我正在嘗試在現有 .txt 檔案中的一定數量的條目之后創建一個新的 .txt 檔案。例如，我想在我的檔案中有 50 個條目，然后，我想創建一個新檔案，并且這些條目在該新檔案中繼續存在。假設我不希望我的日志檔案被很多行填充，而是有更多的 .txt 檔案來劃分條目??。
這是我的示例代碼：
procedure TForm1.Button3Click(Sender: TObject);
function CountRows(Afilename: string): integer;
var
f: TextFile;
i: integer;
begin
assignfile(f, afilename);
reset(f);
result := 0;
while not eof(f) do
begin
readln(f);
inc(result);
end;
closefile(f);
end;
var
f: TextFile;
fileName: String;
fs: Tformatsettings;
begin
fs.shortdateformat := 'DD.MM.YYYY';
fs.TimeSeparator := ':';
filename := 'D:\LogLprf\LogLpFr ' Datetostr(now, fs) '.txt';
assignfile(f, filename);
if FileExists(filename) then
begin
if CountRows(filename)>=2 then
begin
filename := 'D:\LogLprf\LogLpFr ' Datetostr(now, fs) '1.txt';
assignfile(f, filename);
rewrite(f);
end
else
append(f);
end
else
begin
rewrite(f);
end;
fs.ShortDateFormat := 'DD.MM.YYYY HH:mm:ss';
Writeln(f, datetimetostr(now, fs) '- ' 'Some error...');
closefile(f);
end;
使用上面的代碼，我設法創建第一個檔案并在第一個檔案中達到條目限制時創建第二個檔案。但是，第二個檔案每次都會重新創建。我知道那是因為我正在打電話rewrite(f)，但我需要在前一個檔案的條目到達結尾后創建一個新的 .txt 檔案。我也嘗試過呼叫fileexists(filename)afterCountRows(filename)但這不是一個好的解決方案，因為我會有很多嵌套的 if 陳述句，如果我們需要創建很多 .txt 檔案，這將無法解決問題。我也嘗試過回圈，但這也不能解決問題。歡迎提出任何建議...謝謝
uj5u.com熱心網友回復：
當您定義檔案名時，您使用的是DateToStr，它只將日期資訊添加到您的檔案名中。因此，如果您嘗試在一天內多次創建新檔案名，您將始終獲得相同的檔案名，因為DateToString每次都會回傳相同的結果。
DateToString您應該使用DateTimeToString而不是使用，因為這還會在結果中包含時間資訊，從而允許您在同一天創建多個不同的檔案名。除非您需要在一秒鐘內創建多個新檔案名，否則您不會有任何問題。
另一種方法是對檔案進行遞增編號，以便每個檔案名最后都包含一個唯一編號。
您可以在此處找到有關如何實作此目的的解決方案
或者，如果您需要更用戶友好的檔案命名系統，您也可以將您的方法與自動增量編號方法結合使用。
uj5u.com熱心網友回復：
請查看我找到的代碼作為非常適合我的解決方案......在所有評論和發布我的問題的人的幫助下：
procedure TForm1.Button5Click(Sender: TObject);
function SearchFiles(SearchDir, SearchFile:string):String;
var
SearchRec: TSearchRec;
begin
if FindFirst(SearchDir SearchFile, faAnyfile, SearchRec)=0 then
begin
repeat
result := SearchRec.Name
until (findnext(SearchRec)<>0);
end;
FindClose(SearchRec);
end;
function GetFilesCount(SearchDir, SearchFile : String) : Integer;
var
SearchRec: TSearchRec;
begin
Result := 0;
if FindFirst(SearchDir SearchFile, faAnyFile xor faDirectory, SearchRec)= 0 then
begin
repeat
Inc(Result);
until (FindNext(SearchRec) <> 0);
FindClose(SearchRec);
end;
end;
var
FileCont: TStringList;
f:textfile;
FileName, S: String;
fs: Tformatsettings;
SearchRec: TSearchRec;
i:integer;
begin
FileCont := TStringList.Create;
try
fs.shortdateformat := 'DD.MM.YYYY';
fs.TimeSeparator := ':';
if SearchFiles(Extractfilepath(application.ExeName),'LogLpFr ' datetostr(now,fs) ' .txt') = '' then
begin
Filename := Extractfilepath(application.ExeName) 'LogLpFr ' Datetostr(Now, fs) ' .txt';
filecont.SaveToFile(filename);
end
else
Filename := Extractfilepath(application.ExeName) SearchFiles(Extractfilepath(application.ExeName),'LogLpFr ' datetostr(now,fs) ' *.txt');
FileCont.LoadFromFile(FileName);
if FileCont.Count >=2 then
begin
i := GetFilesCount(Extractfilepath(application.ExeName),'LogLpFr ' datetostr(now,fs) ' *.txt');
Filename := Extractfilepath(application.ExeName) 'LogLpFr ' Datetostr(Now, fs) ' ' i.ToString '.txt';
FileCont.Clear();
end;
fs.ShortDateFormat := 'DD.MM.YYYY HH:mm:ss';
S := DateTimeToStr(Now(), fs) '- ' 'Some error...';
FileCont.Add(S);
FileCont.SaveToFile(Filename);
finally
FileCont.Free();
end;
end;
我使用了GetFilesCount@Ehab 提供的一個函式，并添加了一個類似SearchFiles的函式，它將搜索所有檔案并確保最后一個檔案是我們用于撰寫的檔案。（我最初的問題是，在我的第一個代碼中，我總是使用同一個檔案......）感謝所有幫助......
uj5u.com熱心網友回復：
今天我有一個毀壞的Delphi7，所以這是一個完整的作業示例。
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;
type
TForm1 = class(TForm)
Btn1: TButton;
Memo1: TMemo;
procedure Btn1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
//Just a sample class not a production one
//Each day has log files Like 21.12.2022_0001.txt, 21.12.2022_0002.txt, ...
TSampleLoger = class
private
procedure SetWorkPath(const Value: string);
procedure SetMaxLinesPerFile(const Value: Integer);
protected
FileCont: TStringList;
Fs: TFormatsettings;
FWorkPath : string;
FLastFile : string;
FFilesCount : Integer;
FMaxLinesPerFile: Integer;
//Make a full file name without extension eg.
//(D:\LogLprf\21.12.2022)
function MakeBaseFileName() : string;
//Updates FLastFile & FFilesCount and returns New file name
function MakeNewFileName() : string;
//Make a full file name without extension eg.
//(D:\LogLprf\21.12.2022_0099.txt)
function MakeFileName(C : Integer) : string;
//Returns Today last used log file if exists
function GetLastFileName(): string;
//Returns Files count for a specific date and last file used for that day
//SearchFile Param. Value will be like [D:\LogLprf\21.12.2022_*.txt]
function GetFilesCount(SearchFile : String; var LastFileName:String) : Integer;
public
constructor Create(APath:string); reintroduce;
destructor Destroy; override;
procedure WriteToLog(Msg:String);
property LastFile : string read GetLastFileName;
property WorkPath : string read FWorkPath write SetWorkPath;
property MaxLinesPerFile : Integer read FMaxLinesPerFile write SetMaxLinesPerFile;
end;
var
Form1: TForm1;
實施部分
implementation
{$R *.dfm}
function TSampleLoger.GetFilesCount(SearchFile : String; var LastFileName:String) : Integer;
var
SearchRec: TSearchRec;
begin
//Initial values
Result := 0;
LastFileName := '';
if FindFirst(SearchFile, faAnyFile xor faDirectory, SearchRec)= 0 then
begin
repeat
Inc(Result);
LastFileName := SearchRec.Name;
until (FindNext(SearchRec) <> 0);
Windows.FindClose(SearchRec.FindHandle);
end;
end;
constructor TSampleLoger.Create(APath: string);
begin
inherited Create();
WorkPath := APath;
FileCont := TStringList.Create;
FFilesCount := 0;
FMaxLinesPerFile := 50;
end;
function TSampleLoger.GetLastFileName: string;
var
S : string;
begin
if FLastFile = '' then
begin
S := MakeBaseFileName() '_*.txt';
FFilesCount := GetFilesCount(s, FLastFile);
FLastFile := FWorkPath FLastFile;
end;
Result := FLastFile;
end;
function TSampleLoger.MakeBaseFileName() : string;
var
Path : string;
begin
Fs.ShortDateformat := 'DD.MM.YYYY';
Result := FWorkPath Datetostr(Date(), Fs);
end;
function TSampleLoger.MakeNewFileName() : string;
begin
Inc(FFilesCount);
FLastFile := MakeFileName(FFilesCount);
Result := FLastFile;
end;
procedure TSampleLoger.WriteToLog(Msg:String);
var
FileName, S: String;
begin
FileName := GetLastFileName();
//Do we have a file for today?
if FileName <> '' then
begin
//Load file contents
FileCont.LoadFromFile(FileName);
//Get ready to start new file if we reached the Maximum line count per file
if FileCont.Count >= FMaxLinesPerFile then
FileName := '';
end;
//Start new file if we don't have one
if FileName = '' then
begin
FileName := MakeNewFileName();
FileCont.Clear();
end;
Fs.TimeSeparator := ':';
Fs.ShortDateFormat := 'DD.MM.YYYY HH:mm:ss';
S := DateTimeToStr(Now(), Fs) '- ' Msg;
FileCont.Add(S);
FileCont.SaveToFile(Filename);
end;
procedure TSampleLoger.SetWorkPath(const Value: string);
begin
FWorkPath := Value;
if FWorkPath[Length(FWorkPath)] <> '\' then
FWorkPath := FWorkPath '\';
end;
function TSampleLoger.MakeFileName(C: Integer): string;
const
Fmt = '_%4.4U.txt';
begin
//add counter and extension to file name
Result := MakeBaseFileName() Format(Fmt,[C]);
end;
destructor TSampleLoger.Destroy;
begin
FileCont.Free();
inherited;
end;
procedure TSampleLoger.SetMaxLinesPerFile(const Value: Integer);
begin
FMaxLinesPerFile := Value;
//At least one line per file
if FMaxLinesPerFile < 1 then
FMaxLinesPerFile := 1;
end;
procedure TForm1.Btn1Click(Sender: TObject);
var
Logger : TSampleLoger;
i : Integer;
S : string;
begin
Logger := TSampleLoger.Create('D:\LogLprf\');
try
for i := 1 to 320 do
begin
//Write a randome Msg to log
S := 'Error ' IntToStr(GetTickCount());
Logger.WriteToLog(S);
Memo1.Lines.Add(Logger.LastFile ' === ' S);
Application.ProcessMessages();
end;
finally
Logger.Free();
end;
end;
end.
uj5u.com熱心網友回復：
我現在沒有運行環境來測驗您的代碼，但我認為您可以嘗試類似的方法：
function GetFilesCount(SearchDir, SearchFile : String) : Integer;
var
SearchRec: TSearchRec;
begin
Result := 0;
if FindFirst(SearchDir SearchFile, faAnyFile xor faDirectory, SearchRec)= 0 then
begin
repeat
Inc(Result);
until (FindNext(SearchRec) <> 0);
Windows.FindClose(SearchRec.FindHandle);
end;
end;
procedure TForm1.Btn3Click(Sender: TObject);
var
FileCont: TStringList;
FileName, S: String;
fs: Tformatsettings;
C : Integer;
begin
FileCont := TStringList.Create;
try
fs.shortdateformat := 'DD.MM.YYYY';
fs.TimeSeparator := ':';
FileName := 'D:\LogLprf\LogLpFr ' Datetostr(Now(), fs) '.txt';
if FileExists(FileName) then
begin
FileCont.LoadFromFile(FileName);
if FileCont.Count >=2 then
begin
//Count previous log files.
C := GetFilesCount('D:\LogLprf\', 'LogLpFr*.txt');
Inc(C);
Filename := 'D:\LogLprf\LogLpFr ' Datetostr(Now(), fs) IntToStr(C) '.txt';
FileCont.Clear();
end;
end;
fs.ShortDateFormat := 'DD.MM.YYYY HH:mm:ss';
S := DateTimeToStr(Now(), fs) '- ' 'Some error...';
FileCont.Add(S);
FileCont.SaveToFile(Filename);
finally
FileCont.Free();
end;
end;
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