Question

I have created a service in Win7 using C#. Within that service I want to use the BlockInput function, which in Win7 it seems requires admin.

I set the serviceprocessorinstaller’s, account, username, and password to an admin account, within the code and the BlockInput doesn’t work. Note: under the service properties/logon tab it is set properly.

I then added a manifest for my service and set the requestedExecutionLevel to “requireAdministrator”. Yet the BlockInput still doesn’t want to work.

I tried moving the BlockInput down to the client level and then to a client wrapper but still it doesn’t want to work.

Running out of ideas…Any suggestions?

Start Edit Here:

Here is my manifest (or part of it, sorry formatting is terrible)
<assemblyIdentity version="1.0.0.0" name="BlockInputService.app"/>
<trustInfo xmlns="urn:schemas-microsoft-com:asm.v2">
<security>
<requestedPrivileges xmlns="urn:schemas-microsoft-com:asm.v3">
<requestedExecutionLevel level="requireAdministrator" uiAccess="false" />
</requestedPrivileges>
</security>
</trustInfo>

    namespace BlockInputService
    {
       [ServiceContract(Namespace = "http://BlockInputService")]
       public interface IBlockInputTest
       {
          [OperationContract]
          void BlockInputMethod();
       }

       public class BlockInputTest : IBlockInputTest
       {
          private const string SOURCE = "BlockInputService";
          private const string LOGNAME = "Application";

          [return: MarshalAs(UnmanagedType.Bool)]
          [DllImport("user32.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
          public static extern bool BlockInput([In, MarshalAs(UnmanagedType.Bool)] bool fBlockIt);

          public void BlockInputMethod()
          {
             if (!EventLog.SourceExists(SOURCE))
             {
                EventLog.CreateEventSource(SOURCE, LOGNAME);
             }

             try
             {
                bool flag = BlockInput(true);
                EventLog.WriteEntry(SOURCE, "BlockInput(true) returned: " + flag);

                EventLog.WriteEntry(SOURCE, "Sleep for 5 sec");
                Thread.Sleep(5000);
             }
             catch (Exception ex)
             {
                EventLog.WriteEntry(SOURCE, ex.Message);
             }
             finally
             {
                bool flag = BlockInput(false);
                EventLog.WriteEntry(SOURCE, "BlockInput(false) returned: " + flag);
             }
          }
       }
    }

Answer 1

I moved on and used SetWindowsHookEx to capture WH_KEYBOARD_LL and WH_MOUSE_LL events.

I tried everything I could think of to get the BlockInput to work. I still think I was just configuring my service wrong or something but I dont have time to worry about it anymore.

Thanks.