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 +1,136 @@
+using Ink_Canvas.Helpers;
+using System;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+
+namespace Ink_Canvas.Controls
+{
+    /// <summary>
+    /// 画布上的多页 PDF：仅显示当前页；翻页与页码由主窗口 PDF 侧栏控制（无 XAML 文件）。
+    /// </summary>
+    public class PdfEmbeddedView : UserControl
+    {
+        private readonly Image _pageImage;
+
+        private string _pdfPath;
+        private uint _pageCount;
+        private uint _currentIndex;
+        private bool _compressLargePictures;
+        private bool _isPagingBusy;
+        private bool _layoutSizeLocked;
+
+        /// <summary>页码或可翻页状态变化（用于更新侧栏）。</summary>
+        public event EventHandler PageNavigationStateChanged;
+
+        public PdfEmbeddedView()
+        {
+            MinWidth = 80;
+            MinHeight = 60;
+
+            var grid = new Grid { ClipToBounds = true };
+            _pageImage = new Image
+            {
+                Stretch = Stretch.Uniform,
+                HorizontalAlignment = HorizontalAlignment.Center,
+                VerticalAlignment = VerticalAlignment.Center
+            };
+            grid.Children.Add(_pageImage);
+            Content = grid;
+        }
+
+        /// <summary>
+        /// 初始化并显示第一页；由 MainWindow 在 UI 线程创建后调用。
+        /// </summary>
+        public async Task InitializeAsync(string pdfFilePath, uint pageCount, bool compressLargePictures)
+        {
+            _pdfPath = pdfFilePath ?? throw new ArgumentNullException(nameof(pdfFilePath));
+            _pageCount = pageCount;
+            _compressLargePictures = compressLargePictures;
+            _currentIndex = 0;
+
+            await ShowPageAsync(_currentIndex);
+        }
+
+        public string PdfPath => _pdfPath;
+
+        public uint PageCount => _pageCount;
+
+        public uint CurrentPageIndex => _currentIndex;
+
+        public string PageLabelText => _pageCount == 0 ? "" : $"{_currentIndex + 1} / {_pageCount}";
+
+        public bool CanGoPrevious => !_isPagingBusy && _pageCount > 1 && _currentIndex > 0;
+
+        public bool CanGoNext => !_isPagingBusy && _pageCount > 1 && _currentIndex < _pageCount - 1;
+
+        public async Task GoToPreviousPageAsync()
+        {
+            await GoRelativeAsync(-1);
+        }
+
+        public async Task GoToNextPageAsync()
+        {
+            await GoRelativeAsync(1);
+        }
+
+        private void NotifyPageNavigationStateChanged()
+        {
+            PageNavigationStateChanged?.Invoke(this, EventArgs.Empty);
+        }
+
+        private async Task GoRelativeAsync(int delta)
+        {
+            if (_isPagingBusy || _pageCount <= 1)
+                return;
+            int next = (int)_currentIndex + delta;
+            if (next < 0 || next >= _pageCount)
+                return;
+            _currentIndex = (uint)next;
+            await ShowPageAsync(_currentIndex);
+        }
+
+        private async Task ShowPageAsync(uint pageIndex)
+        {
+            _isPagingBusy = true;
+            NotifyPageNavigationStateChanged();
+            try
+            {
+                BitmapSource raw = await PdfWinRtHelper.RenderPageToBitmapSourceAsync(_pdfPath, pageIndex);
+                if (raw == null)
+                    return;
+
+                BitmapSource display = ApplyCompressionIfNeeded(raw);
+                _pageImage.Source = display;
+                if (!_layoutSizeLocked)
+                {
+                    Width = display.PixelWidth;
+                    Height = display.PixelHeight;
+                    _layoutSizeLocked = true;
+                }
+            }
+            finally
+            {
+                _isPagingBusy = false;
+                NotifyPageNavigationStateChanged();
+            }
+        }
+
+        private BitmapSource ApplyCompressionIfNeeded(BitmapSource rendered)
+        {
+            int width = rendered.PixelWidth;
+            int height = rendered.PixelHeight;
+            if (_compressLargePictures && (width > 1920 || height > 1080))
+            {
+                double scaleX = 1920.0 / width;
+                double scaleY = 1080.0 / height;
+                double scale = Math.Min(scaleX, scaleY);
+                return new TransformedBitmap(rendered, new ScaleTransform(scale, scale));
+            }
+
+            return rendered;
+        }
+    }
+}