delphi小技巧集锦

function GetKbStatus():string;
//返回当前键盘状态，包括NumLoce、Caps Lock、Insert
//每个状态信息占两个字符，顺序为:NumLoce、Caps Lock、Insert
//Copy Right 549@11:29 2003-7-22
var Status:string;
    KeyStates:TKeyboardState;
begin
  GetKeyboardState(KeyStates);
  if Odd(KeyStates[VK_NUMLOCK])then
    Status:='数字'
  else
    Status:='光标';
  if Odd(KeyStates[VK_CAPITAL]) then
    Status:=status+'大写'
  else
    Status:=status+'小写';
  if Odd(KeyStates[VK_INSERT]) then
    Status:=status+'插入'
  else
    Status:=status+'改写';
  Result:=Status;
end;

 

小技巧：
const ErrHead='操作出现错误，错误信息为：'+#13
  try
  ... 
  except
     on E: Exception do showmessage(ErrHead+E.Message+#13+'当前操作为：xxxxx');
  end;
可以让用户看到更多的错误信息，有助于客户反馈程序错误。

 

俺写得比较菜的，但是经常用的就是：

//>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
//执行Sql
//输入参数：SqlString, ADOQuery
//类型：    string,    TADOQuery
PRocedure TMainForm.ExeSql(SqlString: string; ADOQuery: TADOQuery);
begin
    with ADOQuery do
    begin
        Connection := DM.DBAccinfo;//这个是我的，可以添加用的connection
                                   //或者用use也可以。
        if Active then
            Active := False;
        Open;
        SQL.Clear;
        SQL.Add(SqlString);
        ExecSQL;
        Close;
    end;
end;

可能大家都知道这个。不过，我见过的代码里面，

好像很少人这么来写这么独立出来一个过程。

这个保证我自己原创……

//Open Adoquery
//根据reallike(爱翔(只有lizzy可以叫其他人不能)) 的过程改编
//支持多行sql
//可根据需要自己修改成只支持单行sql的过程，或者exesql过程
//Delphi6下测试通过。
procedure OpenSql(SqlString: tstrings; ADOQuery: TADOQuery);
var i:integer;
begin
  with ADOQuery do
    begin
      Close;
      SQL.Clear;
      for i:=0 to sqlstring.Count-1 do
      SQL.Add(SqlString[i]);
      try
        Open;
      except
        on e:exception do showmessage('错误：信息如下'+#13+e.Message);
      end;
  end;
end;
这个是单行sql的
procedure OpenSql1(SqlString: string; ADOQuery: TADOQuery);
begin
  with ADOQuery do
    begin
      Close;
      SQL.Clear;
      SQL.Add(SqlString);
      try
        Open;
      except
        on e:exception do showmessage('错误：信息如下'+#13+e.Message);
      end;
  end;
end;
嗬嗬，谢谢帮我修理这个东西。

不过你不使用Execsql吗？

我一般都在这个过程外面加try也就是引用他的地方。

也就是

Try
  Exesql(sqlstring, Adoquery1)
except
  //错误提示，乱七八糟的东西。
end
to: reallike(爱翔(只有lizzy可以叫其他人不能))
ExecSql的我也做了
//ExecSql Adoquery
//支持多行sql
//可根据需要自己修改成只支持单行sql的过程，或者exesql过程
//Delphi6下测试通过。
procedure ExeSql(SqlString: tstrings; ADOQuery: TADOQuery);
var i:integer;
begin
  with ADOQuery do begin
    Close;
    SQL.Clear;
    for i:=0 to sqlstring.Count-1 do
    SQL.Add(SqlString[i]);
    try
      ExecSql;
    except
      on e:exception do showmessage('错误：信息如下'+#13+e.Message);
    end;
  end;
end;
//我觉得except放在哪里都一样，放在外面好一点，因为，你可以添加一些其他的调试信息
//你说呢？
//有没有人把执行单行和执行多行的这两个过程合并成一个，那样就好了。
我也来两个，可以根据自己的需要进行增删，不过是针对DBGridEh的：

//动态建立Col
procedure BuildCol(vFieldName: string; vCaption: string; vWidth: Integer; var
  vGrid: TDBGridEh; iTag: Integer = 0;
  FooterType: TFooterValueType = fvtNon; FooterText: string = '';
  boolReadOnly: Boolean = True; vColor: TColor = clBtnFace);
var
  cCol: TDBGridColumnEh;
  cFooterCol: TColumnFooterEh;
begin
  cCol := TDBGridColumnEh.Create(vGrid.Columns);
  cCol.FieldName := vFieldName;
  cCol.Width := vWidth;
  cCol.Title.Caption := vCaption;
  cCol.Title.Alignment := taCenter;
  cCol.Title.Color := vColor;
  cCol.ReadOnly := boolReadOnly;
  //如果tag值为-1，则打印dbgrid时不打印该列
  cCol.Tag := iTag;

  if FooterType <> fvtNon then
  begin
    cFooterCol := cCol.Footers.Add;
    cFooterCol.ValueType := FooterType;
    if FooterType = fvtStaticText then
    begin
      vGrid.FooterRowCount := 1;
      cFooterCol.Value := FooterText;
    end;
    //cCol.Footer.FieldName:=;
  end;
end;

procedure TitleBtnClick(Sender: TObject; ACol: Integer;
  Column: TColumnEh; cdsHelper: TClientDataSetHelper);
var
  cdsTmp: TClientDataSet;
begin
  with (Sender as TDBGridEh) do
  begin
    cdsTmp := (DataSource.DataSet as TClientDataSet);
    if not cdsTmp.Active then Exit;
    //设置当前行的排序方式
    if Column.Title.SortMarker = smNoneEh then
    begin
      Column.Title.SortMarker := smUpEh;
      cdsHelper.SortByField(Column.FieldName, soAscending);
    end
    else
      if Column.Title.SortMarker = smUpEh then
      begin
        Column.Title.SortMarker := smDownEh;
        cdsHelper.SortByField(Column.FieldName, soDescending);
      end
      else
      begin
        Column.Title.SortMarker := smNoneEh;
        cdsHelper.SortByField(Column.FieldName, soNoSort);
      end;
  end;
end;

将DBGrid中各列的位置以及宽度记录入Ini文件，以及从Ini文件读取DBGrid中各列位置以及宽度的函数
procedure f_ReadIni(const Now_DBGrid:TDBGrid;Form_Name:String);
var
  FilePath:String;
  MyIniFile:Tinifile;
  Grid_Name,Field_Name:String;
  Width:integer;
  i,j,n:integer;
  Column:Array[0..100] of String;
  Widths:Array[0..100] of integer;
begin
  FilePath := ExtractFilePath(application.ExeName);
  MyIniFile:=TiniFile.Create(FilePath+'gsp.ini');
  Grid_Name :=Form_Name+','+Now_DBGrid.Name;
  n:= Now_DBGrid.Columns.Count-1 ;

  for i:=0 to 100 do column[i]:='';
  for i:=0 to n do
  begin
    Field_Name:=Now_DBGrid.Columns[i].FieldName;
    j:=MyIniFile.ReadInteger(Grid_Name,Field_Name,i);
    Column[j]:=Field_Name;
    Widths[j] :=MyIniFile.ReadInteger(Grid_Name,Field_Name+'_Width',Now_DBGrid.Columns[i].Width);
  end;

  for i:=0 to n do
  begin
    Now_DBGrid.Columns[i].FieldName := Column[i];
    Now_DBGrid.Columns[i].Width := Widths[i];
  end;

  MyIniFile.Destroy;
end;

procedure f_WriteIni(const Now_DBGrid:TDBGrid;Form_Name:String);
var
  FilePath:String;
  MyIniFile:Tinifile;
  Grid_Name,Field_Name:String;
  Width:Integer;
  i:integer;
begin
  FilePath := ExtractFilePath(Application.ExeName);
  MyIniFile:=TiniFile.Create(FilePath+'gsp.ini');
  Grid_Name :=Form_Name+','+Now_DBGrid.Name;

  for i:=0 to Now_DBGrid.Columns.Count-1 do
  begin
    Field_Name := Now_DBGrid.Columns[i].FieldName;
    Width := Now_DBGrid.Columns[i].Width;
    MyIniFile.WriteInteger(Grid_Name,Field_Name,i);
    MyIniFile.WriteInteger(Grid_Name,Field_Name+'_Width',Width);
  end;

  MyIniFile.Destroy;
end;

 

很久以前写得的，现在我都用类封装了。
unit MyFunc;

interface
uses
  Windows, SysUtils, MMSystem, WinSvc, Registry;

function CopyStrLeft(ch: Char; str: string): string;
function CopyStrRight(ch: Char; str: string): string;
function GetSelfPath: string;
procedure HideTask(bHide: Boolean);
function SoundCardInstalled: Boolean;
function GetHostip: String;
procedure DisableSvc(SvcName: string);
function GetRegisteredOwner: string;
function GetRegisteredOrganization: string;

implementation

function RegisterServiceProcess(dwProcessID, dwType: Integer): Integer; stdcall; external 'KERNEL32.DLL';

function CopyStrLeft(ch: Char; str: string): string;
begin
  Result:= Copy(str, 1, Pos(ch, str)-1)
end;

function CopyStrRight(ch: Char; str: string): string;
begin
  Result:= Copy(str, Pos(ch, str)+1, Length(str)-Pos(Ch, str)+1)
end;

function GetSelfPath: string;
begin
  Result:= ExtractFilePath(ParamStr(0))
end;

procedure HideTask(bHide: Boolean);
begin
  if bHide then RegisterServiceProcess(GetCurrentProcessID, 1)
           else RegisterServiceProcess(GetCurrentProcessID, 0);
end;

function SoundCardInstalled: Boolean;
begin
  Result:= WaveOutGetNumDevs >0
end;

function GetHostIP: String;
type
  TaPInAddr = Array[0..10] of PInAddr;
  PaPInAddr = ^TaPInAddr;
var
  phe: PHostEnt;
  PPTr: PaPInAddr;
  Buffer: Array[0..63] of Char;
  I: Integer;
  GInitData: TWSAData;
begin
  WSAStartup($101,GInitData);
  GetHostName(Buffer,SizeOf(Buffer));
  phe:= GetHostByName(buffer);
  if phe = nil then Exit;
  pPtr:= PaPInAddr(phe^.h_addr_list);
  I:= 0;
  Result:=inet_ntoa(pptr^[I]^);
  WSACleanup;
end;

procedure DisableSvc(SvcName: string);
var
   scMngr: THandle;
   scSvc: THandle;
begin
  scMngr:= OpenSCManager(nil, nil, sc_Manager_all_access);
  scSvc:= OpenService(scMngr, SvcName, SERVICE_CHANGE_CONFIG);
  ChangeServiceConfig(scSvc,
    SERVICE_NO_CHANGE,
    SERVICE_DISABLED,
    SERVICE_NO_CHANGE,
    nil,nil,nil,nil,nil,nil,nil);
  CloseServiceHandle(scSvc);
end;

function GetRegisteredOwner: string;
var
  OSVersion: TOSVersionInfo;
  sWinKey: string;
begin
  OSVersion.dwOSVersionInfoSize := SizeOf(OSVersion);
  GetVersionEx(OSVersion);
  case OSVersion.dwPlatformID of
    VER_PLATFORM_WIN32_WINDOWS: sWinKey := '/SOFTWARE/Microsoft/Windows/CurrentVersion';
    VER_PLATFORM_WIN32_NT:      sWinKey := '/SOFTWARE/Microsoft/Windows NT/CurrentVersion';
  end;
  with TRegistry.Create do
  try
    RootKey := HKEY_LOCAL_MACHINE;
    OpenKey(sWinKey, False);
    Result := ReadString('RegisteredOwner');
  finally
     Free;
  end;
end;

function GetRegisteredOrganization: string;
var
  OSVersion: TOSVersionInfo;
  sWinKey: string;
begin
  OSVersion.dwOSVersionInfoSize := SizeOf(OSVersion);
  GetVersionEx(OSVersion);
  case OSVersion.dwPlatformID of
    VER_PLATFORM_WIN32_WINDOWS: sWinKey := '/SOFTWARE/Microsoft/Windows/CurrentVersion';
    VER_PLATFORM_WIN32_NT:      sWinKey := '/SOFTWARE/Microsoft/Windows NT/CurrentVersion';
  end;
  with TRegistry.Create do
  try
    RootKey := HKEY_LOCAL_MACHINE;
    OpenKey(sWinKey, False);
    Result := ReadString('RegisteredOrganization');
  finally
     Free;
  end;
end;

end.

先放几个

//删除某目录下所有指定扩展名文件
function DelFile(sDir,fExt: string): Boolean;
var
   hFindFile: HWND;
   FindFileData: WIN32_FIND_DATA;
   sr: TSearchRec;
begin
  sDir:= sDir + '/';
  hFindFile:= FindFirstFile(pchar(sDir + fExt), FindFileData);
  if hFindFile <> NULL then
    begin
      deletefile(sDir + FindFileData.cFileName);
      while FindNextFile(hFindFile, FindFileData) <> FALSE do
        deletefile(sDir + FindFileData.cFileName);
    end;
  sr.FindHandle:= hFindFile;
  FindClose(sr);
end;

//延时
procedure mDelay(MSecs: DWord);
var
  BeginTime: DWORD;
begin
  BeginTime := GetTickCount;
  repeat
    Application.ProcessMessages;
  until GetTickCount - BeginTime >= MSecs;
end;

//格式化浮点型
function my_FormatFloat(r: Real; u: Integer): Real;
var
  vStr : String;
  I : Integer;
begin
  if u <= 0 then
    Result := r
  else
    begin
      vStr := '0';
      for I := 1 to u - 1 do
        vStr := vStr + '0';
      vStr := '0.' + vStr;
      Result := StrToFloat(FormatFloat(vStr, r));
    end;
end;

//得到某字符串中指定位置的子串
//如get_substr('aa##bb##cc##dd','##',3)返回'cc'
function get_substr(s_str,d_str:string;po:integer):string; //s_str大字符串，d_str分隔符,po位置
var
  i,j,k:integer;
begin
  result:='';
  if po<1 then
    exit;
  s_str:=trim(s_str)+d_str;
  i:=0;
  while 1=1 do
    begin
      if pos(d_str,s_str)>0 then
        begin
          j:=pos(d_str,s_str)+length(d_str);
          k:=length(s_str)-(j-1);
          i:=i+1;
          if i=po then
            begin
              j:=pos(d_str,s_str);
              result:=copy(s_str,1,j-1);
              break;
            end;
          s_str:=copy(s_str,j,k);
        end
      else
        break;
    end;
end;

//得到当前日期的月首日和月末日
function get_date(da:TDateTime;zt:integer):TDateTime;
var
  yy,mm,dd:string;
begin
  yy:=formatdatetime('yyyy',da);
  mm:=formatdatetime('mm',da);
  if zt=0 then
    dd:='01'
  else
    begin
      if strtoint(mm) in [1,3,5,7,8,10,12] then
        dd := '31'
      else
        if mm <> '2' then
          dd:='30'
        else
          if IsLeapYear(YearOf(Da)) then
            dd:='29'
          else
            dd:='28';
    end;
  DateSeparator := '-';
  result:=strtodate(yy + '-' + mm +'-' + dd);
end;

//表的存在与否
function IsExist(tb:String;query:TADOQuery):Boolean;
var
  sqlstr:String;
begin
  sqlstr:='select * from sysobjects where id=object_id('''+tb+''')';
  with query do
    begin
      close;
      sql.Clear;
      sql.Add(sqlstr);
      open;
    end;
  if query.Recordset.EOF then
    IsExist:=False
  else
    IsExist:=True;
end;

//用在Excel中，相当于26进制转换
function int2letter(num:integer):string;
const
  LetterStr='ABCDEFGHIJKLMNOPQRSTUVWXYZ';
var
 i,j:integer;
begin
  if num<=26 then
    begin
      result:=LetterStr[num];
    end
  else
    begin
      j:=num mod 26;
      i:=num div 26;
      if j=0 then
        begin
          j:=26;
          i:=i-1;
        end;
      result:=int2letter(i)+LetterStr[j];
    end;
end;

//是否整型
function IsInt(AStr: string): Boolean;
var
  Value, Code: Integer;
begin
  Val(AStr, Value, Code);
  Result := Code = 0;
end;
//是否浮点型
function IsFloat(AStr: string): Boolean;
var
  Value: Real;
  Code: Integer;
begin
  Val(AStr, Value, Code);
  Result := Code = 0;
end;

下回再来 ：)

procedure RunScreenSave();
//--运行屏幕保护
begin
  SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_SCREENSAVE, 0);
end;

 

//下面两个函数都是四舍五入的，主要是展现一种思路，随便用哪个都可以
function MyRound(Value: Double): integer;
//取整四舍五入
//这个版权归小枫所有
begin
  result:= strtoint(FormatFloat('#',value));
end;

function doRound(Value: Double): integer;
//取整四舍五入
//这个我有一半，呵呵。
begin
  if Value < 0 then Result:= - doRound( -Value )
  else
  Result := round(int((value + 0.5) * 10)) div 10;
end;
//当然，这个函数还有其他的写法，如果你有不同的思路欢迎继续。。。

补充说明：
round这个函数本身采用的是“四舍六入五成双”的法则，虽然更科学，但是实际应用中没有几个用这种规则的。
我也贴几个自己常用的：
{-----------------------------------------------------------------------------
  过程名: Msg
  作者:   Gongqin
  日期:   2003-6-9 16:57:44
  参数:   AMsg : String; ATitle : String='提示'; AType : byte=0; btn : Longint=0
            AType := 1 显示"信息"图标
                      2 显示"错误"图标
             AMsg(显示的消息内容)   ATitle(显示标题)
             btn   := 0 显示 OK
                      1 显示 Ok Cancel
                      2 显示 Yes No
                      3 显示 Retry and Cancel
                      4 显示 Abort, Retry, and Ignore
  返回值: Integer
  说明：  显示消息对话框
-----------------------------------------------------------------------------}
function Msg(AMsg: String;ATitle: String;AType: byte;btn: Longint): Integer;
var Flag : Longint;
begin
  case AType of
    1: Flag := MB_ICONQUESTION; //提问
    2: Flag := MB_ICONERROR; //Error
    3: Flag := MB_ICONSTOP;  //Stop
  else
    Flag := MB_ICONWARNING;
  end;
  case btn of
    0 : Flag := Flag + MB_OK;
    1 : Flag := Flag + MB_OKCANCEL;
    2 : Flag := Flag + MB_YESNO;
    3 : Flag := Flag + MB_YESNOCANCEL;
    4 : Flag := Flag + MB_RETRYCANCEL;
    5 : Flag := Flag + MB_ABORTRETRYIGNORE;
  end;
  result := Application.MessageBox(pchar(AMsg), pchar(ATitle), Flag);
end;

{-----------------------------------------------------------------------------
  过程名: getAppPath
  作者:   Gongqin
  日期:   2003-6-9 17:01:17
  参数:   None
  返回值: string
  说明：  取应用程序的路径
          如果只用ExtractFilePath(ExtractFilePath(application.Exename))取路径
          可能出错，所以加了处理
-----------------------------------------------------------------------------}
function getAppPath : string;
var
  strTmp : string;
begin
  strTmp := ExtractFilePath(ExtractFilePath(application.Exename));
  if strTmp[length(strTmp)] <> '/' then
    strTmp := strTmp + '/';
  result := strTmp;
end;
下面是我自己整理的
http://www.myf1.net/bbs/dispbbs.asp?boardID=5&ID=215239
//计算当前日期所在的季度的第一个月份和最后一个月份
//终极版
function QuarterBegin( TheDate : TDateTime = 0 ) : Integer;
//Copy Right 549@18:25 2003-9-3
begin
  Result := ( Quarter( TheDate ) - 1 ) * 3 + 1;
end;

function QuarterEnd( TheDate : TDateTime = 0 ) : Integer;
//Copy Right 549@18:25 2003-9-3
begin
  Result := ( Quarter( TheDate ) - 1 ) * 3 + 3;
end;

function Quarter( TheDate : TDateTime = 0 ) : Integer;
//Copy Right 549@10:06 2003-9-5
begin
  Result := MonthOf( TheDate );
  if TheDate = 0 then Result := MonthOf( Date );
  Result := ( Result + 2 ) div 3;
end;