在Delphi中,我无法保存备忘录中的SelStart
和SelLength
,当选择为负/反向时,备忘录每5秒更新一次文本。
对于负向/反向选择,我的意思是我已经在某个地方开始选择,并且按住Shift的同时按了向左箭头键几次。
码:
var
caret: TPoint;
sel_start, sel_length: Integer;
begin
sel_start := Memo1.SelStart; // = 5
sel_length := Memo1.SelLength; // = 10
caret := Memo1.CaretPos; // caret.x = 15
//'adi and bl' selected
caret.x := sel_start;
Memo1.Lines.Clear;
Memo1.Lines.Add('laditadi and blah blah');
Memo1.SelStart := sel_start;
Memo1.SelLength := sel_length;
Memo1.CaretPos := caret;
end;
事实是,设置SelLength似乎实际上可以移动插入符号。设置
SelLength
后设置插入符号将使SelLength := 0;
。由于文本不断变化,因此我不能在前后使用TMemo.SelText
/ TMemo.SetSelText
。我找不到保存插入符号位置的方法...任何线索?
最佳答案
如果sel_start具有与插入符号的字符位置相同的值,则通过将selstart设置为selstart + sellength并将sellength设置为-sellength来反转选择。
procedure TForm1.Button1Click(Sender: TObject);
var
caret: TPoint;
sel_start, sel_length,CharFromPos: Integer;
begin
Memo1.SetFocus;
GetCaretPos(Caret);
CharFromPos := SendMessage(Memo1.Handle, EM_CHARFROMPOS, 0 ,Caret.Y*$FFFF + Caret.X) AND $FFFF;
sel_start := Memo1.SelStart; // = 5
sel_length := Memo1.SelLength; // = 10
Memo1.Lines.Clear;
Memo1.Lines.Add('laditadi and blah blah'#13#10'laditadi and blah blah');
if sel_start<>CharFromPos then
begin
Memo1.SelStart := sel_start;
Memo1.SelLength := sel_length;
end
else
begin
Memo1.SelStart := sel_start + sel_length;
Memo1.SelLength := - sel_length;
end;
end;
procedure TForm1.Timer1Timer(Sender: TObject);
var
p:Tpoint;
b:Boolean;
CharFromPos:Integer;
begin
b := GetCaretPos(p);
CharFromPos := SendMessage(Memo1.Handle, EM_CHARFROMPOS, 0 ,p.Y*$FFFF + p.X) AND $FFFF;
Caption := Format('SelStart %d CharFromPos %d',[Memo1.SelStart,CharFromPos])
end;