Delphi繼承的寫法

底下的連結提供了相當多的解法，有時需要改裝一下TCustomForm時可以來參考使用。

資料來源：Delphi/pascal: overloading a constructor with a different prototype

Delphi 2009 raises Exception in DBX: Unknown Driver XXX

在Design Mode下使用TSQLConnection，設定完成後也可以正常連線，可是在Runtime硬是出現「Unknown Driver: MSSQL」。

其實這只要在uses區手動加入「DBXDynalink」，就可以用了。

資料來源：Delphi 2009 raises Exception "Unknown Driver: Devart..."

EAccessViolation in function CreateProcess in Delphi 2009

很有趣的，我也遇到了這件事情，明明 CreateProcess 這函式在Delphi 7時就正常，到了Delphi 2009就出怪手了。

原因就是出在Unicode……解法轉貼如下：

DBGrid scrolling (滾動條事件) 生成

C++ Builder的DBGrid比較麻煩，可以的話還是從Delphi建一個後再使用帶入使用吧。

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/* JDBGrid.h文件内容 */ //------------------------------------------------------------------------- #ifndef JDBGridH #define JDBGridH //------------------------------------------------------------------------- #include <SysUtils.hpp> #include <Classes.hpp> #include <Controls.hpp> #include <DBGrids.hpp> #include <Grids.hpp> //------------------------------------------------------------------------- class PACKAGE TJDBGrid : public TDBGrid { enum TDBGridOption{ dgEditing, dgAlwaysShowEditor, dgTitles, dgIndicator, dgColumnResize, dgColLines, dgRowLines, dgTabs, dgRowSelect, dgAlwaysShowSelection, dgConfirmDelete, dgCancelOnExit, dgMultiSelect ,dgThumbTracking,dgMouseWheel}; typedef Set<TDBGridOption,dgEditing,goThumbTracking> TDBGridOptions; private: TDBGridOptions FOptions; protected: TWndMethod DBGridProc; TWndMethod DBInplaceEditProc; virtual void __fastcall JDBInplaceEditProc(Messages::TMessage &Message); virtual void __fastcall JDBGridProc(Messages::TMessage& Message); virtual Grids::TInplaceEdit* __fastcall CreateEditor(void); void __fastcall SetOptions(TDBGridOptions Value); public: __fastcall TJDBGrid(TComponent* Owner); __published: __property TDBGridOptions Options = {read=FOptions, write=SetOptions,default=27901}; }; //------------------------------------------------------------------------- #endif /* JDBGrid.cpp文件内容 */ //------------------------------------------------------------------------- #include <vcl.h> #pragma hdrstop #include "JDBGrid.h" #pragma package(smart_init) //------------------------------------------------------------------------- static inline void ValidCtrCheck(TJDBGrid *) { new TJDBGrid(NULL); } //------------------------------------------------------------------------- fastcall TJDBGrid::TJDBGrid(TComponent* Owner):TDBGrid(Owner) { short *shortTmp; Dbgrids::TDBGridOptions optionsTmp; (void*)shortTmp=(void*)&FOptions; *shortTmp=27901; (void*)shortTmp=(void*)&optionsTmp; *shortTmp=3325; TDBGrid::Options=optionsTmp; DBGridProc=WindowProc; WindowProc=JDBGridProc; } //------------------------------------------------------------------------- void __fastcall TJDBGrid::SetOptions(TDBGridOptions Value) { short *pValue,*pOp,*pFOp,saveValue; Dbgrids::TDBGridOptions DBGridOptions; (void*)pValue=(void*)&Value; (void*)pOp=(void*)&DBGridOptions; (void*)pFOp=(void*)&FOptions; *pOp=*pValue & 0x1fff; TDBGrid::Options=DBGridOptions; DBGridOptions=TDBGrid::Options; *pFOp=*pOp | (*pValue & 0x6000); } //------------------------------------------------------------------------- void __fastcall TJDBGrid::JDBInplaceEditProc(Messages::TMessage &Message) { switch (Message.Msg) { case WM_MOUSEWHEEL: if(Options.Contains(dgMouseWheel)) { if (DataLink->Active) { if (Message.WParam<0) { if (DataLink->DataSet->RecNo<DataLink->DataSet->RecordCount) DataLink->DataSet->RecNo++; } else { if (DataLink->DataSet->RecNo>1) DataLink->DataSet->RecNo--; } } if (!Options.Contains(dgAlwaysShowEditor)) EditorMode=false; return; } break; } DBInplaceEditProc(Message); } //------------------------------------------------------------------------- Grids::TInplaceEdit* __fastcall TJDBGrid::CreateEditor(void) { TInplaceEdit *tmp; tmp=TDBGrid::CreateEditor(); DBInplaceEditProc=tmp->WindowProc; tmp->WindowProc=JDBInplaceEditProc; return tmp; } //------------------------------------------------------------------------- void __fastcall TJDBGrid::JDBGridProc(Messages::TMessage& Message) { switch (Message.Msg) { case WM_VSCROLL: case WM_HSCROLL: if (Options.Contains(dgThumbTracking)) if (Message.WParamLo==5) { DBGridProc(Message); Message.WParamLo=4; DBGridProc(Message); Message.WParam=8; } break; case WM_MOUSEWHEEL: if(Options.Contains(dgMouseWheel)) { DBGridProc(Message); if (DataLink->Active) { if (Message.WParam<0) { if (DataLink->DataSet->RecNo<DataLink->DataSet->RecordCount) DataLink->DataSet->RecNo++; } else { if (DataLink->DataSet->RecNo>1) DataLink->DataSet->RecNo--; } } if (!Options.Contains(dgAlwaysShowEditor)) EditorMode=false; return; } break; } DBGridProc(Message); } //------------------------------------------------------------------------- namespace Jdbgrid { void __fastcall PACKAGE Register() { TComponentClass classes[1] = {__classid(TJDBGrid)}; RegisterComponents("Samples", classes, 0); } } //-------------------------------------------------------------------------

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/* 技巧三，行列不同颜色时，交叉部位颜色的设置。 如图：在交叉部位使用行列颜色的alpha混合。 响应TDBGrid的OnDrawColumnCell事件如下：*/ void __fastcall TForm1::JDBGrid1DrawColumnCell(TObject *Sender, const TRect &Rect, int DataCol, TColumn *Column, TGridDrawState State) { int recordNo,tmpInt; if (JDBGrid1->DataSource->DataSet->Active) { recordNo=DataCol=JDBGrid1->DataSource->DataSet->RecNo % 10; if (recordNo ==0 || recordNo>5 ) JDBGrid1->Canvas->Brush->Color=0xb0b0ff; else JDBGrid1->Canvas->Brush->Color=0xffe0e0; tmpInt=Column->Color; if (tmpInt!=clWindow) { int R1,G1,B1,R2,G2,B2,rgbTmp; int alpha=60; rgbTmp=JDBGrid1->Canvas->Brush->Color; R1=tmpInt & 0xff; G1=(tmpInt & 0xff00)>>8; B1=(tmpInt & 0xff0000)>>16; R2=rgbTmp & 0xff; G2=(rgbTmp & 0xff00)>>8; B2=(rgbTmp & 0xff0000)>>16; R1=(R1*alpha+R2*(256-alpha))>>8; G1=(G1*alpha+G2*(256-alpha))>>8; B1=(B1*alpha+B2*(256-alpha))>>8; JDBGrid1->Canvas->Brush->Color=(TColor)(R1+(G1<<8)+(B1<<16)); } JDBGrid1->Canvas->FillRect(Rect); } JDBGrid1->DefaultDrawColumnCell(Rect,DataCol,Column,State); }

Delphi就相當簡單，直接繼承就可以用了。

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uses Message; type TDBGrid = class(DBGrids.TDBGrid) private procedure WmVScroll(var Message: TWMVScroll); message WM_VSCROLL; end; TForm1 = class(TForm) DBGrid1: TDBGrid; .. implementation procedure TDBGrid.WmVScroll(var Message: TWMVScroll); begin if Message.ScrollCode = SB_THUMBTRACK then Message.ScrollCode := SB_THUMBPOSITION; inherited; end;

如此一來，DBGrid的滾動條在拉動的過程中，DataSet的RecNo也會跟著一起調整，十分好用的小技巧。

參考來源：

TDBGRID一些小技巧
Delphi dbgrid continuous scrolling
Winapi.Messages.TWMVScroll

Enabling Virtual Space mode use Notepad++

Delphi有個很好用的編輯功能：

我不會解釋……就是不管上下行字數有無相同，在按了上下鍵後游標都會在同一個位置上下跑。

我一直以為好用的Editor都應該會有這個功能，後來才發現……Notepad++沒有！

之後好久好久終於在Visual Studio看到了這個功能，中文名詞是：
「啟用虛擬空間」
英文是"Enabling Virtual Space mode"

後來在這個討論串中找到解法，節錄內容如下：

Sort of a hack (sends a window message directly to the Scintilla edit control on startup), but works great:

1. Install NppExec plugin
2. Go to Plugins -> NppExec -> Execute
3. Enter the following code:
   

   // ensure console stays hidden
   NPP_CONSOLE 0
   
   // enable virtual spaces (cursor past end of line) outside column edit mode
   SCI_SENDMSG 2596 3 0
   
   // SCI_SENDMSG == send message to Scintilla edit control
   // 2596 == the message we're sending is SCI_SETVIRTUALSPACEOPTIONS
   // 3 == send the value (SCVS_RECTANGULARSELECTION | SCVS_USERACCESSIBLE)
   // the default value is 1 (just SCVS_RECTANGULARSELECTION) for
   //   virtual spaces in column select mode only
   // you can find these values by poking around the source code a bit, or
   // see http://www.scintilla.org/ScintillaDoc.html
   

4. Click the Save button at the bottom, and give the script a name
5. Now go to Plugins -> NppExec -> Advanced Options
6. On the right, under "Execute this script when Notepad++ starts", select the script name you just saved
7. Click OK, close/reopen Notepad++, and enjoy ;)

這方面還是外國人厲害啊！讚！

NotePad++ for MetaEditor

『Expert advisor』は、おもしろい！: Notepad++ de MQL4: 『 秀丸エディタをMQL4エディタ（MetaEditor）にする方法 』と言う記事を読んで、面白そうだったのでNotepad++でやってみました。実施範囲は、自動補完・ハイライト・コンパイル作業です。 初めに Notepad++とは notepad++の導入方法な...


很實用的教學  Notepad++也可以寫+編譯MQL4的檔案了！

整理一下資料，方便自己以後使用：

Thread開發的三兩事

Thread，顧名思義，是很細的線，千萬不要讓大象踩上去。

讓貓自己去玩Thread，必要的時侯請先保護好自己的東西(Synchronize,TCriticalSection,Lock...etc)，
再拿不會壞的玩具(Base Type)和牠玩一下下。

玩太久人(UI)會呆掉，所以主要原則就是讓牠自己玩。