健保e化抽審-2(WIA：Scan to PDF)

上次是利用列印的方法轉換成數位化檔案(PDF)，這次則是使用掃瞄的方式來進行。利用WIA(Windows Image Acquisition)的掃瞄方式，可以將傳統的醫療單張掃瞄進來。

private void btnSacnToPDF_Click(object sender, EventArgs e)
{
 iTextSharp.text.Document document = new iTextSharp.text.Document(iTextSharp.text.PageSize.A4, 0, 0, 0, 0);
 try
 {
  List<string> devices = YGH.WIAScanner.GetDevices();
  if (devices.Count == 0)
  {
   throw new Exception("devices == 0");
  }

  List<System.Drawing.Image> images = YGH.WIAScanner.Scan(devices[0].Split('|')[0]);
  if (images.Count == 0)
  {
   throw new Exception("images == 0");
  }

  string fileName;
  // 方法1: 寫死暫存檔案名
  fileName = @"C:\temp\scan.pdf";
  // 方法2: 利用 System.IO.Path.GetTempPath() 及 Guid.NewGuid() 取得暫存檔案名
  //fileName = System.IO.Path.GetTempPath() + Guid.NewGuid().ToString() + ".pdf";
  // 方法3: 使用 System.IO.Path.GetTempFileName() 建立暫存檔案(副檔名為 .TMP)
  //fileName = System.IO.Path.GetTempFileName();

  PdfWriter.GetInstance(document, new FileStream(fileName, FileMode.Create));
  document.Open();

  foreach (System.Drawing.Image image in images)
  {
   iTextSharp.text.Image img = iTextSharp.text.Image.GetInstance(imageToByteArray(image));
   
   // 方法1: 跟 HP 內建掃瞄程式相比有明顯差異
   //img.ScaleToFit(document.PageSize.Width, document.PageSize.Height);

   // 方法2: 跟 HP 內建掃瞄程式相比差異較小
   img.SetAbsolutePosition(0, 0);
   img.ScalePercent(72.0F / img.DpiX * 100);

   // 方法3: 跟 HP 內建掃瞄程式相比有明顯差異
   //img.SetAbsolutePosition(0, 0);
   //img.ScaleAbsoluteWidth(document.PageSize.Width);
   //img.ScaleAbsoluteHeight(document.PageSize.Height);

   document.Add(img);
   document.NewPage();
  }
 }
 catch (Exception ex)
 {
  Console.WriteLine(ex.Message);
 }
 finally
 {
  document.Close();
 }
}

/// <summary>
/// C# Image to Byte Array and Byte Array to Image Converter Class
/// http://www.codeproject.com/Articles/15460/C-Image-to-Byte-Array-and-Byte-Array-to-Image-Conv
/// </summary>
/// <param name="imageIn"></param>
/// <returns></returns>
public byte[] imageToByteArray(System.Drawing.Image imageIn)
{
 MemoryStream ms = new MemoryStream();
 imageIn.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
 return ms.ToArray();
}

/// <summary>
/// C# Image to Byte Array and Byte Array to Image Converter Class
/// http://www.codeproject.com/Articles/15460/C-Image-to-Byte-Array-and-Byte-Array-to-Image-Conv
/// </summary>
/// <param name="byteArrayIn"></param>
/// <returns></returns>
public System.Drawing.Image byteArrayToImage(byte[] byteArrayIn)
{
 MemoryStream ms = new MemoryStream(byteArrayIn);
 System.Drawing.Image returnImage = System.Drawing.Image.FromStream(ms);
 return returnImage;
}

參考資料
[1] WIA Scanner in C# Windows Forms
[2] C# Image to Byte Array and Byte Array to Image Converter Class