How do I include a newline character in a string i

问题:

I want to create a string that spans multiple lines to assign to a Label Caption property. How is this done in Delphi?

回答1:

In the System.pas (which automatically gets used) the following is defined:

const
  sLineBreak = {$IFDEF LINUX} AnsiChar(#10) {$ENDIF} 
               {$IFDEF MSWINDOWS} AnsiString(#13#10) {$ENDIF};

This is from Delphi 2009 (notice the use of AnsiChar and AnsiString). (Line wrap added by me.)

So if you want to make your TLabel wrap, make sure AutoSize is set to true, and then use the following code:

label1.Caption := 'Line one'+sLineBreak+'Line two';

Works in all versions of Delphi since sLineBreak was introduced, which I believe was Delphi 6.

回答2:

Here's an even shorter approach:

my_string := 'Hello,'#13#10' world!';

回答3:

my_string := 'Hello,' + #13#10 + 'world!';

#13#10 is the CR/LF characters in decimal

回答4:

On the side, a trick that can be useful:
If you hold your multiple strings in a TStrings, you just have to use the Text property of the TStrings like in the following example.

Label1.Caption := Memo1.Lines.Text;

And you'll get your multi-line label...

回答5:

Or you can use the ^M+^J shortcut also. All a matter of preference. the "CTRL-CHAR" codes are translated by the compiler.

MyString := 'Hello,' + ^M + ^J + 'world!';

You can take the + away between the ^M and ^J, but then you will get a warning by the compiler (but it will still compile fine).

回答6:

var
  stlst: TStringList;
begin
  Label1.Caption := 'Hello,'+sLineBreak+'world!';

  Label2.Caption := 'Hello,'#13#10'world!';

  Label3.Caption := 'Hello,' + chr(13) + chr(10) + 'world!';

  stlst := TStringList.Create;
  stlst.Add('Hello,');
  stlst.Add('world!');
  Label4.Caption := stlst.Text;

  Label5.WordWrap := True; //Multi-line Caption
  Label5.Caption := 'Hello,'^M^J'world!';

  Label6.Caption := AdjustLineBreaks('Hello,'#10'world!');
  {http://delphi.about.com/library/rtl/blrtlAdjustLineBreaks.htm}
end;

回答7:

The plattform agnostic way would be 'sLineBreak': http://www.freepascal.org/docs-html/rtl/system/slinebreak.html

Write('Hello' + sLineBreak + 'World!');

回答8:

ShowMessage('Hello'+Chr(10)+'World');

回答9:

I dont have a copy of Delphi to hand, but I'm fairly certain if you set the wordwrap property to true and the autosize property to false it should wrap any text you put it at the size you make the label. If you want to line break in a certain place then it might work if you set the above settings and paste from a text editor.

Hope this helps.

回答10:

Sometimes I don't want to clutter up my code space, especially for a static label. To just have it defined with the form, enter the label text on the form, then right click anywhere on the same form. Choose "View as Text". You will now see all of the objects as designed, but as text only. Scroll down or search for your text. When you find it, edit the caption, so it looks something like:

Caption = 'Line 1'#13'Line 2'#13'Line 3'

#13 means an ordinal 13, or ascii for carriage return. Chr(13) is the same idea, CHR() changes the number to an ordinal type.

Note that there are no semi-colon's in this particular facet of Delphi, and "=" is used rather than ":=". The text for each line is enclosed in single quotes.

Once you are done, right-click once again and choose "View as Form". You can now do any formatting such as bold, right justify, etc. You just can't re-edit the text on the form or you will lose your line breaks.

I also use "View as Text" for multiple changes where I just want to scroll through and do replacements, etc. Quick.

Dave

回答11:

 private
   { Private declarations }
   {declare a variable like this}
   NewLine : string; // ok
  // in next event handler assign a value to that variable (NewLine)
  // like the code down
procedure TMainForm.FormCreate(Sender: TObject);
begin`enter code here`
  NewLine := #10;
 {Next Code To show NewLine In action}
  //ShowMessage('Hello to programming with Delphi' + NewLine + 'Print New Lin now !!!!');
end;