var
i: LongInt;
f: Double;
begin
if TryStrToInt(Edit1.Text,i) or TryStrToFloat(Edit1.Text, f) then
ShowMessage('是数字')
else
ShowMessage('不是数字');
end;
i: LongInt;
f: Double;
begin
if TryStrToInt(Edit1.Text,i) or TryStrToFloat(Edit1.Text, f) then
ShowMessage('是数字')
else
ShowMessage('不是数字');
end;
var
i, j: integer;
str: char;
begin
result := true;
Value := trim(Value);
j := Length(Value);
if j = 0 then
begin
result := false;
exit;
end;
for i := 1 to j do
begin
str := Value[i];
if not (str in ['0'..'9']) then
begin
result := false;
exit;
end;
end;
end; if IsDigital('123') then
ShowMessage('数字');
if IsDigital('a123') then
ShowMessage('数字');