IP编辑控件（因为封装的是系统自带控件，所以也使用了CreateSubClass，不过为啥要封装CN_COMMAND和CN_NOTIFY不是很明白）

最近需要用一个IP输入控件，网上找了几个，都不符合效果，有些还有一些奇怪的Bug。后来发现原来系统已经提供了IP地址编辑控件，只是系统提供的控件不能设置只读效果。网上找了下资料，封装了一下，自己迂回一下实现了只读效果。

源码下载

unit ueIPEdit;
interface
uses
System.SysUtils, System.Classes, Vcl.Controls, Winapi.Windows, Winapi.Messages,
Vcl.ComCtrls, Winapi.CommCtrl;
type
TFieldChangeEvent = procedure(Sender: TObject; OldField, OldValue: Byte) of object;
TUeIPEdit = class(TWinControl)
private
FState: Integer; //Internal use
FBakIP: Longint; //Internal use
FMinIP: Longint;
FMaxIP: Longint;
FOnChange: TNotifyEvent;
FOnFieldChange: TFieldChangeEvent;
procedure CNNotify(var Message: TWMNotify); message CN_NOTIFY;
procedure CNCommand(var Message: TWMCommand); message CN_COMMAND;
protected
procedure CreateParams(var Params: TCreateParams); override;
function GetMinIP: String;
function GetMaxIP: String;
procedure SetMinIP(const Value: String);
procedure SetMaxIP(const Value: String);
procedure UpdateRange;
function GetIP: String;
procedure SetIP(const Value: String);
function GetEmpty: Boolean;
function GetReadOnly: Boolean;
procedure SetReadOnly(Value: Boolean);
function IPToString(const AIp: Longint): String;
function StringToIP(const Value: String): Longint;
public
constructor Create(AOwner: TComponent); override;
procedure Clear;
procedure SetActiveField(const Value: Integer);
property Empty: Boolean read GetEmpty;
property ReadOnly: Boolean read GetReadOnly write SetReadOnly;
property IP: String read GetIP write SetIP;
property MinIP: String read GetMinIP write SetMinIP;
property MaxIP: String read GetMaxIP write SetMaxIP;
property OnChange: TNotifyEvent read FOnChange write FOnChange;
property OnIPFieldChange: TFieldChangeEvent read FOnFieldChange write FOnFieldChange;
property Font;
property ParentColor;
property ParentFont;
property ParentShowHint;
property PopupMenu;
property ShowHint;
property TabOrder;
property TabStop;
property Tag;
property DragCursor;
property DragMode;
property HelpContext;
end;
implementation
uses Vcl.Graphics;
constructor TUeIPEdit.Create(AOwner: TComponent);
const
EditStyle = [csClickEvents, csSetCaption, csDoubleClicks, csFixedHeight, csPannable];
begin
inherited Create(AOwner);
if NewStyleControls then
ControlStyle := EditStyle else
ControlStyle := EditStyle + [csFramed];
ParentColor := False;
Color := clWindow;
Width:= 130;
Height:= 20;
TabStop:= True;
FState := 0;
FBakIP := -1;
FMinIP:= 0;
FMaxIP:= $0FFFFFFFF;
FOnChange:= nil;
FOnFieldChange:= nil;
end;
procedure TUeIPEdit.CreateParams(var Params: TCreateParams);
begin
InitCommonControl(ICC_INTERNET_CLASSES);
inherited CreateParams(Params);
CreateSubClass(Params, WC_IPADDRESS);
with Params do
begin
Style := WS_VISIBLE or WS_BORDER or WS_CHILD;
if NewStyleControls and Ctl3D then
begin
Style := Style and not WS_BORDER;
ExStyle := ExStyle or WS_EX_CLIENTEDGE;
end;
end;
end;
procedure TUeIPEdit.CNNotify(var Message: TWMNotify);
begin
if (FState=0) and Assigned(FOnFieldChange) and
(Message.NMHdr^.code=IPN_FIELDCHANGED) then
FOnFieldChange(Self, PNMIPAddress(Message.NMHdr)^.iField,
PNMIPAddress(Message.NMHdr)^.iValue);
end;
procedure TUeIPEdit.CNCommand(var Message: TWMCommand);
begin
if (Message.NotifyCode = EN_CHANGE) then
begin
case FState of
0: if Assigned(FOnChange) then FOnChange(Self);
1: begin
FState := 2;
PostMessage(Handle, IPM_SETADDRESS, 0, FBakIP);
end;
2: FState := 1;
end;
end;
end;
function TUeIPEdit.IPToString(const AIp: Longint): String;
begin
Result:= Format('%d.%d.%d.%d',[FIRST_IPADDRESS(AIp),SECOND_IPADDRESS(AIp),
THIRD_IPADDRESS(AIp),FOURTH_IPADDRESS(AIp)]);
end;
function TUeIPEdit.StringToIp(const Value: String): Longint;
var
B: array[0..3] of Byte;
Strs: TArray<string>;
i, Cnt : Integer;
begin
B[0]:= 0;
B[1]:= 0;
B[2]:= 0;
B[3]:= 0;
if Value<>'' then
begin
Strs := Value.Split(['.'],TStringSplitOptions.ExcludeEmpty);
try
Cnt := Length(Strs);
if Cnt>4 then Cnt := 4;
for i := 0 to Cnt-1 do
B[i] := StrToInt(Strs[i]);
finally
Strs := nil;
end;
end;
Result:= MakeIPAddress(b[0], b[1], b[2], b[3]);
end;
function TUeIPEdit.GetIP: String;
var
AIp: Longint;
begin
SendMessage(Handle, IPM_GETADDRESS, 0, Longint(@AIp));
Result:= IPToString(AIp);
end;
procedure TUeIPEdit.SetIP(const Value: String);
begin
SendMessage(Handle, IPM_SETADDRESS, 0, StringToIp(Value));
end;
function TUeIPEdit.GetMinIP: String;
begin
Result:= IPToString(FMinIP);
end;
procedure TUeIPEdit.SetMinIP(const Value: String);
var
AMin: LongInt;
begin
AMin := StringToIp(Value);
if FMinIP<>AMin then
begin
FMinIP := AMin;
UpdateRange;
end;
end;
procedure TUeIPEdit.UpdateRange;
begin
SendMessage(Handle, IPM_SETRANGE, 0, MAKEIPRANGE(FIRST_IPADDRESS(FMinIP), FIRST_IPADDRESS(FMaxIP)));
SendMessage(Handle, IPM_SETRANGE, 1, MAKEIPRANGE(SECOND_IPADDRESS(FMinIP), SECOND_IPADDRESS(FMaxIP)));
SendMessage(Handle, IPM_SETRANGE, 2, MAKEIPRANGE(THIRD_IPADDRESS(FMinIP), THIRD_IPADDRESS(FMaxIP)));
SendMessage(Handle, IPM_SETRANGE, 3, MAKEIPRANGE(FOURTH_IPADDRESS(FMinIP), FOURTH_IPADDRESS(FMaxIP)));
end;
procedure TUeIPEdit.SetMaxIP(const Value: String);
var
AMax: LongInt;
begin
AMax := StringToIp(Value);
if FMaxIP<>AMax then
begin
FMaxIP := AMax;
UpdateRange;
end;
end;
function TUeIPEdit.GetMaxIP: String;
begin
Result:= IPToString(FMaxIP);
end;
function TUeIPEdit.GetReadOnly: Boolean;
begin
Result := FState<>0;
end;
procedure TUeIPEdit.SetReadOnly(Value: Boolean);
begin
if Value <> GetReadOnly then
begin
if Value then
begin
SendMessage(Handle, IPM_GETADDRESS, 0, Longint(@FBakIP));
FState := 1;
end else begin
FState := 0;
end;
end;
end;
function TUeIPEdit.GetEmpty: Boolean;
begin
Result:= Boolean(SendMessage(Handle, IPM_ISBLANK, 0, 0));
end;
procedure TUeIPEdit.Clear;
begin
SendMessage(Handle, IPM_CLEARADDRESS, 0, 0);
end;
procedure TUeIPEdit.SetActiveField(const Value: Integer);
begin
if (Value < 4) then
begin
SendMessage(Handle, IPM_SETFOCUS, wParam(Value), 0);
end;
end;
end.

http://blog.csdn.net/tht2009/article/details/50623816