小编S.F*_*TEH的帖子

这是我生成集合的所有可能组合的简单代码

1,2,3:

• 显示:123 132 213 231 312 321

我想创建可变数量的for循环让用户确定给定字符串的长度...

有没有人有想法......

提前致谢.

type
  TNumber = '0'..'9';

procedure TForm1.Button1Click(Sender: TObject);
var
  Numbers: array[0..3] of TNumber;
  a, b, c, d: Integer;
  s: string;
begin
  Numbers[0] := '1';
  Numbers[1] := '8';
  Numbers[2] := '7';
  Numbers[3] := '2';
  for a := low(Numbers) to High(Numbers) do
    for b := low(Numbers) to High(Numbers) do
      for c := low(Numbers) to High(Numbers) do
        for d := low(Numbers) to High(Numbers) do
        begin
          s := Numbers[a] + Numbers[b] + Numbers[c]  + …

我使用以下代码将PNG图像存储到Ini文件中:

procedure TfrmParametres.SaveIni;
var
  IniFile: TIniFile;
  MS: TMemoryStream;
  PNG: TPngImage;
begin
  IniFile := TIniFile.Create(IniFileName);
  try
  PNG := TPngImage.Create;
  try
    PNG.LoadFromFile(edtLogo.Text);//edtlogo contain image file path
    MS  := TMemoryStream.Create;
    try
      PNG.SaveToStream(MS);
      MS.Seek(0, 0);
      IniFile.WriteBinaryStream('REPORT_HEADER', 'LOGO', MS);
    finally
      MS.Free;
    end;
  finally
    PNG.Free;
  end;
finally
  FreeAndNil(IniFile);
end;
end;

并以另一种形式显示图片OnShow事件我使用相同的方法:

1. 在TMemoryStream对象中加载DATA
2. 将MemoryStream中的DATA加载到TPngImage对象中

3. 在TImage组件中显示图片

   procedure TfrmLoadPicture.FormShow(Sender: TObject);
   var
     IniFile: TIniFile;
     MS: TMemoryStream;
     PNG: TPngImage;
   begin
     IniFile:= TIniFile.Create(frmParametres.IniFileName);
     try
       MS:= TMemoryStream.Create;
       try
         IniFile.ReadBinaryStream('REPORT_HEADER', 'LOGO', MS);
         PNG := TPngImage.Create;
         try
           MS.Seek(0, 0);
           PNG.LoadFromStream(MS);
           Image.Picture.Assign(PNG);
         finally
           PNG.Free;
         end;
       finally …

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我有ObjectList容器,我想添加一个内部迭代器(访问者模式)实际上我正在尝试确定我的列表中的重复项.

样本:http://pastebin.com/pjeWq2uN

这段代码提供了我正在努力实现的目标.

TFindDuplicatesMethod = procedure(s1, s2: string) of object;

TPersonList = class(TObjectList)
public
  procedure Iterate(pMethode: TFindDuplicatesMethod)
end;

procedure TPersonList.Iterate(pMethode: TFindDuplicatesMethod)
var
  i: Integer;
begin
  for i := 0 to Count - 1 do
  pMethode(TMyClass(Items[i]).S1, {But i don't have the second parameter because
                               it comes from outside of PersonList Ex: OpenDialog.Files[i]})
end;

function FindDuplicate(S1, S2: string): Boolean;
begin
  Result := False;
  if S1 = S2 then
  Result := True;
end;

begin
  Files.Iterate(FindDuplicates(S1, S2));
end;

我想知道OOP如何解决这个问题.

提前致谢...