Help with coding

[markgoldin]

I am trying to get something like this working:

public class classA
{
// Here I want to do something with GetMessage form:
Form f = new getMessage.GetMessage();
f.Show();
does not work. Can that be actually done? Can I work with GetMesasge
form here?
}

public class classB
{

public class GetMessage : Form
{
public GetMessage()
{
Text = "my_unique_id";
}
}
}

Thanks

[Jon Skeet [C# MVP]]

markgoldin <ma*************@yahoo.comwrote:

I am trying to get something like this working:

public class classA
{
// Here I want to do something with GetMessage form:
Form f = new getMessage.GetMessage();
f.Show();
does not work. Can that be actually done? Can I work with GetMesasge
form here?
}

Well, there are a few problems here:

1) There's no such class as getMessage.GetMessage - there's
classB.GetMessage though

2) You're trying to write code directly into a class - aside from
variable initializers, code goes in methods (and properties etc).

If you change your code to:

public class classA
{
void SomeMethod()
{
// Here I want to do something with GetMessage form:
Form f = new classB.GetMessage();
f.Show();
}
}

then it will compile. Of course, you've then got to call SomeMethod...

--
Jon Skeet - <sk***@pobox.com>
Web site: http://www.pobox.com/~skeet
Blog: http://www.msmvps.com/jon.skeet
C# in Depth: http://csharpindepth.com

[Ignacio Machin ( .NET/ C# MVP )]

On Aug 20, 3:41*pm, "markgoldin" <[e-mail]:

I am trying to get something like this working:

public class classA
{
* * // Here I want to do something with GetMessage form:
* * Form f = new getMessage.GetMessage();
* * f.Show();
* * does not work. Can that be actually done? Can I work with GetMesasge
form here?

}

public class classB
{

* * public class GetMessage : Form
* * {
* * * * public GetMessage()
* * * * {
* * * * * * Text = "my_unique_id";
* * * * }
* * }

}

Thanks

what are you trying to do? not code, but in words

[markgoldin]

I am trying to adapt some code. Let me show it.
Some parts were removed from the sample.
//DataAdapterLauncher.cs
using System;
using System.Net.Sockets;
using Lightstreamer.DotNet.Server;
using System.Net;
using System.Threading;
using System.Windows.Forms;
using System.Runtime.InteropServices;
public class DataAdapterLauncher
{
static void Main(string[] args)
{
Form f = new SocketToLightStreamer.GetMessage();
f.Show();
f.Hide();
ApplicationContext ctx = new ApplicationContext();
Application.Run(ctx);
}
}

//SocketToLightStreamer.cs
using System.Collections;
using System.Threading;
using System;
using System.Runtime.InteropServices;
using Lightstreamer.Interfaces.Data;
using System.Windows.Forms;
public class SocketToLightStreamer : IDataProvider
{
private IItemEventListener _listener;
public void SetListener(IItemEventListener eventListener)
{
_listener = eventListener;
}
public class GetMessage : Form
{
const int WM_COPYDATA = 0x004a;
public GetMessage()
{
Text = "my_unique_id";
}
protected override void WndProc(ref System.Windows.Forms.Message m)
{
switch (m.Msg)
{
case WM_COPYDATA:
COPYDATASTRUCT mystr = new COPYDATASTRUCT();
Type mytype = mystr.GetType();
mystr = (COPYDATASTRUCT)m.GetLParam(mytype);
IDictionary eventData = new Hashtable();
eventData["scan"] = mystr.Data;
SocketToLightStreamer a = new SocketToLightStreamer();
a._listener.Update("floorupdate", eventData, false);
break;
}
base.WndProc(ref m);
}
}
[StructLayout(LayoutKind.Sequential)]
public struct COPYDATASTRUCT
{
public Int32 ID;
public int Length;
public string Data;
}
}
This code will compile fine, but when I run it I get "null reference" at a
line:
a._listener.Update("floorupdate", eventData, false);

[Peter Duniho]

On Wed, 20 Aug 2008 13:14:52 -0700, markgoldin <ma*************@yahoo.com>
wrote:

[...]
This code will compile fine, but when I run it I get "null reference"
at a
line:
a._listener.Update("floorupdate", eventData, false);

What reference is null? I'm presuming the member field "_listener" based
on the code you posted. It seems that the SetListener() method isn't ever
being called with a non-null reference. Do you have any reason to think
that it should have been?

Pete