Multiple Line Addition in TMEMO

Question

I am having one Delphi XE2 Project with 2 Buttons (Button1, Button2) and 1 Memo (Memo1).

My requirement is that on Button1 Click Some Text will be witten to Memo1 in the First Line (Line1). If I click again on Button1 Some New Text will be written in a New Line (Line2).

If I click on Button2 the Another New Text will be appended in Memo1 (After Last Line a new Line will be created). So I have written the following code :

procedure TForm1.Button1Click(Sender: TObject);
begin
  Memo1.Lines.Text :='Line1';
  Memo1.Lines.Text :='Line2';
end;
....
....
....
....
procedure TForm1.Button2Click(Sender: TObject);
begin
  Memo1.Lines.Text :='Line3';
  Memo1.Lines.Text :='Line4';
end;

But the problem is that only one line is showing with text as "Line1" on Button1FirstClick, "Line2" on Button1SecondClick and "Line4" on Button2Click. Please help me.

Answer 1

To add more text to a memo control, call either Append or Add, like this:

procedure TForm1.Button1Click(Sender: TObject);
begin
  Memo1.Lines.Add('Line1');
  Memo1.Lines.Add('Line2');
end;
....
....
....
....
procedure TForm1.Button2Click(Sender: TObject);
begin
  Memo1.Lines.Add('Line3');
  Memo1.Lines.Add('Line4');
end;

If you need to clear the contents...

Memo1.Lines.Clear;

And if you wish to replace a line (only if the index already exists):

Memo1.Lines[2]:= 'Replacement Text';

To delete one of the lines...

Memo1.Lines.Delete(2);

Answer 2

TMemo.Lines is an object of type TStrings that has many string handling capabilities. Assigning the Text property rewrites all strings it contains.

You can add a single line after all other already present lines with:

Memo.Lines.Add('Text');

You can insert a line (at fourth position) with:

Memo.Lines.Insert(3, 'Text');

And you can add multiple lines:

Memo.Lines.Add('Line1'#13#10'Line2');
Memo.Lines.AddStrings(ListBox.Lines);