WinForms中实现Adobe PDF Reader实现旋转PDF功能

实现效果：

问题点：Adobe PDF Reader中并没有可以直接旋转的方法

LoadFile	加载文件,文件URL地址
GotoFirstPage	到第一页
GotoLastPage	到最后一页
GotoPreviousPage	上一页
GotoNextPape	下一页
SetCurrentpage	到指定页
Setshowscrollbars	设置是否显示 Acrobat Reader的滚动条。带一个参数,该参数设为0时不显示滚动条,设为1时显示滚动条
SetshowToolbar	设置是否显示 Acrobat Reader的工具栏。带一个参数,该参数设为时不显示,设为1时显示。
Setview	设置显示效果。Fit：适应窗口大小； FitH：适合宽度
setZoom	设置文件的显示比例；默认是100

解决办法：引入PdfiumViewer旋转PDF并保存替换当前的文件。

		 /// <summary>
        /// 旋转保存PDF文件并释放文件锁定
        /// </summary>
        /// <param name="axControl"></param>
        /// <param name="filePath"></param>
        /// <param name="pdfRotation"></param>
        /// <returns></returns>
public bool SafeSavePdfWithRelease(AxAcroPDFLib.AxAcroPDF axControl, string filePath, PdfRotation pdfRotation)
    {
        const int MAX_RETRY = 3;
        const int RETRY_DELAY = 500;

        for (int attempt = 0; attempt < MAX_RETRY; attempt++)
        {
            try
            {
                // 步骤1：创建临时副本
                string tempPath = Path.GetTempFileName().Replace(".tmp", ".pdf");
                File.Copy(filePath, tempPath, true);

                // 步骤2：使用内存流操作
                using (var ms = new MemoryStream(File.ReadAllBytes(tempPath)))
                using (var document = PdfiumViewer.PdfDocument.Load(ms))
                {
                    for (int pageIndex = 0; pageIndex < document.PageCount; pageIndex++)
                    {
                        document.RotatePage(pageIndex, pdfRotation);

                        // 可选：验证旋转结果
                        // var currentRotation = document.Pages[pageIndex].Rotation;
                        // Debug.Assert(currentRotation == (int)rotation);
                    }
                    // 执行修改操作（示例：旋转第一页）
                    //document.RotatePage(1, PdfRotation.Rotate90);

                    // 步骤3：保存到临时文件
                    byte[] pdfBytes;
                    using (var outputStream = new MemoryStream())
                    {
                        document.Save(outputStream);
                        pdfBytes = outputStream.ToArray();
                    }

                    // 步骤4：强制释放文件锁定
                    ForceReleasePdfFile(axControl, filePath);

                    // 步骤5：原子替换文件
                    File.WriteAllBytes(tempPath, pdfBytes);
                    // File.Replace(tempPath, filePath, null, true);

                    // 1. 复制替换文件到目标路径
                    File.Copy(tempPath, filePath, overwrite: true);

                    // 2. 删除临时文件（可选）
                    File.Delete(tempPath);

                    // 步骤6：验证加载
                    axControl.LoadFile(filePath);
                    return true;
                }
            }
            catch (IOException ex) when (ex.HResult == -2147024864)
            {
                if (attempt == MAX_RETRY - 1) throw;
                Thread.Sleep(RETRY_DELAY);
            }
        }
        return false;
    }
    public void ForceReleasePdfFile(AxAcroPDFLib.AxAcroPDF axControl, string filePath)
    {
        // 步骤1：深度释放COM对象
        ReleaseComObject(axControl);

        // 步骤2：内核级文件解锁
        UnlockFileHandle(filePath);

        // 步骤3：延迟重载验证
        Thread.Sleep(200);
        axControl.LoadFile(filePath);
    }

    private void ReleaseComObject(AxAcroPDFLib.AxAcroPDF axControl)
    {
        try
        {
            // 显式释放ActiveX资源
            if (axControl.IsDisposed) return;

            // 反射调用内部释放方法
            var type = axControl.GetType();
            var method = type.GetMethod("ReleaseOCX", BindingFlags.Instance | BindingFlags.NonPublic);
            method?.Invoke(axControl, null);

            // 强制垃圾回收
            GC.Collect();
            GC.WaitForPendingFinalizers();
        }
        catch (Exception ex)
        {

        }
    }
    // 修改后的P/Invoke声明
    [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
    private static extern IntPtr CreateFile(
        string lpFileName,
        uint dwDesiredAccess,
        uint dwShareMode,
        IntPtr lpSecurityAttributes,
        FileMode dwCreationDisposition,  // 改用.NET枚举
        FileAttributes dwFlagsAndAttributes,  // 改用.NET枚举
        IntPtr hTemplateFile);

    // 修改后的UnlockFileHandle方法
    private void UnlockFileHandle(string filePath)
    {
        const uint FILE_SHARE_READ = 0x00000001;
        const uint FILE_SHARE_WRITE = 0x00000002;
        const uint GENERIC_READ = 0x80000000;

        IntPtr hFile = CreateFile(
            filePath,
            GENERIC_READ,
            FILE_SHARE_READ | FILE_SHARE_WRITE,
            IntPtr.Zero,
            FileMode.Open,  // 对应原生OPEN_EXISTING
            FileAttributes.Normal,  // 对应原生FILE_ATTRIBUTE_NORMAL
            IntPtr.Zero);

        if (hFile != IntPtr.Zero && hFile != new IntPtr(-1))
        {
            CloseHandle(hFile);
        }
    }

    [DllImport("kernel32.dll", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool CloseHandle(IntPtr hObject);`

调用代码：

		  /// <summary>
        /// 当前旋转角度
        /// </summary>
        public static int currentRotation = 0;

        /// <summary>
        /// 逆时针旋转
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void pictureEdit3_Click(object sender, EventArgs e)
        {
            if (axAcroPDF1.Visible)
            {
                currentRotation -= 90; 

                PdfRotation pdfRotation = GetCounterClockwiseRotation(currentRotation);

                var path = axAcroPDF1.src;
                //调用旋转PDF保存方法
                SafeSavePdfWithRelease(axAcroPDF1, path,pdfRotation);
                axAcroPDF1.LoadFile(path);
                axAcroPDF1.setView("Fit"); //适应窗口大小
            }
        }

        /// <summary>
        /// 顺时针旋转
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void pictureEdit2_Click(object sender, EventArgs e)
        {
            if (axAcroPDF1.Visible)
            {
                currentRotation += 90; 

                PdfRotation pdfRotation = GetCounterClockwiseRotation(currentRotation);

                var path = axAcroPDF1.src;
                //调用旋转PDF保存方法
                SafeSavePdfWithRelease(axAcroPDF1, path, pdfRotation);

                axAcroPDF1.LoadFile(path);
                axAcroPDF1.setView("Fit"); //适应窗口大小
            }
        }

        /// <summary>
        /// 通过旋转度数计算旋转的角度
        /// </summary>
        /// <param name="counterClockwiseDegrees">当前旋转角度</param>
        public static PdfRotation GetCounterClockwiseRotation(int counterClockwiseDegrees)
        {
            const int fullCircle = 360;
            int effectiveDegrees = counterClockwiseDegrees % fullCircle;

            if (effectiveDegrees < 0) effectiveDegrees += fullCircle; // 处理负角度

            if (currentRotation >= 360)
            {
                currentRotation = 0;
            }
            if (currentRotation <= -360)
            {
                currentRotation = 0;
            }

            switch (effectiveDegrees)
            {
                case 90:
                    return PdfRotation.Rotate90;
                case 180:
                    return PdfRotation.Rotate180;
                case 270:
                    return PdfRotation.Rotate270;
                case 0:
                default:
                    return PdfRotation.Rotate0;
            }
        }
        /// <summary>