小知识,如Form淡出、捕捉Form最小化

(*)Form淡出
1)AnimateWindow(Form1.Handle,1000,AW_BLEND);//淡入
  AnimateWindow(Form1.Handle,1000,AW_HIDE or AW_BLEND);//淡出
2)窗体有AlphaBlend属性和AlphaBlendValue属性，将AlphaBlend属性设为True，然后在Timer组件中随着时间改变AlphaBlendValue的值（0-255）即可
  AlphaBlendValue:=1;//窗体透明

(*)捕捉Form最小化
定义一个过程
public
    PRocedure onminsize(var msg:twmsyscommand);message wm_syscommand;
procedure TForm1.onminsize(var msg: twmsyscommand);
begin
  if msg.CmdType=SC_MINIMIZE then
  begin
    form1.Width:=100;
    form1.Height:=100;
    form1.Left:=100;
    form1.Top:=300;
    exit;
  end;
  inherited;
end;

(*)createGuid(out newGUID)
   s:=GUIDToString(newGUID)

(*)四舍五入取正： y:=Round(x)

(*) string:=StringReplace(string1,'*','#',[rfReplaceAll]);

(*)把一个string用单引号括起来作为string返回
  QuotedStr(const S: string): string

(*) 如何让DBGRID中的内容分页显示
  ADODataSet1.Open;
  ADODataSet1.Recordset.PageSize := 10;           //显示第一页  
  ADODataSet1.Recordset.AbsolutePosition := 1;
  ADODataSet1.Recordset.PageSize := 10;           //显示第二页
  ADODataSet1.Recordset.AbsolutePosition := 11;

(*)实现解析ip地址为主机域名
uses WinSock
过程如下：
  function IPAddrToName(IPAddr : String): String;
  var
    SockAddrIn: TSockAddrIn;
    HostEnt: PHostEnt;
    WSAData: TWSAData;
  begin
    WSAStartup($101, WSAData);
    SockAddrIn.sin_addr.s_addr:= inet_addr(PChar(IPAddr));
    HostEnt:= gethostbyaddr(@SockAddrIn.sin_addr.S_addr, 4, AF_INET);
    if HostEnt<>nil then
    begin
      result:=StrPas(Hostent^.h_name)
    end
    else
    begin
      result:='';
    end;
  end;
使用函数：
var
  Name: string;
begin
  Name := InputBox('输入对方主机IP', '主机IP地址：', '');
  showmessage(IpAddrToName(Name));
end;

(*)去掉twebbrowser右边的ScrollBar
WebBrowser1.oleobject.Document.body.Scroll := 'no';

(*)TTreeView的结点如何具有CheckBox
TreeView有个Images属性，做三张小图片：
全选中、部分选中、不选状态（直接拍下CheckBox三种状态的图片在加工一下就可以了），然后在点击事件中根据具体情况设置TTreeNodes的ImageIndex就OK了。
重载TreeView的CreateParams：
type
  TCheckBoxTreeView = class(TTreeView)
  protected
    procedure CreateParams(var Params: TCreateParams); override;
  end;

procedure TCheckBoxTreeView.CreateParams(var Params: TCreateParams);
begin
  inherited;
  Params.Style:=Params.Style or TVS_CHECKBOXES;
  { TVS_CHECKBOXES declared in CommCtrl }
end;

如果要Check这个CheckBox，可以用下面的代码：
function IsNodeChecked(Node :TTreeNode) :Boolean;
const
  TVIS_CHECKED = $2000;
var
  TvItem :TTVItem;
begin
  TvItem.Mask  := TVIF_STATE;
  TvItem.hItem := Node.ItemId;
  TreeView_GetItem(Node.TreeView.Handle, TvItem);
  Result := (TvItem.State and TVIS_CHECKED) = TVIS_CHECKED;
end;

procedure SetNodeChecked(Node :TTreeNode; Checked :Boolean);
const
  TVIS_CHECKED = $2000;
var
  TvItem :TTVItem;
begin
  FillChar(TvItem, SizeOf(TvItem), 0);
  with TvItem do begin
    hItem     := Node.ItemId;
    Mask      := TVIF_STATE;
    StateMask := TVIS_STATEIMAGEMASK;
    if Checked then
      TvItem.State :=TVIS_CHECKED
    else
      TvItem.State :=TVIS_CHECKED shr 1;
    TreeView_SetItem(Node.TreeView.Handle, TvItem);
  end;
end;
可以做成事件和封装成一个类：
private OldState :Boolean;

procedure Change(Node: TTreeNode); override;
begin
  inherited Change(Node);
  OldState := IsNodeChecked(Node);
end;

procedure Click; override;
var
  NewState :Boolean;
begin
  inherited Click;
  NewState := IsNodeChecked(Self.Selected);
  if NewState = OldState then Exit;
  if (NewState) and Assigned(OnNodeChecked) then OnNodeChecked()
  else if (not NewState) and Assigned(OnNodeUnChecked) then
OnNodeUnChecked()

// OnNodeChecked & OnNodeUnchecked will be events that you declare
end;

(*)如何将stringgrid中每列的数据居中显示？
  (1)将stringgrid的defaultdraw设为：false;
  (2)procedure TForm1.StringGrid1DrawCell(Sender: TObject; ACol, ARow: Integer;  Rect: TRect; State: TGridDrawState);
var
  sText: string;
begin
  with StringGrid1 do
  begin
    sText := Cells[ACol, ARow];
    if sText <> '' then
    begin
      Canvas.FillRect(Rect);
      DrawText(Canvas.Handle, PChar(sText), Length(sText), Rect, DT_CENTER or DT_VCENTER or DT_SINGLELINE);
    end;
  end;
end;

DLL获得自己所在的路径:Windows.GetModuleFileName(HInstance,lp, 100);

Caption := Copy(Edit1.Text, 3, MaxInt); //建议，少计算一次

取得explorer句柄,线程
GetWindowThreadProcessID(FindWindow('ExploreWClass', nil), nil)
FindWindow('ExploreWClass', nil)

调用记事本
uses .... shellapi;
shellexecute(handle,nil,pchar('c:/windows/notepad'),nil,nil,sw_shownormal);

用回车代替TAB  在onkeypress  写
    if  key=#13 then perform(WM_NEXTDLGCTL,0,0);

fieldName like "%'+gA_FindValue+'%"'

formatFloat('0.00',doubleValue);  //格式化 Float ---> string

mailto:whj@aa.com?subject=subjectTille        ( &Attach=C:/Config.sys )

//返回给定月份的天数
uses SysUitls; // IsLeapYear
...
function DaysOfMonth(Date: TDateTime): integer;
var y, m, d: Word;
begin
   DecodeDate( Date, y, m, d );
   case m of
     2:  if IsLeapYear(y) then
           Result:=29 else Result:=28;
     1,3,5,7,8,10,12: Result:=31;
     4,6,9,11:        Result:=30;
  end;
end;

//触发一个错误
  raise Exception.Create('delete table Error');

//获取 IP 地址  (getIP.exe)
procedure TForm1.Button1Click(Sender: TObject);
var
  wVersionRequested : WORD;
  wsaData : TWSAData;
  p : PHostEnt;
  s : array[0..128] of char;
  p2 : pchar;
  OutPut:array[0..100] of char;
begin
 {Start up WinSock}
     wVersionRequested := MAKEWORD(1, 1);
     WSAStartup(wVersionRequested, wsaData);

{Get the computer name}
     GetHostName(@s, 128);
     p := GetHostByName(@s);

{Get the IpAddress}
     p2 := iNet_ntoa(PInAddr(p^.h_addr_list^)^);
     StrPCopy(OutPut,'Hostname: '+Format('%s', [p^.h_Name])+#10#13+
                       'IP address: '+Format('%s',[p2])
                       );
     WSACleanup;
     MessageBox(0,OutPut,'Get IP ! - this is your IP Address',mb_ok or mb_iconinformation);
end;