add:pdf插入

2026-04-05 17:31:35 +08:00
parent 1165e5bbf2
commit c77beb662e
9 changed files with 701 additions and 207 deletions
@@ -0,0 +1,80 @@
+using System;
+using System.IO;
+using System.Runtime.InteropServices.WindowsRuntime;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Media.Imaging;
+using Windows.Data.Pdf;
+using Windows.Storage;
+using Windows.Storage.Streams;
+
+namespace Ink_Canvas.Helpers
+{
+    /// <summary>
+    /// 使用 Windows.Data.Pdf（WinRT）将 PDF 页渲染为 WPF 可用的位图。
+    /// </summary>
+    internal static class PdfWinRtHelper
+    {
+        public static async Task<uint> GetPageCountAsync(string pdfPath)
+        {
+            if (string.IsNullOrWhiteSpace(pdfPath) || !File.Exists(pdfPath))
+                return 0;
+
+            var file = await StorageFile.GetFileFromPathAsync(pdfPath).AsTask();
+            var doc = await PdfDocument.LoadFromFileAsync(file).AsTask();
+            if (doc.IsPasswordProtected)
+                return 0;
+            return doc.PageCount;
+        }
+
+        public static async Task<BitmapSource> RenderPageToBitmapSourceAsync(string pdfPath, uint pageIndex)
+        {
+            if (string.IsNullOrWhiteSpace(pdfPath) || !File.Exists(pdfPath))
+                return null;
+
+            var file = await StorageFile.GetFileFromPathAsync(pdfPath).AsTask();
+            var doc = await PdfDocument.LoadFromFileAsync(file).AsTask();
+            if (doc.IsPasswordProtected)
+                return null;
+            if (pageIndex >= doc.PageCount)
+                return null;
+
+            var page = doc.GetPage(pageIndex);
+            try
+            {
+                using (var ras = new InMemoryRandomAccessStream())
+                {
+                    await page.RenderToStreamAsync(ras).AsTask();
+                    ras.Seek(0);
+
+                    var ms = new MemoryStream();
+                    using (var netStream = ras.AsStreamForRead())
+                        netStream.CopyTo(ms);
+                    ms.Position = 0;
+
+                    try
+                    {
+                        return await Application.Current.Dispatcher.InvokeAsync(() =>
+                        {
+                            var bi = new BitmapImage();
+                            bi.BeginInit();
+                            bi.StreamSource = ms;
+                            bi.CacheOption = BitmapCacheOption.OnLoad;
+                            bi.EndInit();
+                            bi.Freeze();
+                            return (BitmapSource)bi;
+                        });
+                    }
+                    finally
+                    {
+                        ms.Dispose();
+                    }
+                }
+            }
+            finally
+            {
+                (page as IDisposable)?.Dispose();
+            }
+        }
+    }
+}