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Delphi 1
Ограничение размера Memo
Ограничение длины и количества строк компонента:
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unit Unit1; interface uses SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics, Controls,
StdCtrls, ExtCtrls, Forms;
type TForm1 = class(TForm)
Memo1: TMemo;
procedure FormCreate(Sender: TObject);
procedure Memo1KeyPress(Sender: TObject; var Key: Char);
public
MaxCharsPerLine, MaxLines: Integer;
function MemoLine: Integer;
function LineLen(r: Integer): Integer;
function NRows: Integer;
end;
var Form1: TForm1;
implementation {$R *.DFM} function TForm1.NRows: Integer; begin with Memo1 do
Result := 1 + SendMessage(Handle, EM_LINEFROMCHAR, GetTextLen-1, 0);
end;function TForm1.LineLen(r: Integer): Integer; var r1, r2: Integer; begin with Memo1 do begin
r1 := SendMessage(Handle, EM_LINEINDEX, r, 0);
if (r > NRows-1) then
r2 := SendMessage(Handle, EM_LINEINDEX, r+1, 0)-2 {-CR/LF}
else
r2 := GetTextLen;
end;
Result := r2-r1;
end;function TForm1.MemoLine: Integer; begin with Memo1 do
Result := SendMessage(Handle, EM_LINEFROMCHAR, SelStart, 0);
end;procedure TForm1.FormCreate(Sender: TObject); begin MaxCharsPerLine := 8;
MaxLines := 4;
end;procedure TForm1.Memo1KeyPress(Sender: TObject; var Key: Char); begin with Memo1 do begin
case Key of
' '..#255: if (LineLen(MemoLine) >= MaxCharsPerLine) then
Key := #0;
#10, #13: if (NRows >= MaxLines) then
Key := #0;
#8: if (SelStart = SendMessage(Handle, EM_LINEINDEX, MemoLine, 0)) then
Key := #0;
end;
end;
end;end. |
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