.net - Windows Mobile Application for barcode scanning with Emulator -

i want develop simple application motorolo mc 9190 g mobile has inbuilt bar code scanner, want scan bar code , display them in msg box. dont have mobile have test in emulator. when deploy code in emulator gives null exception error. code add sample.barcode dll

private barcodereader symbol.barcode.reader // error occurs here  barcodereader = new symbol.barcode.reader() barcodereader.actions.enable() dim nextreaderdata symbol.barcode.readerdata = barcodereader.getnextreaderdata() messagebox.show(nextreaderdata.text) 

i mm beginner this.. pls help..

you need create interface , mock, along these lines:

interface ibarcodereader {     string readbarcode(); }  public class symbolreader : ibarcodereader {     private reader m_reader;      public symbolreader()     {         m_reader = new symbolreader.barcode.reader;         m_reader.actions.enable();     }      public string readbarcode()     {         return m_reader.getnextreaderdata().text;     } }  public class mockreader : ibarcodereader {     public string readbarcode()     {         return "mock abcde";     } } 

then @ runtime, use logic determine platform you're on , create appropriate instance:

public class foo {     ibarcodereader reader { get; set; }      public foo()     {         if (thisisasymboldevice)         {             reader = new symbolreader();         }         else         {             reader = new mockreader();         }          var barcode = reader.readbarcode();     } }