PDFOffice_Windows_exe/PDF Office/ViewModels/Dialog/FullScreenWindowViewModel.cs

using ComPDFKitViewer.PdfViewer;
using PDF_Office.Model;
using Prism.Commands;
using Prism.Mvvm;
using Prism.Regions;
using Prism.Services.Dialogs;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;

namespace PDF_Office.ViewModels.Dialog
{
    public class FullScreenWindowViewModel : BindableBase, IDialogAware
    {
        public string Title => "";

        private Visibility showTip = Visibility.Collapsed;

        public Visibility ShowTip
        {
            get { return showTip; }
            set
            {
                SetProperty(ref showTip, value);
            }
        }

        private CPDFViewer PDFViewer;
        public DelegateCommand ExitCommand { get; set; }

        public DelegateCommand<object> LoadCommand { get; set; }

        public event Action<IDialogResult> RequestClose;

        public string RegionName { get; set; }

        /// <summary>
        /// 鼠标滚轮缩放的缩放值
        /// </summary>
        private double[] zoomLevel = { 1.00f, 10, 25, 50, 75, 100, 125, 150, 200, 300, 400, 600, 800, 1000 };

        public FullScreenWindowViewModel()
        {
            ExitCommand = new DelegateCommand(Exit);
            LoadCommand = new DelegateCommand<object>(Load);
            RegionName = Guid.NewGuid().ToString();
        }

        private void Exit()
        {
            RequestClose.Invoke(new DialogResult(ButtonResult.OK));
        }

        private void Load(object grid)
        {
            var Grid = grid as Grid;
            if(Grid!=null&&PDFViewer!=null)
            {
                    Grid.Children.Insert(0, PDFViewer);
                    ShowTip = Visibility.Visible;
            }
        }


        public bool CanCloseDialog()
        {
            return true;
        }

        public void OnDialogClosed()
        {
            if(PDFViewer!=null&&PDFViewer.Document!=null)
            {
                PDFViewer.Document.Release();
            }
        }

        public void OnDialogOpened(IDialogParameters parameters)
        {
            string filepath;
            string password;
            parameters.TryGetValue<string>(ParameterNames.FilePath,out filepath);
            parameters.TryGetValue<string>(ParameterNames.PassWord,out password);

            if (!string.IsNullOrEmpty(filepath))
            {
                PDFViewer = new CPDFViewer();
                PDFViewer.MouseWheelZoomHandler += PdfViewer_MouseWheelZoomHandler;
                PDFViewer.InitDocument(filepath);
                if (PDFViewer.Document == null)
                {
                    RequestClose?.Invoke(new DialogResult(ButtonResult.Cancel));
                }
                if (PDFViewer.Document.IsLocked && !string.IsNullOrEmpty(password))
                {
                    PDFViewer.Document.UnlockWithPassword(password);
                    if (PDFViewer.Document.IsLocked)
                    {
                        var dialogservice =  Prism.Ioc.ContainerLocator.Container.Resolve(typeof(IDialogService)) as IDialogService;
                        DialogParameters pairs = new DialogParameters();
                        pairs.Add(ParameterNames.PDFDocument,PDFViewer.Document);
                        dialogservice.ShowDialog(DialogNames.VerifyPassWordDialog,pairs,e=> { 
                            if(e.Result!=ButtonResult.OK)
                            {
                                RequestClose?.Invoke(new DialogResult(ButtonResult.Cancel));
                            }
                        });
                    }
                }
                PDFViewer.Load();
                PDFViewer.SetMouseMode(MouseModes.Default);
            }
        }


        #region PDFViewer缩放事件
        public void PdfViewer_MouseWheelZoomHandler(object sender, bool e)
        {
            double newZoom = CheckZoomLevel(PDFViewer.ZoomFactor + (e ? 0.01 : -0.01), e);
            PDFViewer.Zoom(newZoom);
        }

        private double CheckZoomLevel(double zoom, bool IsGrowth)
        {
            double standardZoom = 100;
            if (zoom <= 0.01)
            {
                return 0.01;
            }
            if (zoom >= 10)
            {
                return 10;
            }

            zoom *= 100;
            for (int i = 0; i < zoomLevel.Length - 1; i++)
            {
                if (zoom > zoomLevel[i] && zoom <= zoomLevel[i + 1] && IsGrowth)
                {
                    standardZoom = zoomLevel[i + 1];
                    break;
                }
                if (zoom >= zoomLevel[i] && zoom < zoomLevel[i + 1] && !IsGrowth)
                {
                    standardZoom = zoomLevel[i];
                    break;
                }
            }
            return standardZoom / 100;
        }
        #endregion
    }
}