PDFOffice_Windows_exe/PDF Office/ViewModels/Tools/TextEditToolContentViewModel.cs

using Prism.Commands;
using Prism.Mvvm;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Media;
using System.Windows;
using PDF_Master.Model.PropertyPanel.AnnotPanel;
using System.Windows.Controls;
using Prism.Regions;
using ComPDFKitViewer.PdfViewer;
using PDF_Master.Model;
using Microsoft.Win32;
using PDF_Master.CustomControl;
using ComPDFKitViewer;
using System.Windows.Input;
using PDF_Master.Helper;
using ComPDFKitViewer.AnnotEvent;
using System.ComponentModel;
using System.IO;
using System.Drawing;
using System.Drawing.Imaging;
using PDF_Master.EventAggregators;
using Prism.Events;

namespace PDF_Master.ViewModels.Tools
{
    public class TextEditToolContentViewModel: BindableBase, INavigationAware
    {
        #region 属性与变量
        public ViewContentViewModel viewContentViewModel;
        private CPDFViewer PDFViewer;
        private IEventAggregator events;
        private IRegionManager regions;
        /// <summary>
        /// 用于区分事件的唯一码
        /// </summary>
        private string unicode;
        private Dictionary<string, string> btnToProperty = new Dictionary<string, string>();

        private bool _isTextEdit = false;
        public bool IsTextEdit
        {
            get { return _isTextEdit; }
            set { SetProperty(ref _isTextEdit, value);
            }
        }
        private bool _isImgEdit = false;
        public bool IsImgEdit
        {
            get { return _isImgEdit; }
            set
            {
                SetProperty(ref _isImgEdit, value);
            }
        }

        private bool _flg=false;
        public bool flg
        {
            get { return _flg; }
            set { SetProperty(ref _flg, value); }
        }

        /// <summary>
        /// 替换图片指令
        /// </summary>
        private bool _ReplaceImgflg = false;
        public bool ReplaceImgflg
        {
            get { return _ReplaceImgflg; }
            set { SetProperty(ref _ReplaceImgflg, value); }
        }

        /// <summary>
        /// 完成裁剪图片指令
        /// </summary>
        private bool _CropImgflg = false;
        public bool CropImgflg
        {
            get { return _CropImgflg; }
            set { SetProperty(ref _CropImgflg, value); }
        }
        /// <summary>
        /// 刷新预览图片指令
        /// </summary>
        private bool _REImgflg = false;
        public bool REImgflg
        {
            get { return _REImgflg; }
            set { SetProperty(ref _REImgflg, value); }
        }
        #endregion

        #region Command
        // 添加文本、图像
        public DelegateCommand<object> AddContentCommand { get; set; }
        public DelegateCommand AddTextCommand { get; set; }
        public DelegateCommand AddImgCommand { get; set; }
        public DelegateCommand EditTextModeCommand { get; set; }

        #endregion

        #region 初始化
        public TextEditToolContentViewModel(IRegionManager regionManager, IEventAggregator eventAggregator)
        {
            events = eventAggregator;
            unicode = App.mainWindowViewModel.SelectedItem.Unicode;
            regions = regionManager;
            InitCommand();
            InitBtnToProperty();
        }
        private void InitCommand()
        {
            AddContentCommand = new DelegateCommand<object>(AddContent);
            AddTextCommand = new DelegateCommand(AddText);
            AddImgCommand = new DelegateCommand(AddImg);
            EditTextModeCommand = new DelegateCommand(EditTextMode);
        }

        private void InitBtnToProperty()
        {
            btnToProperty.Add("Text", "TextEditProperty");
            btnToProperty.Add("Image", "ImageEditProperty");
            btnToProperty.Add("TextAndImage", "ImageTextEditProperty");
            btnToProperty.Add("PropertyPanelContent", "PropertyPanelContent");
        }

        #endregion
        #region 右键菜单

        //点击空白处时
        private ContextMenu EmptyStateMenu(object sender)
        {
            var popMenu = App.Current.FindResource("NoneMenu") as ContextMenu;
            CustomPopMenu customMenu = new CustomPopMenu(popMenu, sender);
            //粘贴
            customMenu.SetMenuBinding(0, ApplicationCommands.Paste);
            //添加文本
            customMenu.SetMenuBinding(1, AddTextCommand);
            //添加图像
            customMenu.SetMenuBinding(2, AddImgCommand);

            return popMenu;
        }

        //选中文字的框
        private ContextMenu SelectTextBorder(object sender)
        {
            var popMenu = App.Current.FindResource("SelectTextMenu") as ContextMenu;
            CustomPopMenu customMenu = new CustomPopMenu(popMenu, sender);
         
            //复制
            customMenu.SetMenuBinding(0, ApplicationCommands.Copy);
            //剪切
            customMenu.SetMenuBinding(1, ApplicationCommands.Cut);
            //粘贴
            customMenu.SetMenuBinding(2, ApplicationCommands.Paste);
            //删除
            customMenu.SetMenuBinding(3, ApplicationCommands.Delete);

            customMenu.SetVisibilityProperty(6, false);

            return popMenu;
        }
       
        //选中文字内容
        private ContextMenu SelectTextContent(object sender)
        {
            var popMenu = App.Current.FindResource("SelectContentMenu") as ContextMenu;
            CustomPopMenu customMenu = new CustomPopMenu(popMenu, sender);
            //复制
            customMenu.SetMenuBinding(0, ApplicationCommands.Copy);
            //剪切
            customMenu.SetMenuBinding(1, ApplicationCommands.Cut);
            //粘贴
            customMenu.SetMenuBinding(2, ApplicationCommands.Paste);
            //粘贴并匹配样式
            customMenu.SetVisibilityProperty(3, false);
            //删除
            customMenu.SetMenuBinding(4, ApplicationCommands.Delete);
            //全部选定
            customMenu.SetMenuBinding(5, ApplicationCommands.SelectAll);

            return popMenu;
        }

        //编辑中右键
        private ContextMenu EditTextContent(object sender)
        {
            var popMenu = App.Current.FindResource("NoneSelectContentMenu") as ContextMenu;
            CustomPopMenu customMenu = new CustomPopMenu(popMenu, sender);
            ////复制
            //customMenu.SetMenuBinding(0, ApplicationCommands.Copy);
            ////剪切
            //customMenu.SetMenuBinding(1, ApplicationCommands.Cut);
            //全部选定
            customMenu.SetMenuBinding(0, ApplicationCommands.SelectAll);
            //粘贴
            customMenu.SetMenuBinding(1, ApplicationCommands.Paste);
            //粘贴并匹配样式
            customMenu.SetVisibilityProperty(2, false);
            ////删除
            //customMenu.SetMenuBinding(4, ApplicationCommands.Delete);


            return popMenu;
        }
        #endregion
        #region 图片右键菜单

        //选中图像时
        private ContextMenu SelectImgPDFEdit(object sender)
        {
            var popMenu = App.Current.FindResource("SelectImgMenu") as ContextMenu;
            CustomPopMenu customMenu = new CustomPopMenu(popMenu, sender);
            //复制
            customMenu.SetMenuBinding(0, ApplicationCommands.Copy);
            //剪切
            customMenu.SetMenuBinding(1, ApplicationCommands.Cut);

            //粘贴
            customMenu.SetMenuBinding(2, ApplicationCommands.Paste);
            //删除
            customMenu.SetMenuBinding(3, ApplicationCommands.Delete);
            //裁剪
            customMenu.SetMenuBinding(4, new DelegateCommand(CropMode));
            //替换
            customMenu.SetMenuBinding(5, new DelegateCommand(ReplaceImg));
            //导出
            customMenu.SetMenuBinding(6, new DelegateCommand(ExportImg));
            return popMenu;
        }

        //选中裁剪图像时
        private ContextMenu CropImgPDFEdit(object sender)
        {
            var popMenu = App.Current.FindResource("CropImgMenu") as ContextMenu;
            CustomPopMenu customMenu = new CustomPopMenu(popMenu, sender);

            //确认裁剪
            customMenu.SetMenuBinding(0, new DelegateCommand(CropImg));
            //取消裁剪
            customMenu.SetMenuBinding(1, new DelegateCommand(CancelCropImg));
            //还原裁剪
            customMenu.SetMenuBinding(2, new DelegateCommand(RestoreCropImg));
            return popMenu;
        }
        //多选图片右键
        private ContextMenu SelectMoreImage(object sender)
        {
            var popMenu = App.Current.FindResource("SelectMoreImageMenu") as ContextMenu;
            CustomPopMenu customMenu = new CustomPopMenu(popMenu, sender);
            //复制
            customMenu.SetMenuBinding(0, ApplicationCommands.Copy);
            //剪切
            customMenu.SetMenuBinding(1, ApplicationCommands.Cut);
            //粘贴
            customMenu.SetMenuBinding(2, ApplicationCommands.Paste);
            //删除
            customMenu.SetMenuBinding(3, ApplicationCommands.Delete);
            //导出
            customMenu.SetMenuBinding(4, new DelegateCommand(ExportImg));


            return popMenu;
        }
        #endregion
        #region 快捷键
        private void ShortCut_KeyDown(object sender, KeyEventArgs e)
        {
            try
            {
                if (e.Key == Key.Escape)
                {
                    if (PDFViewer != null)
                    {
                        //缩小esc的操作范围
                        if (PDFViewer.ToolManager != null && PDFViewer.GetPDFEditCreateType() == ComPDFKit.PDFPage.CPDFEditType.EditText)
                        {
                            PDFViewer.RemovePDFEditEmptyText();
                            //只有在有画框的时候才进行
                            if (PDFViewer.MouseMode == MouseModes.PDFEdit&& PDFViewer.ToolManager.HasTool == true)
                            {
                                PDFViewer.RemoveTool(false);
                            }
                            else if (IsTextEdit == true || IsImgEdit == true)
                            {
                                IsImgEdit = false;
                                IsTextEdit = false;
                                PDFViewer.SetPDFEditCreateType(ComPDFKit.PDFPage.CPDFEditType.None);

                                //文本和图像都框选
                                PDFViewer.SetPDFEditType(ComPDFKit.PDFPage.CPDFEditType.EditText | ComPDFKit.PDFPage.CPDFEditType.EditImage);
                                PDFViewer.SetMouseMode(MouseModes.PDFEdit);                           
                                PDFViewer.ReloadDocument();
                                ShowPropertyPanel(false);
                            }
                        }

                        else if (PDFViewer.ToolManager != null && PDFViewer.GetPDFEditCreateType() == ComPDFKit.PDFPage.CPDFEditType.EditImage)
                        {

                            PDFViewer.RemovePDFEditEmptyText();
                            if (PDFViewer.MouseMode == MouseModes.PDFEdit&&PDFViewer.ToolManager.HasTool == true)
                            {
                                PDFViewer.RemoveTool(false);
                            }
                            else if (IsTextEdit == true || IsImgEdit == true)
                            {
                                IsImgEdit = false;
                                IsTextEdit = false;
                                PDFViewer.SetPDFEditCreateType(ComPDFKit.PDFPage.CPDFEditType.None);

                                //文本和图像都框选
                                PDFViewer.SetPDFEditType(ComPDFKit.PDFPage.CPDFEditType.EditText | ComPDFKit.PDFPage.CPDFEditType.EditImage);
                                PDFViewer.SetMouseMode(MouseModes.PDFEdit);      
                                PDFViewer.ReloadDocument();
                                ShowPropertyPanel(false);
                            }
                        }
                        




                    }
                }



            }
            catch
            {

            }
           
          

        }
        #endregion

        //模式选择进入
        public void AddContent(object obj)
        {
            if (PDFViewer == null || obj == null || obj as CustomIconToggleBtn == null) return;

            var btn = obj as CustomIconToggleBtn;
            EnterEditMode((bool)btn.IsChecked, btn.Tag.ToString());
        }
        //编辑按钮逻辑，暂时保留
        private void EditTextMode()
        {

        }
        
        //对应模式的逻辑
        private void EnterEditMode(bool isCheckMode,string modeType)
        {
            if (isCheckMode)
            {
                if (modeType == "Text")
                {
                    IsImgEdit = false;
                    IsTextEdit = true;

                    //只框选文本
                    PDFViewer.SetPDFEditType(ComPDFKit.PDFPage.CPDFEditType.EditText);

                    PDFViewer.SetMouseMode(MouseModes.PDFEdit);
                    PDFViewer.ReloadDocument();
                    PDFViewer.SetPDFEditCreateType(ComPDFKit.PDFPage.CPDFEditType.EditText);
                    AddToPropertyPanel("Text", null);
                    ShowPropertyPanel(true);
                }
                else
                {
                    IsImgEdit = true;
                    IsTextEdit = false;

                    //只框选图像
                    PDFViewer.SetPDFEditType(ComPDFKit.PDFPage.CPDFEditType.EditImage);

                    PDFViewer.SetPDFEditCreateType(ComPDFKit.PDFPage.CPDFEditType.EditImage);
                    PDFViewer.SetMouseMode(MouseModes.PDFEdit);
                    PDFViewer.ReloadDocument();
                    AddToPropertyPanel("PropertyPanelContent", null);
                    ShowPropertyPanel(true);

                }
            }
            else
            {
                IsImgEdit = false;
                IsTextEdit = false;
                PDFViewer.SetPDFEditCreateType(ComPDFKit.PDFPage.CPDFEditType.None);

                //文本和图像都框选
                PDFViewer.SetPDFEditType(ComPDFKit.PDFPage.CPDFEditType.EditText | ComPDFKit.PDFPage.CPDFEditType.EditImage);
                PDFViewer.SetMouseMode(MouseModes.PDFEdit);
                PDFViewer.ReloadDocument();
                ShowPropertyPanel(false);

            }
        }

        #region Command功能

        private void AddText()
        {
            EnterEditMode(true, "Text");
        }

        private void AddImg()
        {
            EnterEditMode(true, "Image");
        }
        //进入裁剪模式
        private void CropMode()
        {
            if (TextEditEvent != null)
            {
              
                TextEditEvent.ClipImage = true;
                TextEditEvent.UpdatePDFEditByEventArgs();
                flg = true;
            }
        }

        //取消裁剪
        private void CancelCropImg()
        {
            if (TextEditEvent != null)
            {
                TextEditEvent.ClipImage = false;
                TextEditEvent.CancelClip();
                flg = false;
                TextEditEvent.UpdatePDFEditByEventArgs();
            }
        }

        //还原裁剪
        private void RestoreCropImg()
        {
            if (TextEditEvent != null)
            {
                TextEditEvent.RestoreClip();
                events.GetEvent<PageEditNotifyEvent>().Publish(new PageEditNotifyEventArgs(unicode));
            }
            
        }

        //完成裁剪
        private void CropImg()
        {

            CropImgflg = true;
          
        }
        //导出图片
        private void ExportImg()
        {
            if (PDFViewer == null || TextEditEvent == null || TextEditEvent.EditType != ComPDFKit.PDFPage.CPDFEditType.EditImage) return;

            System.Windows.Forms.FolderBrowserDialog folder = new System.Windows.Forms.FolderBrowserDialog();
            folder.SelectedPath = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile);

            if (folder.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                if (string.IsNullOrEmpty(folder.SelectedPath))
                    return;

                var keyValueList = PDFViewer.GetSelectedImages();
                int i = 0;
                foreach (var bitmap in keyValueList)
                {
                    foreach (var bitmapItem in bitmap.Value)
                    {
                        bitmapItem.Save(folder.SelectedPath + "\\" + i + ".png", System.Drawing.Imaging.ImageFormat.Png);
                        i++;
                    }
                }

                var strFilePath = folder.SelectedPath + "\\0.png";
                CommonHelper.ShowFileBrowser(strFilePath);
            }
        }
            //替换图片
            private void ReplaceImg()
        {
            ReplaceImgflg = true;
        }

      
        //选中的图像
        private System.Windows.Media.Imaging.BitmapSource _currentImg;
        public System.Windows.Media.Imaging.BitmapSource CurrentImg { get { return _currentImg; } set { SetProperty(ref _currentImg, value); } }
        private void GetImagePreView()
        {
            try
            {
                var list = PDFViewer.GetSelectedImages();
                if (list != null && list.Count > 0)
                {
                    System.Drawing.Bitmap bitmap = null;
                    foreach (var item in list)
                    {
                        if (item.Value.Count > 0)
                        {
                            bitmap = item.Value[0];
                            break;
                        }
                    }

                    if (bitmap != null)
                    {
                        IntPtr ip = bitmap.GetHbitmap();
                        System.Windows.Media.Imaging.BitmapSource bitmapSource = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(ip, IntPtr.Zero, Int32Rect.Empty,
                        System.Windows.Media.Imaging.BitmapSizeOptions.FromEmptyOptions());
                        CurrentImg = bitmapSource;
                    }

                }
            }
            catch
            {

            }

        }
        #endregion



        //传参数给属性面板
        private void AddToPropertyPanel(string type,  List<PDFEditEvent> e)
        {
            if (btnToProperty.ContainsKey(type))
            {
                NavigationParameters parameters = new NavigationParameters();
                parameters.Add(ParameterNames.PDFViewer, PDFViewer);
                parameters.Add(ParameterNames.AnnotEvent, e);
                parameters.Add(ParameterNames.TextEditToolContentViewModel, this);
                System.Windows.Application.Current.Dispatcher.BeginInvoke(System.Windows.Threading.DispatcherPriority.Send, new Action(() =>
                {
                    regions.RequestNavigate(RegionNames.PropertyRegionName, btnToProperty[type], parameters);
                }));

                if(e!=null)
                {
                    ShowPropertyPanel(true);
                }
                else if(e==null&&IsImgEdit==false&&IsTextEdit==false)
                {
                    ShowPropertyPanel(false);
                }
            }
        }

        //控制属性面板是否展示
        private void ShowPropertyPanel(bool show = true)
        {
            viewContentViewModel.IsPropertyOpen = show;
        }

        private void OnViewModel1PropertyChanged(object sender, PropertyChangedEventArgs e)
        {
            if (e.PropertyName == "TabSelectedIndex")
            {
                if (viewContentViewModel.ToolTooRow == new GridLength(40))
                {
                    IsImgEdit = false;
                    IsTextEdit = false;
                    PDFViewer.SetPDFEditType(ComPDFKit.PDFPage.CPDFEditType.EditText | ComPDFKit.PDFPage.CPDFEditType.EditImage);
                    PDFViewer.SetMouseMode(MouseModes.PDFEdit);
                    PDFViewer.ReloadDocument();
                    PDFViewer.SetPDFEditCreateType(ComPDFKit.PDFPage.CPDFEditType.None);
                    AddToPropertyPanel("PropertyPanelContent", null);
                    ShowPropertyPanel(false);
                }
                else
                {

                    PDFViewer.SetPDFEditType(ComPDFKit.PDFPage.CPDFEditType.None);
                    PDFViewer.ReloadDocument();

                }
            }
        }
        public void OnNavigatedTo(NavigationContext navigationContext)
        {
            navigationContext.Parameters.TryGetValue<CPDFViewer>(ParameterNames.PDFViewer, out PDFViewer);
            navigationContext.Parameters.TryGetValue<ViewContentViewModel>(ParameterNames.ViewContentViewModel, out viewContentViewModel);

            if (PDFViewer != null)
            {
                viewContentViewModel.PropertyChanged += OnViewModel1PropertyChanged;
                //左键激活
                PDFViewer.PDFEditActiveHandler -= PDFViewer_PDFEditActiveHandler;
                PDFViewer.PDFEditActiveHandler += PDFViewer_PDFEditActiveHandler;

                //右键
                PDFViewer.PDFEditCommandHandler -= PDFViewer_PDFEditCommandHandler;
                PDFViewer.PDFEditCommandHandler += PDFViewer_PDFEditCommandHandler;


                //图片添加
                PDFViewer.CustomNotifyHandler -= PDFViewer_CustomNotifyHandler;
                PDFViewer.CustomNotifyHandler += PDFViewer_CustomNotifyHandler;

                //粘贴后选中
                PDFViewer.PDFEditHandler -= PDFViewer_PDFEditHandler;
                PDFViewer.PDFEditHandler += PDFViewer_PDFEditHandler;

                KeyEventsHelper.KeyDown -= ShortCut_KeyDown;
                KeyEventsHelper.KeyDown += ShortCut_KeyDown;
            }
        }

        private void PDFViewer_PDFEditHandler(object sender, List<PDFEditSelectionData> e)
        {
            PDFViewer.SelectPDFEdit(e,true);
        }

        protected PDFEditEvent TextEditEvent;
        //左键激活逻辑
        private void PDFViewer_PDFEditActiveHandler(object sender, List<PDFEditEvent> e)
        {

            if (e != null && e.Count > 0)
            {
                TextEditEvent=e[0];
                bool isText = false;
                bool isImg = false;
                foreach (var item in e)
                {

                    if (item.EditType == ComPDFKit.PDFPage.CPDFEditType.EditImage)
                    {
                        isImg = true;
                    }

                    if (item.EditType == ComPDFKit.PDFPage.CPDFEditType.EditText)
                    {
                        isText = true;
                    }

                }


                if (isText == true && isImg == false)
                {
                    AddToPropertyPanel("Text", e);
                  
                }
                if (isText == false && isImg == true)
                {
                    AddToPropertyPanel("Image", e);
                 
                }
                if (isText == true && isImg == true)
                {
                    AddToPropertyPanel("TextAndImage", e);
                   
                }
            }

            else if(IsTextEdit==true)
            {
                AddToPropertyPanel("PropertyPanelContent", null);
                AddToPropertyPanel("Text", null);
            }
            else
            {

                AddToPropertyPanel("PropertyPanelContent", null);
            }

            events.GetEvent<PageEditNotifyEvent>().Publish(new PageEditNotifyEventArgs(unicode));

        }

        //右键点击逻辑
        private void PDFViewer_PDFEditCommandHandler(object sender, PDFEditCommand e)
        {
            
            if (e == null)
                return;

            switch (e.CommandType)
            {
                case CommandType.Context:

                    if (e.EditType == ComPDFKit.PDFPage.CPDFEditType.None)//点击空白区域
                    {
                        e.PopupMenu = EmptyStateMenu(sender);

                    }
                    else if (e.EditType == ComPDFKit.PDFPage.CPDFEditType.EditText)
                    {

                         
                        //文字编辑
                        if (e.PressOnBorder == true)
                        {
                            e.PopupMenu = SelectTextBorder(sender);
                        }

                         else if(e.PressOnSelectedText == true)
                        {
                            e.PopupMenu = SelectTextContent(sender);
                        }

                        else if(e.SelectText=="")
                        {
                            e.PopupMenu= EditTextContent(sender);
                        }
                        else
                        {
                            e.PopupMenu = SelectTextContent(sender);
                        }

                    }
                   else if (e.EditType == ComPDFKit.PDFPage.CPDFEditType.EditImage)
                    {
                        if (e.IsClipState == true)
                        {
                            e.PopupMenu = CropImgPDFEdit(sender);
                        }
                        else
                        {
                            e.PopupMenu = SelectImgPDFEdit(sender);
                        }

                    }
                  
                        break;

                default:
                    e.DoCommand();
                    break;

            }
            if (e.PopupMenu != null)
            {
                e.Handle = true;
            }
            flg = e.IsClipState;
        }


        //图片添加逻辑
        private void PDFViewer_CustomNotifyHandler(object sender, CustomNotityData e)
        {

            if (e.NotifyType == CustomNotifyType.PDFEditImageCreate)
                {
                    OpenFileDialog openFileDialog = new OpenFileDialog();
                    openFileDialog.Filter = "Image Files(*.jpg;*.jpeg;*.png;*.bmp)|*.jpg;*.jpeg;*.png;*.bmp;";
                    if (openFileDialog.ShowDialog() == true)
                    {                 
                    PDFViewer.AddPDFEditImage(CompressImage(openFileDialog.FileName, 800), 500,500);
                    events.GetEvent<PageEditNotifyEvent>().Publish(new PageEditNotifyEventArgs(unicode));
                }
                }
            else if(e.NotifyType == CustomNotifyType.PDFEditImageResize)
            {
                REImgflg = true;
                events.GetEvent<PageEditNotifyEvent>().Publish(new PageEditNotifyEventArgs(unicode));
            }
        }

        /// <summary>
        /// 压缩
        /// </summary>
        /// <param name="filePath"></param>
        /// <param name="maxwidth"></param>
        /// <returns></returns>
        public static string CompressImage(string filePath, int maxwidth = 600)
        {
            try
            {
                string sourcepath = filePath;
                var guid = Guid.NewGuid().ToString();
                string folder = Path.Combine(App.CurrentPath, "Temp");
                if (!Directory.Exists(folder))
                {
                    Directory.CreateDirectory(folder);
                }
                var path = System.IO.Path.Combine(App.CurrentPath, "Temp", guid);

                Bitmap bitmap = new Bitmap(sourcepath);

                var b = bitmap;
                //bitmap.Dispose();

                double scale = Math.Min((double)maxwidth / b.Width, (double)maxwidth / b.Height);
                scale = Math.Min(scale, 1);
                System.Drawing.Size newsize = new System.Drawing.Size(maxwidth, maxwidth);
                newsize.Width = (int)(scale * b.Width);
                newsize.Height = (int)(scale * b.Height);

                if (!File.Exists(path))
                {
                    if (CheckTextFile(sourcepath) == FileExtension.PNG)
                    {
                        using (var bp = new Bitmap(b, (int)newsize.Width, (int)newsize.Height))
                        {
                            bp.Save(path, ImageFormat.Png);
                        }
                    }
                    else
                    {
                        using (var bp = new Bitmap(b, (int)newsize.Width, (int)newsize.Height))
                        {
                            bp.Save(path, ImageFormat.Jpeg);
                        }
                    }
                }
                return path;
            }
            catch
            {
                return filePath;
            }
        }


        /// <summary>
        ///  根据图片数据判断图片类型
        /// </summary>
        /// <param name="fileName"></param>
        /// <returns></returns>
        public static FileExtension CheckTextFile(string fileName)
        {
            FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read);
            System.IO.BinaryReader br = new System.IO.BinaryReader(fs);
            string fileType = string.Empty; ;
            try
            {
                byte data = br.ReadByte();
                fileType += data.ToString();
                data = br.ReadByte();
                fileType += data.ToString();
                FileExtension extension;
                try
                {
                    extension = (FileExtension)Enum.Parse(typeof(FileExtension), fileType);
                }
                catch
                {

                    extension = FileExtension.VALIDFILE;
                }
                return extension;
            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                if (fs != null)
                {
                    fs.Close();
                    br.Close();
                }
            }
        }

        public bool IsNavigationTarget(NavigationContext navigationContext)
        {
            return true;
        }
       
        public void OnNavigatedFrom(NavigationContext navigationContext)
        {
            IsImgEdit = false;
            IsTextEdit = false;
            PDFViewer.PDFEditActiveHandler -= PDFViewer_PDFEditActiveHandler;
            PDFViewer.PDFEditCommandHandler -= PDFViewer_PDFEditCommandHandler;
             PDFViewer.CustomNotifyHandler -= PDFViewer_CustomNotifyHandler;
            PDFViewer.PDFEditHandler -= PDFViewer_PDFEditHandler;
            KeyEventsHelper.KeyDown -= ShortCut_KeyDown;
            ShowPropertyPanel(false);
        }

    }
}