function IsDigit(key: char): boolean; begin if key in [0..9] then Result := true; end;
典型应用: edit1 的onKeyPress事件里面:... if IsDigit then .... ...
一个简单的方法:在FORM上放一个EDIT1,一个BUTTON1 procedure TForm1.Button1Click(Sender: TObject); var i:integer; begin try i:=strtoint(edit1.Text); showmessage('你输入的是数字 :'+inttostr(i)); except showmessage('你输入的是字符(串) :'+edit1.Text); end; end;
procedure TForm1.Edit1KeyUp(Sender: TObject; var Key: Word; Shift: TShiftState); begin if key in [$41..$5A] then begin edit1.text:=inttostr(strtoint('$'+edit1.text)); end; 照着这个自己写一个吧
if not (Key in ['0'..'9', #8,#9,#13]) then Key := #0;
procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char); begin if not (Key in ['0'..'9']) then showmessage('不是数字'); end;
begin
if key in [0..9] then
Result := true;
end;
edit1 的onKeyPress事件里面:...
if IsDigit then
....
...
procedure TForm1.Button1Click(Sender: TObject);
var i:integer;
begin
try
i:=strtoint(edit1.Text);
showmessage('你输入的是数字 :'+inttostr(i));
except
showmessage('你输入的是字符(串) :'+edit1.Text);
end;
end;
Shift: TShiftState);
begin
if key in [$41..$5A] then
begin
edit1.text:=inttostr(strtoint('$'+edit1.text));
end;
照着这个自己写一个吧
begin
if not (Key in ['0'..'9']) then
showmessage('不是数字');
end;
procedure TForm1.EDIT1EXIT(Sender: TObject);
begin
try
strtoint(edit1.Text);
except
showmessage('不是一个有效的数字,请重新输入');
end;
end;
begin
if trystrtoint(edit1.text,i) then showmessage('it is integer');
end
try
strtoint(edit1.Text);
except
showmessage("不是数字!");
end;