§ July 31, 2006

An IPAddress Control (the Win32 SysIPAddress32 control in C#)

The Common Controls library from the Platform SDK provides a control that Microsoft failed to provide a .NET counterpart to: the IPAddress Control (known as SysIPAddress32).

The TCP/IP Properties dialog


Quite a while ago I wrote a C# / .NET control that wrapped the functionality of the SysIPAddress32 control from comctl32.dll

My IPAddress Control Implementation

I had a much better implementation back then (with quite a few nice things included), but the hard drive that it lived on has since died, and I just haven't wanted to spend the time putting all that stuff back into the control.

Some time after having written the "nice" version of this control, I posted the following code to another website. Now, it's all I have left of the original. There is a known problem with the handle to the font being disposed incorrectly, but the code that fixed that, was given to me by jfo from Microsoft, and I did a cut/paste of the solution without really paying much attention to it (kind of regretting that now...). You may notice that all "system" fonts will always be displayed in BOLD in the forms designer (even when the font is set to something else). THIS GOES AWAY AT RUNTIME, so don't worry! It's only a problem in the designer.

Anyway, here it is, my IPAddress Control:

/******************************************************/
/*          NULLFX FREE SOFTWARE LICENSE              */
/******************************************************/
/*  IPAddressControl                                  */
/*  by: Steve Whitley                                 */
/*  © 2004 NullFX Software                            */
/*                                                    */
/* NULLFX SOFTWARE DISCLAIMS ALL WARRANTIES,          */
/* RESPONSIBILITIES, AND LIABILITIES ASSOCIATED WITH  */
/* USE OF THIS CODE IN ANY WAY, SHAPE, OR FORM        */
/* REGARDLESS HOW IMPLICIT, EXPLICIT, OR OBSCURE IT   */
/* IS. IF THERE IS ANYTHING QUESTIONABLE WITH REGARDS */
/* TO THIS SOFTWARE BREAKING AND YOU GAIN A LOSS OF   */
/* ANY NATURE, WE ARE NOT THE RESPONSIBLE PARTY. USE  */
/* OF THIS SOFTWARE CREATES ACCEPTANCE OF THESE TERMS */
/*                                                    */
/* USE OF THIS CODE MUST RETAIN ALL COPYRIGHT NOTICES */
/* AND LICENSES (MEANING THIS TEXT).                  */
/*                                                    */
/******************************************************/


namespace NullFX.Controls {
    using System;
    using System.Net;
    using System.Windows.Forms;
    using System.Runtime.InteropServices;
    using System.Diagnostics;
    using System.Drawing;
    [StructLayout(LayoutKind.Sequential)]
    public struct Nmhdr {
        public IntPtr HWndFrom;
        public UIntPtr IdFrom;
        public int Code;
    }
    [StructLayout(LayoutKind.Sequential)]
    public struct NmIPAddress {
        public Nmhdr Hdr;
        public int Field;
        public int Value;
    }
    [StructLayout(LayoutKind.Sequential)]
    public struct InitCommonControlsEX {
        public int Size;
        public int Icc;
    }
    public enum IPField { OctetOne = 0, OctetTwo = 1, OctetThree = 2, OctetFour = 3 }
    public delegate void FieldChangedHandler(object sender, FieldChangedEventArgs e);
    public class FieldChangedEventArgs : EventArgs {
        private int _field, _value;
        public int Field {
            get { return _field; }
        }
        public int Value {
            get { return _value; }
        }
        public FieldChangedEventArgs(int field, int value)
            : base() {
            _field = field;
            _value = value;
        }
    }
    public class IPAddressControl : TextBox {
        private const int WM_NOTIFY = 0x004E,
            WM_USER = 0x0400,
            WM_REFLECT = WM_USER + 0x1C00,
            IPN_FIRST = -860,
            IPM_SETRANGE = (WM_USER + 103),
            IPM_GETADDRESS = (WM_USER + 102),
            IPM_SETADDRESS = (WM_USER + 101),
            IPM_CLEARADDRESS = (WM_USER + 100),
            IPM_ISBLANK = (WM_USER + 105),
            ICC_INTERNET_CLASSES = 0x00000800,
            CS_VREDRAW = 0x0001,
            CS_HREDRAW = 0x0002,
            CS_DBLCLKS = 0x0008,
            CS_GLOBALCLASS = 0x4000,
            WS_CHILD = 0x40000000,
            WS_VISIBLE = 0x10000000,
            WS_TABSTOP = 0x00010000,
            WS_EX_RIGHT = 0x00001000,
            WS_EX_LEFT = 0x00000000,
            WS_EX_RTLREADING = 0x00002000,
            WS_EX_LTRREADING = 0x00000000,
            WS_EX_LEFTSCROLLBAR = 0x00004000,
            WS_EX_RIGHTSCROLLBAR = 0x00000000,
            WS_EX_NOPARENTNOTIFY = 0x00000004,
            WS_EX_CLIENTEDGE = 0x00000200;
        private int[] values = new int[4];
        bool initialized = false;		
        public event FieldChangedHandler FieldChanged;
        public IPAddressControl()
            : base() {
            for(int i = 0; i < 4; i++)
                values[i] = 0;
        }
        [DllImport("comctl32")]
        static extern bool InitCommonControlsEx(ref InitCommonControlsEX lpInitCtrls);

        protected virtual void OnFieldChanged(FieldChangedEventArgs e) {
            if(FieldChanged != null) FieldChanged(this, e);
        }
        protected override CreateParams CreateParams {
            get {
                if(!initialized) {
                    InitCommonControlsEX ic = new InitCommonControlsEX();
                    ic.Size = Marshal.SizeOf(typeof(InitCommonControlsEX));
                    ic.Icc = ICC_INTERNET_CLASSES;
                    initialized = InitCommonControlsEx(ref ic);
                }
                if(initialized) {
                    CreateParams cp = base.CreateParams;
                    cp.ClassName = "SysIPAddress32";
                    cp.Height = 23;
                    cp.ClassStyle = CS_VREDRAW | CS_HREDRAW | CS_DBLCLKS | CS_GLOBALCLASS;
                    cp.Style = WS_CHILD | WS_VISIBLE | WS_TABSTOP | 0x80;
                    cp.ExStyle = WS_EX_NOPARENTNOTIFY | WS_EX_CLIENTEDGE;
                    if(RightToLeft == RightToLeft.No 
                                                    || (RightToLeft == RightToLeft.Inherit 
                                                    && Parent.RightToLeft == RightToLeft.No)) {
                        cp.ExStyle |= WS_EX_LEFT | WS_EX_LTRREADING | WS_EX_RIGHTSCROLLBAR;
                    } else {
                        cp.ExStyle |= WS_EX_RIGHT | WS_EX_RTLREADING | WS_EX_LEFTSCROLLBAR;
                    }
                    return cp;
                } else {
                    return base.CreateParams;
                }
            }
        }
        public bool SetIPRange(IPField field, byte lowValue, byte highValue) {
            if(!initialized) return false;		
            Message m = Message.Create(Handle, IPM_SETRANGE, (IntPtr)((int)field), MakeRange(lowValue, highValue));
            WndProc(ref m);
            return m.Result.ToInt32() > 0;
        }
        public System.Net.IPAddress IPAddress {
            get {
                if(!initialized) return IPAddress.None;			
                return IPAddress.Parse(base.Text);
            }
        }
        public bool IsBlank {
            get {
                if(!initialized) return !(base.Text.Length > 0);
                Message m = Message.Create(Handle, IPM_ISBLANK, IntPtr.Zero, IntPtr.Zero);
                WndProc(ref m);
                return m.Result.ToInt32() > 0;
            }
        }
        new public void Clear() {
            if(!initialized) {
                base.Clear();
                return;
            }		
            Message m = Message.Create(Handle, IPM_CLEARADDRESS, IntPtr.Zero, IntPtr.Zero);
            WndProc(ref m);
        }
        private System.Net.IPAddress GetIpAddress(IntPtr ip) {
            if(!initialized) return IPAddress.None;		
            return new IPAddress(ip.ToInt64());
        }
        private IntPtr MakeRange(byte low, byte high) {
            return (IntPtr)((int)((high << 8) + low));
        }
        protected override void WndProc(ref Message m) {
            if(m.Msg == (WM_REFLECT + WM_NOTIFY)) {
                NmIPAddress ipInfo = (NmIPAddress)Marshal.PtrToStructure(m.LParam, typeof(NmIPAddress));
                if(ipInfo.Hdr.Code == IPN_FIRST) {
                    if(values[ipInfo.Field] != ipInfo.Value) {
                        values[ipInfo.Field] = ipInfo.Value;
                        OnFieldChanged(new FieldChangedEventArgs(ipInfo.Field, ipInfo.Value));
                    }
                }
            }
            base.WndProc(ref m);
        }
    }
}


It does have one wrapped event from the original control and that is FieldChanged, which provides feedback when each octet is changed (similar to TextChanged for a text box, but only fires after the user has entered the entire text for that octet). Likewise, if the value of that octet is larger than a byte, it is automatically changed back to 255 (or the max value of a byte). When the event fires, it passes back, the Octet that was changed, and its value.

You can specify the IP Range (which the original control allows, and I've wrapped into this control as well) so that you can edit the control to only accept a specified IP Address Range.

I've also provided Native Clear functionality as well as the IsBlank from the original control. I added a System.Net.IPAddress property so that when accessing the IPAddress of the control, you didn't need to parse the System.Net.IPAddress every time. My original control completely removed the "Text" property so that you got and set the IPAddress through this property, but alas, that functionality doesn't exist in this control.

UPDATE: 8/25/2006 - Made 2 changes to the source code. 1. added some Initialization logic to keep InitCommonCtrls from being called multiple times and, 2. added styles for ClassStyle, StyleEX and Style to keep an exception from being thrown in certain cases when a WM_GETTEXTLENGTH message was sent.

For questions, comments, bugs, or anything else in this control, feel free to use the Windows Controls section of the forum here.
Posted 11 years, 7 months ago on July 31, 2006

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