t := ReadAstr(Fp); FFieldCount := ReadAInteger(Fp); FRecordCount := ReadAInteger(Fp); if ReadAChar(Fp) <> ''''@'''' then showmessage(''''GetHead File Error''''); end;
procedure TIbStorage.GetFieldNames(Fp: TFileStream); var Ch: Char; Str: string; begin Str := ''''''''; Str := ReadAStr(Fp); FFieldNames.CommaText := Str; Ch := ReadAChar(Fp); if Ch <> ''''@'''' then Showmessage(''''When get fieldnames Error''''); end;
procedure TIbStorage.GetIndex(Fp: TFileStream); var Ch: Char; Str: string; begin Str := ''''''''; Str := ReadAStr(Fp); FStreamIndex.CommaText := Str; Ch := ReadAChar(Fp); if Ch <> ''''@'''' then Showmessage(''''When Get Field Position Index Error''''); end;
//---------Read Field''''s Value Part function TIbStorage.GetFieldValue(ARecordNo, FieldNo: Integer): string; var Id, T : string; Pos: Integer; Len, I : Integer; Er: Boolean; begin Result := ''''''''; Er := False; if ARecordNo > FRecordCount then Er := true; //ARecordNo := FRecordCount; if ARecordNo < 1 then Er := True; // ARecordNo := 1; if FieldNo >= FFieldCount then Er := True; // FieldNo := FFieldCount - 1; if FieldNo < 0 then Er := True; //FieldNo := 0; if Er then begin Showmessage(''''记录号或者字段标号越界''''); Exit; end; if FFieldCount = 0 then Exit; Id := Inttostr(ARecordNO) + ''''_'''' + IntToStr(FieldNo); Pos := StrToInt(FStreamIndex.Values[Id]); FStream.Position := Pos; //取得字段内容的长度 Len := ReadAInteger(FStream); if Len > 0 then Result := ReadBStr(FStream, Len); if ReadAChar(FStream) <> ''''@'''' then Showmessage(''''When Read Field, Find Save Format Error''''); end;
procedure TIbStorage.FieldStream(ARecordNo, FieldNo: Integer; var AStream: TStream); var Id, T : string; Pos: Integer; Len, I : Integer; Er: Boolean; begin Er := False; if ARecordNo > FRecordCount then Er := true; //ARecordNo := FRecordCount; if ARecordNo < 1 then Er := True; // ARecordNo := 1; if FieldNo >= FFieldCount then Er := True; // FieldNo := FFieldCount - 1; if FieldNo < 0 then Er := True; //FieldNo := 0; if Er then begin TDsException.Create(''''GetFieldValue函数索引下标越界''''); Exit; end; if FFieldCount = 0 then Exit; Id := Inttostr(ARecordNO) + IntToStr(FieldNo); Pos := StrToInt(FStreamIndex.Values[Id]); FStream.Position := Pos; Len := ReadAInteger(FStream); AStream.CopyFrom(FStream, Len); end;
function TIbStorage.GetFieldName(AIndex: Integer): string; //取得字段名称 begin //存储的字段和数据类型各占一半 if ((AIndex < 0) or (AIndex >= FFieldNames.Count div 2)) then Application.MessageBox('''' 取字段名索引越界'''', ''''程序 错误'''', Mb_Ok + Mb_IconError) else Result := FFieldNames.Names[AIndex*2]; end;
function TIbStorage.GetFieldDataType(AIndex: Integer): TFieldType; //取得字段名称 begin //存储的字段和数据类型各占一半 if ((AIndex < 0) or (AIndex >= FFieldNames.Count div 2)) then Application.MessageBox('''' 取字段数据类型索引越界'''', ''''程序 错误'''', Mb_Ok + Mb_IconError) else Result := TFieldType(StrToInt(FFieldNames.Values[FFieldNames.Names[AIndex*2+1]])); end;
function TIbStorage.GetDisplayLabel(AIndex: Integer): string; //取得字段显示名称 begin if ((AIndex < 0) or (AIndex >= FFieldNames.Count)) then Application.MessageBox('''' 取字段名索引越界'''', ''''程序 错误'''', Mb_Ok + Mb_IconError) else Result := FFieldNames.Values[GetFieldName(AIndex)]; end;
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