procedure Tform1.Edit1KeyPress(Sender: TObject; var Key: Char); //控制edit1的輸入數字
var
p:Integer;
begin
//限制隻能輸入數字,小數點,負号
if not (Key in ['0'..'9', '.','-',#8, #13]) then
begin
Key := #0;
end;
//如果是小數,小數點前面隻能輸入一個零
if key = '0' then
begin
if (LeftStr(Edit1.Text,1) ='-') and (MidStr(Edit1.Text,2,1) = '0') and (Length(Edit1.Text) = 2) then
begin
Key:=#0;
end
//如果第一位是零,則零隻能輸入一次
else if (LeftStr(Edit1.Text,1) = '0') and (Length(Edit1.Text) = 1) then
begin
Key:=#0;
end
end
//限制隻能輸入一個小數點,且隻能在第二個位置開始
else if Key = '.' then
begin
if Edit1.SelStart = 0 then
Key := #0;
p := Pos('.', Edit1.Text);
if p > 0 then
Key := #0;
end
//限制隻能在第一個,且隻能輸入一個負号
else if Key = '-' then
begin
if Edit1.SelStart > 0 then
Key := #0;
p := Pos('-', Edit1.Text);
if p > 0 then Key := #0;
end;
end;