文件路径相关的字符串操作

 

根据下面我总结出两个方法经常用到：

ExtractFilePath(paramstr(0));

ExtractFilePath(Application.ExeName);

输出的都是：//C:\Documents and Settings\wy\My Documents\RAD Studio\Projects

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uses
  HTTPApp, Masks;

procedure TForm1.Button1Click(Sender: TObject);
var
  ss,s: string;
begin
  //先提取一个文件名的字符串
  ss := Application.ExeName;
  ShowMessage(ss); //C:\Documents and Settings\wy\My Documents\RAD Studio\Projects\Project1.exe

  //路径
  s := ExtractFilePath(ss);//这个可能经常用到
  ShowMessage(s); //C:\Documents and Settings\wy\My Documents\RAD Studio\Projects\

  //所在文件夹
  s := ExtractFileDir(ss);
  ShowMessage(s); //C:\Documents and Settings\wy\My Documents\RAD Studio\Projects

  //所在逻辑盘
  s := ExtractFileDrive(ss);
  ShowMessage(s); //C:

  //文件名
  s := ExtractFileName(ss);
  ShowMessage(s); //Project1.exe

  //文件扩展名
  s := ExtractFileExt(ss);
  ShowMessage(s); //.exe

  //相对路径
  s := ExtractRelativePath('C:\Documents and Settings\wy\My Documents\',ss);
  ShowMessage(s); //RAD Studio\Projects\Project1.exe

  //dos下的短文件名
  s := ExtractShortPathName(ss);
  ShowMessage(s); //C:\DOCUME~1\wy\MYDOCU~1\RADSTU~1\Projects\Project1.exe

  //转换到Unix路径格式, 需要 uses HTTPApp
  s := DosPathToUnixPath(ss);
  ShowMessage(s); //C:/Documents and Settings/wy/My Documents/RAD Studio/Projects/Project1.exe

  //转Unix路径格式为Window格式, 是 DosPathToUnixPath 的逆操作
  s := ExpandUNCFileName(DosPathToUnixPath(ss));
  ShowMessage(s); //C:\Documents and Settings\wy\My Documents\RAD Studio\Projects\Project1.exe

  //去掉结尾的路径分隔符
  s := ExcludeTrailingPathDelimiter(ExtractFilePath(ss));
  ShowMessage(s); //C:\Documents and Settings\wy\My Documents\RAD Studio\Projects

  //去掉结尾的路径分隔符, 只是调用:ExcludeTrailingPathDelimiter
  s := ExcludeTrailingBackslash(ExtractFilePath(ss));
  ShowMessage(s); //C:\Documents and Settings\wy\My Documents\RAD Studio\Projects

  //更换扩展名, 并不修改文件, 只是替换字符串:
  s := ChangeFileExt(ss,'.bak');
  ShowMessage(s); //C:\Documents and Settings\wy\My Documents\RAD Studio\Projects\Project1.bak

  //更换文件路径:
  s := ChangeFilePath(ss,'c:\temp');
  ShowMessage(s); //c:\temp\Project1.exe

  //判断第几个字符是否是路径分隔符:
  IsPathDelimiter(ss,3); //返回 True

  //判断后缀名是不是 exe; 需要 uses Masks
  MatchesMask(ss,'*.exe'); //返回 True
end;

---

//分解 ProcessPath (需要 uses FileCtrl)
var
  s,p,f: string;
  d: Char;
begin
  s := ParamStr(0);//这个也经常用到
  ShowMessage(s); //C:\Documents and Settings\wy\My Documents\RAD Studio\Projects\Project1.exe
  ProcessPath(s,d,p,f);
  ShowMessage(d); //C
  ShowMessage(p); //\Documents and Settings\wy\My Documents\RAD Studio\Projects
  ShowMessage(f); //Project1.exe
end;

---

//压缩显示 MinimizeName (需要 uses FileCtrl)
var
  s: string;
begin
  s := ParamStr(0);
  s := MinimizeName(s,Self.Canvas,100);
  ShowMessage(s); //C:\...\Project1.exe
end;

---

procedure TForm1.Button1Click(Sender: TObject);
begin
  ShowMessage(ExtractFilePath(ParamStr(0)));          //获取程序所在目录
  ShowMessage(ExtractFilePath(Application.ExeName));  //获取程序所在目录
  ShowMessage(GetCurrentDir + '\');                   //获取当前目录{以后用这个就可以了，上面的两个都可能有点慢,因为都经过了两次转换，里面的代码也很多，从名字上判断第三个是专一函数，}
end;

以后就用第三个了，三个运行出来的结果都一样，但是第三个从名字上判断是专一的函数，前两个 都是 方法中 再次嵌套方法，会造成速度变慢。再加上前两个的主要也不仅仅是程序目录的，前两个 功能很强大应该