过所有调整大小的代码。只需将位图提供给 SetCursor。

一旦新的光标图像准备就绪，最后需要的数据就是我们要替换的光标的 ID。每个 System.Windows.Forms.Cursor 都包含此信息，但在私有(private)变量中，因此使用反射来获取值。如果您希望避免反射，则可以改为构建这些值的表。参见 MSDN SetSystemCursor获取值列表。

调用这个类就可以了

SystemCursors.SetSystemCursorsSize(128);