var i: integer; s: String; IsStr: Boolean begin IsStr := False; for i:=1 to length(Edit1.text) do begin if not (S[i] in [80..89]) then IsStr:= True; end; if not IsStr then showmessage('是数字') end;
var I,code:integer;begin Val(Edit1.text,I,code); if code<>0 then ShowMessage('第'+IntToStr(Code)+'开始不是数字') else ShowMessage('是数字'); end;
var i: integer; s: String; IsStr: Boolean begin IsStr := False; for i:=1 to length(Edit1.text) do begin if not (ord(S[i]) in [80..89]) then IsStr:= True; end; if not IsStr then showmessage('是数字') end;
var s:float; try strtofloat(edit1.text) except showmessage('搞错拉'); end;
我觉得异常处理很不好,因为老是提示出错,我是在他的KEYPRESS 事件中 if ( not key in ['0'..'9',#42,#23] ) then key:=#0; 这样如果他输入的非法字符将视为无效输入
我的做法xugang96(漂泊在外,居无定所)差不多 但我的语句是这样写的:procedure TfrmMain.Edit1KeyPress(Sender: TObject; var Key: Char); begin if not (key in ['0'..'9']) then key:=#0; end;
duxbin()的少了backspace和del,总不能让人不能回退吧 procedure TfrmMain.Edit1KeyPress(Sender: TObject; var Key: Char); begin if not (key in ['0'..'9',#8,#83]) then key:=#0; end;
showmessage('数字')
else
showmessage('不是数字');
function IsNumber(s:string):boolean;
var tmp:integer;
begin
try
tmp:=StrToInt(s);
except
Result:=False;
exit;
end;
REsult:=true;
end;
i:=strToint(Edit3.Text );
showmessage('yes');
except
showmessage('no');
end;够绝吧~~!~~
i: integer;
s: String;
IsStr: Boolean
begin
IsStr := False;
for i:=1 to length(Edit1.text) do
begin
if not (S[i] in [80..89]) then
IsStr:= True;
end;
if not IsStr then
showmessage('是数字')
end;
I,code:integer;begin
Val(Edit1.text,I,code);
if code<>0 then
ShowMessage('第'+IntToStr(Code)+'开始不是数字')
else
ShowMessage('是数字');
end;
i: integer;
s: String;
IsStr: Boolean
begin
IsStr := False;
for i:=1 to length(Edit1.text) do
begin
if not (ord(S[i]) in [80..89]) then
IsStr:= True;
end;
if not IsStr then
showmessage('是数字')
end;
try
strtofloat(edit1.text)
except
showmessage('搞错拉');
end;
if ( not key in ['0'..'9',#42,#23] ) then
key:=#0;
这样如果他输入的非法字符将视为无效输入
但我的语句是这样写的:procedure TfrmMain.Edit1KeyPress(Sender: TObject; var Key: Char);
begin
if not (key in ['0'..'9']) then
key:=#0;
end;
procedure TfrmMain.Edit1KeyPress(Sender: TObject; var Key: Char);
begin
if not (key in ['0'..'9',#8,#83]) then
key:=#0;
end;