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TCustomEdit.SelLength Property

Specifies the number of characters (bytes) that are selected.

Pascal
property SelLength: Integer;
C++
__property int SelLength;

Read SelLength to determine the length, in bytes, of the selected text. This is the same as the number of characters, unless you are using a multi-byte character set. Set SelLength to change the selection to consist of the first SelLength bytes starting at SelStart.

Note: Setting SelLength to a value greater than the number of characters from SelStart to the end of the text results in the selection of all characters from SelStart to the end of the text. Reading SelLength immediately after setting it to a value greater than the number of available characters returns the number of characters actually selected, not the value that was just set.
 

C++ Examples: 

 

/*
This example requires a TRichEdit, a TButton, and a 
TFindDialog.  Clicking the button click will display a Find 
Dialog to the right of the edit control.  Filling in the 
"Find what" text and pressing the Find Next button will
select the first matching string in the Rich Edit control 
that follows the previous selection.
*/
void __fastcall TForm1::Button1Click(TObject *Sender)
{
  FindDialog1->Position = Point(RichEdit1->Left + RichEdit1->Width, RichEdit1->Top);
  FindDialog1->Execute();
}

void __fastcall TForm1::FindDialog1Find(TObject *Sender)
{
  int FoundAt, StartPos, ToEnd;
  TSearchTypes mySearchTypes;
  // begin the search after the current selection
  // if there is one
  // otherwise, begin at the start of the text
  if (FindDialog1->Options.Contains(frMatchCase))
    mySearchTypes << stMatchCase;
  if (FindDialog1->Options.Contains(frWholeWord))
    mySearchTypes << stWholeWord;
  if (RichEdit1->SelLength)
    StartPos = RichEdit1->SelStart + RichEdit1->SelLength;
  else
    StartPos = 0;
  // ToEnd is the length from StartPos
  // to the end of the text in the rich edit control
  ToEnd = RichEdit1->Text.Length() - StartPos;
  FoundAt = RichEdit1->FindText(FindDialog1->FindText, StartPos, ToEnd, mySearchTypes);
  if (FoundAt != -1)
  {
    RichEdit1->SetFocus();
    RichEdit1->SelStart = FoundAt;
    RichEdit1->SelLength = FindDialog1->FindText.Length();
  }
  else Beep();
}

void __fastcall TForm1::FormCreate(TObject *Sender)
{
  RichEdit1->PlainText = False;
  RichEdit1->Lines->LoadFromFile("../Overview.RTF");  // starts in Debug
  RichEdit1->ScrollBars = ssVertical;
}
/*
The following OnFind event handler searches a memo component
for the text specified in the FindText property of a find
dialog component. If found, the first occurrence of the text
in Memo1 is selected. The code uses the Pos function to
compare strings, and stores the number of characters to skip
when determining the selection position in the SkipChars
variable. Because there is no handling of case, whole word,
or search direction in this algorithm, it is assumed that
the Options property of FindDialog1 is set to
[frHideMatchCase, frHideWholeWord, frHideUpDown].
*/
void __fastcall TForm1::FindDialog1Find(TObject *Sender)
{
  for (int I = 0; I < Memo1->Lines->Count; I++)
  {
    int PosReturn = Memo1->Lines->Strings[I].Pos(FindDialog1->FindText);
    if (PosReturn) //found!
    {
      int Skipchars = 0;
      for (int J = 0; J < I; J++)
        Skipchars += Memo1->Lines->Strings[J].Length();
      Skipchars += I*2; // add CR/LF for all skipped lines
      Skipchars += PosReturn - 1;
      Memo1->SetFocus();
      Memo1->SelStart = Skipchars;
      Memo1->SelLength = FindDialog1->FindText.Length();
      break;
    }
  }
}

 

Delphi Examples: 

{
This example requires a TRichEdit, a TButton, and a 
TFindDialog.  Clicking the button click will display a Find 
Dialog to the right of the edit control.  Filling in the 
"Find what" text and pressing the Find Next button will 
select the first matching string in the Rich Edit control 
that follows the previous selection.
}
procedure TForm1.Button1Click(Sender: TObject);
begin
  FindDialog1.Position := 
    Point(RichEdit1.Left + RichEdit1.Width, RichEdit1.Top);
  FindDialog1.Execute;
end;

procedure TForm1.FindDialog1Find(Sender: TObject);
var
  FoundAt: LongInt;
  StartPos, ToEnd: Integer;
  mySearchTypes : TSearchTypes;
  myFindOptions : TFindOptions;
begin
  with RichEdit1 do
  begin
    if frMatchCase in FindDialog1.Options then
       mySearchTypes := mySearchTypes + [stMatchCase];
    if frWholeWord in FindDialog1.Options then
       mySearchTypes := mySearchTypes + [stWholeWord];
    { begin the search after the current selection if there is one }
    { otherwise, begin at the start of the text }
    if SelLength <> 0 then
      StartPos := SelStart + SelLength
    else
      StartPos := 0;
    { ToEnd is the length from StartPos to the end of the 
      text in the rich edit control }
    ToEnd := Length(Text) - StartPos;
    FoundAt := 
      FindText(FindDialog1.FindText, StartPos, ToEnd, mySearchTypes);
    if FoundAt <> -1 then
    begin
      SetFocus;
      SelStart := FoundAt;
      SelLength := Length(FindDialog1.FindText);
    end
    else Beep;
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
const Path = 'OverView.RTF';
begin
  RichEdit1.PlainText := False;
  RichEdit1.Lines.LoadFromFile(Path);
  RichEdit1.ScrollBars := ssVertical;
end;
{
The following OnFind event handler searches a memo component
for the text specified in the FindText property of a find
dialog component. If found, the first occurrence of the text
in Memo1 is selected. The code uses the Pos function to
compare strings, and stores the number of characters to skip
when determining the selection position in the SkipChars
variable. Because there is no handling of case, whole word,
or search direction in this algorithm, it is assumed that
the Options property of FindDialog1 is set to
[frHideMatchCase, frHideWholeWord, frHideUpDown].
} 
procedure TForm1.FindDialog1Find(Sender: TObject);
var
  I, J, PosReturn, SkipChars: Integer;
begin
  for I := 0 to Memo1.Lines.Count do
  begin
    PosReturn := Pos(FindDialog1.FindText,Memo1.Lines[I]);
    if PosReturn <> 0 then {found!}
    begin
      SkipChars := 0;
      for J := 0 to I - 1 do
        SkipChars := SkipChars + Length(Memo1.Lines[J]);
      SkipChars := SkipChars + (I*2);
      SkipChars := SkipChars + PosReturn - 1;
      Memo1.SetFocus;
      Memo1.SelStart := SkipChars;
      Memo1.SelLength := Length(FindDialog1.FindText);
      Break;
    end;
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
const Path = 'country.list';
begin
  Memo1.Lines.LoadFromFile(Path);
end;

 

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