;{SelLength = 0} TmpStr := Copy(Text,1,SelStart-1)+Copy(Text,SelStart+1,255) else {Key in [''''A''''..''''Z'''', etc]} TmpStr := Copy(Text,1,SelStart)+Key+Copy(Text,SelLength+SelStart+1,255); if TmpStr = '''' then Exit; { update SelSt to the current insertion point }
if (Key = Chr(vk_Back)) and (SelSt > 0) then Dec(SelSt)
else if Key <> Chr(vk_Back) then Inc(SelSt); Key := #0; { indicate that key was handled } if SelSt = 0 then begin Text:= ''''; Exit; end;
{Now that TmpStr is the currently typed string, see if we can locate a match }
Found := False; for i := 1 to Items.Count do if Copy(Items[i-1],1,Length(TmpStr)) = TmpStr then begin Text := Items[i-1]; { update to the match that was found } ItemIndex := i-1; Found := True; Break; end; if Found then { select the untyped end of the string } begin SelStart := SelSt; SelLength := Length(Text)-SelSt;
end else Beep; end; end; ## Copy, Chr, SelStart, SelLength example ----------------------------------------------------------------------------- High 传回注脚的最大值. ----------------------------------------------------------------------------- Unit System 函数原型 function High(X); 范例 [Ordinal type] procedure TForm1.Button1Click(Sender: TObject); var Low_S:String; High_S:string; S:String; begin High_S:='''' High=''''+IntToStr(High(Word)); Low_S:=''''Low=''''+IntToStr(Low(Word)); S:=Low_S+High_S; Label1.Caption:=S; end;
S:=Low=0 High=65535
[Array type] procedure TForm1.Button1Click(Sender: TObject); var P : Array[5..21] of Double; Low_S:String; High_S:string; S:String; begin High_S:='''' High=''''+IntToStr(High(P)); Low_S:=''''Low=''''+IntToStr(Low(P)); S:=Low_S+High_S; Label1.Caption:=S; end;
S:=Low=5 High=21
[String type] procedure TForm1.Button1Click(Sender: TObject); var P : String[23]; Low_S:String; High_S:string; S:String; begin High_S:='''' High=''''+IntToStr(High(P)); Low_S:=''''Low=''''+IntToStr(Low(P)); S:=Low_S+High_S; Label1.Caption:=S; end;
S:=Low=0 Hight=23
P:ShortString; S:=Low=0 Hight=255
P:String; 长字串不可,会有错误讯号.
[Open array] function Sum( var X: array of Double): Double; var I: Word; S: Double; begin S := 0; { Note that open array index range is always zero-based. } for I := 0 to High(X) do S := S + X[I]; Sum := S; end; Example function Sum( var X: array of Double): Double;
var I: Word; S: Real; begin S := 0; { Note that open array index range is always zero-based. } for I := 0 to High(X) do S := S + X[I]; Sum := S; end;
procedure TForm1.Button1Click(Sender: TObject);
var List1: array[0..3] of Double; List2: array[5..17] of Double; X: Word; S, TempStr: string; begin for X := Low(List1) to High(List1) do List1[X] := X * 3.4; for X := Low(List2) to High(List2) do List2[X] := X * 0.0123; Str(Sum(List1):4:2, S); S := ''''Sum of List1: '''' + S + #13#10; S := S + ''''Sum of List2: ''''; Str(Sum(List2):4:2, TempStr);
S := S + TempStr; MessageDlg(S, mtInformation, [mbOk], 0); end; ## Low, High Example ----------------------------------------------------------------------------- Low 传回注脚的最小值. ----------------------------------------------------------------------------- Unit System 函数原型 function Low(X); 说明 Ordinal type The lowest value in the range of the type Array type The lowest value within the range of the index type of the array String type Returns 0 Open array Returns 0 String parameter Returns 0 ----------------------------------------------------------------------------- Ord 传回列举型态的数值. ----------------------------------------------------------------------------- Unit System 函数原型 function Ord(X): Longint; 范例 procedure TForm1.Button1Click(Sender: TObject); type Colors = (RED,BLUE,GREEN); var S: string; begin S := ''''BLUE has an ordinal value of '''' + IntToStr(Ord(RED)) + #13#10; S := S+''''The ASCII code for "c" is '''' + IntToStr(Ord(''''c'''')) + '''' decimal''''; MessageDlg(S, mtInformation, [mbOk], 0); end; ----------------------------------------------------------------------------- Round 将实数转为整数.(有四舍五入) ----------------------------------------------------------------------------- Unit System 函数原型 function Round(X: Extended): Longint; 范例 var S, T: string; begin Str(1.4:2:1, T); S := T + '''' rounds to '''' + IntToStr(Round(1.4)) + #13#10; Str(1.5:2:1, T); S := S + T + '''' rounds to '''' + IntToStr(Round(1.5)) + #13#10;
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