PDFOffice_Windows_exe/PDF Office/ViewModels/PropertyPanel/ViewModular/ReadModeContentViewModel.cs

using ComPDFKitViewer.PdfViewer;
using Dropbox.Api.Sharing;
using PDF_Office.Helper;
using PDF_Office.Model;
using Prism.Commands;
using Prism.Mvvm;
using Prism.Regions;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Windows.Controls;
using System.Windows.Forms;
using System.Windows.Input;
using static System.Windows.Forms.VisualStyles.VisualStyleElement.TrayNotify;
using System.Windows.Media;
using KeyEventArgs = System.Windows.Input.KeyEventArgs;
using TextBox = System.Windows.Controls.TextBox;
using static System.Windows.Forms.VisualStyles.VisualStyleElement;
using Button = System.Windows.Controls.Button;
using System.Windows.Controls.Primitives;

namespace PDF_Office.ViewModels.PropertyPanel.ViewModular
{
    public class ReadModeContentViewModel : BindableBase, INavigationAware
    {
        private ViewContentViewModel viewContentViewModel;
        private CPDFViewer PDFViewer;

        private int currentPage;

        public int CurrentPage
        {
            get { return currentPage; }
            set
            {
                SetProperty(ref currentPage, value);
            }
        }

        private int pageCount;

        public int PageCount
        {
            get { return pageCount; }
            set
            {
                SetProperty(ref pageCount, value);
            }
        }

        private bool CanNextPageExcute()
        {
            if (PDFViewer != null)
            {
                if (PDFViewer.CurrentIndex >= PDFViewer.Document.PageCount - 1)
                    return false;
                else
                    return true;
            }
            return false;
        }

        private bool CanPrePageExcute()
        {
            if (PDFViewer != null)
            {
                if (PDFViewer.CurrentIndex <= 0)
                    return false;
                else
                    return true;
            }
            return false;
        }

        private Button btnPrePage = null;
        private Button btnNextPage = null;
        private RepeatButton btnZoomOut = null;
        private RepeatButton btnZoomIn = null;

        public DelegateCommand<object> KeyDownCommand { get; set; }
        public DelegateCommand<object> PreviewKeyDownCommand { get; set; }
        public DelegateCommand<object> ZoomOutCommand { get; set; }
        public DelegateCommand<object> ZoomInCommand { get; set; }
        public DelegateCommand PrePageCommand { get; set; }
        public DelegateCommand NextPageCommand { get; set; }
        public DelegateCommand<object> LoadedCommand { get; set; }

        public ReadModeContentViewModel()
        {
            KeyDownCommand = new DelegateCommand<object>(KeyDownEvent);
            PreviewKeyDownCommand = new DelegateCommand<object>(PreviewKeyDownEvent);
            ZoomOutCommand = new DelegateCommand<object>(PageZoomOutEvent);
            ZoomInCommand = new DelegateCommand<object>(PageZoomInEvent);

            PrePageCommand = new DelegateCommand(PrePageEvent);
            NextPageCommand = new DelegateCommand(NextPageEvent);
            LoadedCommand = new DelegateCommand<object>(Loaded);
        }

        /// <summary>
        /// 页面加载
        /// </summary>
        /// <param name="obj"></param>
        private void Loaded(object obj)
        {
            if (obj is CompositeCommandParameter composite)
            {
                if (composite.Parameter is object[] array)
                {
                    btnPrePage = array[0] as Button;
                    btnNextPage = array[1] as Button;
                    btnZoomOut = array[2] as RepeatButton;
                    btnZoomIn = array[3] as RepeatButton;
                    ChangeBtnZoom();
                    ChangePageBtnState();
                }
            }
        }

        /// <summary>
        /// 下一页
        /// </summary>
        /// <param name="obj"></param>
        private void NextPageEvent()
        {
            if (PDFViewer.ModeView == ComPDFKitViewer.ViewMode.Double || PDFViewer.ModeView == ComPDFKitViewer.ViewMode.DoubleContinuous || PDFViewer.ModeView == ComPDFKitViewer.ViewMode.Book || PDFViewer.ModeView == ComPDFKitViewer.ViewMode.BookContinuous)

            {
                if (((int)PDFViewer.Mode % 2) == 0)
                {
                    PDFViewer.GoToPage(PDFViewer.CurrentIndex + 2);
                }
            }
            else
            {
                PDFViewer.GoToPage(PDFViewer.CurrentIndex + 1);
            }
        }

        /// <summary>
        /// 上一页
        /// </summary>
        /// <param name="obj"></param>
        private void PrePageEvent()
        {
            PDFViewer.GoToPage(PDFViewer.CurrentIndex - 1);
        }

        /// <summary>
        /// 放大
        /// </summary>
        /// <param name="obj"></param>
        private void PageZoomInEvent(object obj)
        {
            if (PDFViewer != null)
            {
                double zoom = SetPageZoomFactor(true);
                PDFViewer.Zoom(zoom / 100);
                ChangeBtnZoom();
            }
        }

        /// <summary>
        /// 设置缩放因子
        /// </summary>
        /// <param name="flag"></param>
        /// <returns></returns>
        private double SetPageZoomFactor(bool flag)
        {
            double zoom = PDFViewer.ZoomFactor * 100;
            if (flag)
            {
                if (zoom >= 25 && zoom <= 300)
                {
                    zoom = zoom + 25;
                }
                else if (zoom >= 301 && zoom <= 1000)
                {
                    zoom = zoom + 40;
                }
                else if (zoom >= 1001 && zoom <= 10000)
                {
                    zoom = zoom + 100;
                }
            }
            else
            {
                if (zoom >= 25 && zoom <= 300)
                {
                    zoom = zoom - 25;
                }
                else if (zoom >= 301 && zoom <= 1000)
                {
                    zoom = zoom - 40;
                }
                else if (zoom >= 1001 && zoom <= 10000)
                {
                    zoom = zoom - 100;
                }
            }

            if (zoom < 25)
            {
                zoom = 25;
            }
            if (zoom > 10000)
            {
                zoom = 10000;
            }
            return zoom;
        }

        /// <summary>
        /// 缩小
        /// </summary>
        /// <param name="obj"></param>
        private void PageZoomOutEvent(object obj)
        {
            if (PDFViewer != null)
            {
                double zoom = SetPageZoomFactor(false);
                PDFViewer.Zoom(zoom / 100);
                ChangeBtnZoom();
            }
        }

        /// <summary>
        /// 输入限制
        /// </summary>
        /// <param name="obj"></param>
        private void PreviewKeyDownEvent(object obj)
        {
            var args = obj as KeyEventArgs;
            if (args != null)
            {
                //显示文本框输入内容
                List<Key> NumberKeys = new List<Key>() { Key.D0, Key.D1, Key.D2, Key.D3, Key.D4, Key.D5, Key.D6, Key.D7, Key.D8, Key.D9, Key.NumPad0, Key.NumPad1, Key.NumPad2, Key.NumPad3, Key.NumPad4, Key.NumPad5, Key.NumPad6, Key.NumPad7, Key.NumPad8, Key.NumPad9, Key.Delete, Key.Back, Key.Enter, Key.Right, Key.Left };
                if (!NumberKeys.Contains(args.Key))
                {
                    args.Handled = true;
                }
            }
        }

        /// <summary>
        /// 回车键保存
        /// </summary>
        /// <param name="obj"></param>
        private void KeyDownEvent(object obj)
        {
            if (obj is CompositeCommandParameter objs)
            {
                if (objs.EventArgs is System.Windows.Input.KeyEventArgs keyEventArgs)
                {
                    TextBlock textBlock = objs.Parameter as TextBlock;
                    if (keyEventArgs.Key == Key.Enter)
                    {
                        if (keyEventArgs.OriginalSource is System.Windows.Controls.TextBox txtCurrentPageNum)
                        {
                            int pagenum = 0;
                            string text = txtCurrentPageNum.Text.ToString();
                            char[] chs = { ' ', '/', '\\' };//字符截取  拒止非法输入
                            int i = text.LastIndexOfAny(chs);
                            if (i > 0)
                            {
                                text = text.Substring(0, i - 1);
                            }
                            if (!int.TryParse(text, out pagenum))
                            {
                                CurrentPage = PDFViewer.Document.PageCount;
                                txtCurrentPageNum.Text = PDFViewer.Document.PageCount.ToString();
                                return;
                            }
                            if (pagenum < 1)
                            {
                                pagenum = 1;
                            }
                            else if (pagenum > PDFViewer.Document.PageCount)
                            {
                                pagenum = PDFViewer.Document.PageCount;
                            }

                            PDFViewer.GoToPage(pagenum - 1);
                            CurrentPage = pagenum;

                            textBlock.Visibility = System.Windows.Visibility.Visible;

                            txtCurrentPageNum.Text = pagenum.ToString();
                            txtCurrentPageNum.Background = new SolidColorBrush(Colors.Transparent);
                            //移动焦点
                            txtCurrentPageNum.MoveFocus(new TraversalRequest(FocusNavigationDirection.Next));
                        }
                    }
                }
            }
        }

        public bool IsNavigationTarget(NavigationContext navigationContext)
        {
            return true;
        }

        public void OnNavigatedFrom(NavigationContext navigationContext)
        {
        }

        public void OnNavigatedTo(NavigationContext navigationContext)
        {
            if (navigationContext.Parameters[ParameterNames.ViewContentViewModel] is ViewContentViewModel viewContentViewModel)
            {
                this.viewContentViewModel = viewContentViewModel;
            }
            if (navigationContext.Parameters[ParameterNames.PDFViewer] is CPDFViewer pdfview)
            {
                //获取页面设置等信息
                this.PDFViewer = pdfview;
                if (PDFViewer != null)
                {
                    PageCount = PDFViewer.Document.PageCount;
                    CurrentPage = PDFViewer.CurrentIndex + 1;
                    this.PDFViewer.InfoChanged += PDFViewer_InfoChanged;
                }
            }
        }

        /// <summary>
        /// 滚动的时候，参数变化
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void PDFViewer_InfoChanged(object sender, KeyValuePair<string, object> e)
        {
            if (e.Key == "SplieMode" || e.Key == "ViewMode")
            {
                return;
            }
            if (e.Key == "PageNum")
            {
                CurrentPage = (int)e.Value;
                PageCount = PDFViewer.Document.PageCount;
                ChangeBtnZoom();
                ChangePageBtnState();
            }
        }

        /// <summary>
        /// 改变缩放按钮
        /// </summary>
        private void ChangeBtnZoom()
        {
            if (PDFViewer == null)
            {
                return;
            }
            if (btnZoomOut == null && btnZoomIn == null)
            {
                return;
            }
            if (PDFViewer.ZoomFactor * 100 <= 25)
            {
                btnZoomOut.IsEnabled = false;
                btnZoomOut.Opacity = 0.5;

                btnZoomIn.IsEnabled = true;
                btnZoomIn.Opacity = 1;
            }
            else if (PDFViewer.ZoomFactor * 100 >= 25 && PDFViewer.ZoomFactor * 100 <= 10000)
            {
                btnZoomOut.Opacity = 1;
                btnZoomOut.IsEnabled = true;

                btnZoomIn.IsEnabled = true;
                btnZoomIn.Opacity = 1;
            }
            else
            {
                btnZoomIn.IsEnabled = false;
                btnZoomIn.Opacity = 0.5;

                btnZoomOut.IsEnabled = true;
                btnZoomOut.Opacity = 1;
            }
        }

        /// <summary>
        /// 改变上一页、下一页按钮
        /// </summary>
        private void ChangePageBtnState()
        {
            if (PDFViewer == null)
            {
                return;
            }
            if (btnPrePage == null && btnNextPage == null)
            {
                return;
            }
            if (PDFViewer.CurrentIndex + 1 <= 1)
            {
                btnPrePage.IsEnabled = false;
                btnPrePage.Opacity = 0.5;
            }
            else
            {
                btnPrePage.IsEnabled = true;
                btnPrePage.Opacity = 1;
            }
            if (PDFViewer.CurrentIndex + 1 >= PDFViewer.Document.PageCount)
            {
                btnNextPage.IsEnabled = false;
                btnNextPage.Opacity = 0.5;
            }
            else
            {
                btnNextPage.IsEnabled = true;
                btnNextPage.Opacity = 1;
            }
        }
    }
}