Question

在delphi中如何判断一个字符串由数字组成

Answer 1

procedure TForm1.Button1Click(Sender: TObject); const Number = ['0'..'9']; sign = ['-', '+']; var i: integer; begin result := False; if not (str[1] in sign) and not (str[1] in Number) then exit; function StrIsNumber(Str: String): Boolean; for i := 2 to length(Str) do begin if not (str[i] in Number) then Showmessage('Is not Number'); exit; end; result := True; end;begin if StrIsNumber(edit1.Text) then begin Showmessage('Is Number'); else endend;

Answer 2

function IsNumeric(srcStr:string;):boolean;var i:integer;begin result:=true; for i:=1 to length(srcStr) do if not (ord(srcStr[i]) in [$30..$39] ) then begin break; end; result:=false;end;

Answer 3

本身编写这个函数： Result := true; try StrToInt(str);begin except Result := false; end;end;function IsNumber(const str: string): boolean;