Writing and Reading Pages

Take the following steps to start a project and to add some code that writes and reads pages to/from an image file:

  1. Start Visual Studio.
  2. Choose File->New->Project… from the menu.
  3. In the New Project dialog box, choose either "Visual C# Projects" or "VB Projects" in the Projects Type List, and choose "Windows Application " in the Templates List.
  4. Type the project name as " Writing and Reading Pages" in the Project Name field, and then click OK. If desired, type a new location for your project or select a directory using the Browse button, and then click OK .
  5. In the "Solution Explorer" window, right-click on the "References" folder, and select "Add Reference…" from the context menu. In the "Add Reference" dialog box, select the ".NET" tab and browse to Leadtools For .NET "<LEADTOOLS_INSTALLDIR>\Bin\DotNet4\Win32 " folder and select the following DLLs:

    • Leadtools.dll
    • Leadtools.Codecs.dll
    • Leadtools.Codecs.Tif.dll
    • Leadtools.Codecs.Fax.dll
    • Leadtools.Controls.WinForms.dll

    Press the Select button and then press the OK button to add the above DLLs to the application.

  6. Make sure Form1 is in design view. Go to the toolbox (View->Toolbox) and Drag and drop an instance of RasterImageViewer to the form. If you do not have RasterImageViewer in your toolbox, select Tools->Add Remove Toolbox Items from the menu. Click Browse and then select Leadtools.Controls.WinForms.DLL from "<LEADTOOLS_INSTALLDIR>\Bin\DotNet4\Win32" and then click Open and then click OK.

  7. From the toolbox (View->Toolbox ), add 4 Button controls as follows:

    Name Text
    Button1 First
    Button2 Previous
    Button3 Next
    Button4 Last
  8. Switch to Form1 code view (right-click Form1 in the solution explorer then select View Code ) and add the following lines at the beginning of the file:

    VB
    Imports Leadtools 
    Imports Leadtools.Codecs 
    Imports Leadtools.Controls.WinForms 
    C#
    using Leadtools; 
    using Leadtools.Codecs; 
    using Leadtools.Controls.WinForms; 

  9. Add an event handler to the Form1 Load event and add the following code:

    VB
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
       ' Intitialize a new RasterCodecs object. 
       Dim codecs As New RasterCodecs() 
       ' Load OCR1 to OCR4 and add them all to one image 
       Dim pageFileName() As String = _ 
       { _ 
          "C:\Users\Public\Documents\LEADTOOLS Images\Ocr1.tif", _ 
          "C:\Users\Public\Documents\LEADTOOLS Images\Ocr2.tif", _ 
          "C:\Users\Public\Documents\LEADTOOLS Images\Ocr3.tif", _ 
          "C:\Users\Public\Documents\LEADTOOLS Images\Ocr4.tif" _ 
       } 
       ' load all the files in pageFileName as pages into one image 
       Dim image As RasterImage = Nothing 
       For i As Integer = 0 To pageFileName.Length - 1 
          ' load the page image 
          Dim page As RasterImage = codecs.Load(pageFileName(i)) 
          If (i = 0) Then 
             ' first image, just save it into our variable 
             image = page 
          Else 
             ' add this page into our image 
             image.AddPage(page) 
             ' we do not need this page anymore 
             page.Dispose() 
          End If 
       Next 
       ' we can now use this image in our viewer. But let us try saving into a multi-page file then reloading it 
       Dim outputFileName As String = "C:\Users\Public\Documents\LEADTOOLS Images\Ocr_All.tif" 
       ' we can now just put "image" into the viewer, but lets save it as multi-page tiff and reload it 
       codecs.Save(image, outputFileName, RasterImageFormat.Tif, 1, 1, 4, 1, CodecsSavePageMode.Overwrite) 
       image.Dispose() 
       ' load this file into a new image and put in the viewer. 
       ' we know we have four pages, but let us use the GetInformation pages to get the number of pages 
       Dim info As CodecsImageInfo = codecs.GetInformation(outputFileName, True) 
       image = codecs.Load(outputFileName, 0, CodecsLoadByteOrder.BgrOrGray, 1, info.TotalPages) 
       ' set up the viewer into Fit mode 
       RasterImageViewer1.Zoom(ControlSizeMode.Fit, RasterImageViewer1.ScaleFactor, RasterImageViewer1.DefaultZoomOrigin) 
       ' view this image 
       RasterImageViewer1.Image = image 
       UpdateCaption() 
    End Sub 
                        
    Private Sub UpdateCaption() 
       Text = String.Format("Page {0} of {1}", RasterImageViewer1.Image.Page, RasterImageViewer1.Image.PageCount) 
    End Sub 
    C#
    private void Form1_Load(object sender, System.EventArgs e) 
    { 
       // Intitialize a new RasterCodecs object. 
       RasterCodecs codecs = new RasterCodecs(); 
       // Load OCR1 to OCR4 and add them all to one image 
       string[] pageFileName = 
       { 
          @"C:\Users\Public\Documents\LEADTOOLS Images\Ocr1.tif", 
          @"C:\Users\Public\Documents\LEADTOOLS Images\Ocr2.tif", 
          @"C:\Users\Public\Documents\LEADTOOLS Images\Ocr3.tif", 
          @"C:\Users\Public\Documents\LEADTOOLS Images\Ocr4.tif" 
       }; 
       // load all the files in pageFileName as pages into one image 
       RasterImage image = null; 
       for(int i = 0; i < pageFileName.Length; i++) 
       { 
          // load the page image 
          RasterImage page = codecs.Load(pageFileName[i]); 
          if(i == 0) 
          { 
             // first image, just save it into our variable 
             image = page; 
          } 
          else 
          { 
             // add this page into our image 
             image.AddPage(page); 
             // we do not need this page anymore 
             page.Dispose(); 
          } 
       } 
       // we can now use this image in our viewer. But let us try saving into a multi-page file then reloading it 
       string outputFileName = @"C:\Users\Public\Documents\LEADTOOLS Images\Ocr_All.tif"; 
       // we can now just put "image" into the viewer, but lets save it as multi-page tiff and reload it 
       codecs.Save(image, outputFileName, RasterImageFormat.Tif, 1, 1, 4, 1, CodecsSavePageMode.Overwrite); 
       image.Dispose(); 
       // load this file into a new image and put in the viewer. 
       // we know we have four pages, but let us use the GetInformation pages to get the number of pages 
       CodecsImageInfo info = codecs.GetInformation(outputFileName, true); 
       image = codecs.Load(outputFileName, 0, CodecsLoadByteOrder.BgrOrGray, 1, info.TotalPages); 
       // set up the viewer into Fit mode 
       rasterImageViewer1.Zoom(ControlSizeMode.Fit, RasterImageViewer1.ScaleFactor, RasterImageViewer1.DefaultZoomOrigin); 
       // view this image 
       rasterImageViewer1.Image = image; 
       UpdateCaption(); 
    } 
                        
    private void UpdateCaption() 
    { 
       Text = string.Format("Page {0} of {1}", rasterImageViewer1.Image.Page, rasterImageViewer1.Image.PageCount); 
    } 

  10. Double-click Button1 (First) on the form to add a handler for the Click event and add the following code:

    VB
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click 
       ' goto first page 
       If (RasterImageViewer1.Image.Page <> 1) Then 
          RasterImageViewer1.Image.Page = 1 
          UpdateCaption() 
       End If 
    End Sub 
    C#
    private void button1_Click(object sender, System.EventArgs e) 
    { 
       // goto first page 
       if(rasterImageViewer1.Image.Page != 1) 
       { 
          rasterImageViewer1.Image.Page = 1; 
          UpdateCaption(); 
       } 
    } 

  11. Double-click Button2 (Previous) on the form to add a handler for the Click event and add the following code:

    VB
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click 
       ' goto previous page 
       If (RasterImageViewer1.Image.Page > 1) Then 
          RasterImageViewer1.Image.Page = RasterImageViewer1.Image.Page - 1 
          UpdateCaption() 
       End If 
    End Sub 
    C#
    private void button2_Click(object sender, System.EventArgs e) 
    { 
       // goto previous page 
       if(rasterImageViewer1.Image.Page > 1) 
       { 
          rasterImageViewer1.Image.Page--; 
          UpdateCaption(); 
       } 
    } 

  12. Double-click Button3 (Next) on the form to add a handler for the Click event and add the following code:

    VB
    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click 
       ' goto next page 
       If (RasterImageViewer1.Image.Page < RasterImageViewer1.Image.PageCount) Then 
          RasterImageViewer1.Image.Page = RasterImageViewer1.Image.Page + 1 
          UpdateCaption() 
       End If 
    End Sub 
    C#
    private void button3_Click(object sender, System.EventArgs e) 
    { 
       // goto next page 
       if(rasterImageViewer1.Image.Page < rasterImageViewer1.Image.PageCount) 
       { 
          rasterImageViewer1.Image.Page++; 
          UpdateCaption(); 
       } 
    } 

  13. Double-click Button4 (Last) on the form to add a handler for the Click event and add the following code:

    VB
    Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click 
       ' goto last page 
       If (RasterImageViewer1.Image.Page <> RasterImageViewer1.Image.PageCount) Then 
          RasterImageViewer1.Image.Page = RasterImageViewer1.Image.PageCount 
          UpdateCaption() 
       End If 
    End Sub 
    C#
    private void button4_Click(object sender, System.EventArgs e) 
    { 
       // goto last page 
       if(rasterImageViewer1.Image.Page != rasterImageViewer1.Image.PageCount) 
       { 
          rasterImageViewer1.Image.Page = rasterImageViewer1.Image.PageCount; 
          UpdateCaption(); 
       } 
    } 

  14. Build, and Run the program to test it.
Help Version 20.0.2018.9.5
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