Delphi 确实提供了一个名为FloatToDecimal转换浮点数（例如Extended) and Currency值转换为有用的结构以进行进一步格式化。例如。：
FloatToDecimal(..., 1234567890.1234, ...);
给你：
TFloatRec
Digits: array[0..20] of Char = "12345678901234"
Exponent: SmallInt = 10
IsNegative: Boolean = True
Where Exponent给出小数点左边的位数。
有一些特殊情况需要处理：
-
指数为零
Digits: array[0..20] of Char = "12345678901234"
Exponent: SmallInt = 0
IsNegative: Boolean = True
表示小数点左边没有数字，例如.12345678901234
-
指数为负数
Digits: array[0..20] of Char = "12345678901234"
Exponent: SmallInt = -3
IsNegative: Boolean = True
意味着您必须在小数点和第一位数字之间添加零，例如.00012345678901234
-
指数是-32768 (NaN，不是数字）
Digits: array[0..20] of Char = ""
Exponent: SmallInt = -32768
IsNegative: Boolean = False
表示该值不是数字，例如NAN
-
指数是32767 (INF, or -INF)
Digits: array[0..20] of Char = ""
Exponent: SmallInt = 32767
IsNegative: Boolean = False
表示该值为正无穷大或负无穷大（取决于IsNegative值），例如-INF
我们可以用FloatToDecimal作为创建与区域设置无关的字符串“的起点图片代码".
然后可以将该字符串传递给适当的 WindowsGetNumberFormat or GetCurrencyFormat函数来执行实际的正确定位。
我自己写的CurrToDecimalString and FloatToDecimalString它将数字转换为所需的独立于区域设置的格式：
class function TGlobalization.CurrToDecimalString(const Value: Currency): string;
var
digits: string;
s: string;
floatRec: TFloatRec;
begin
FloatToDecimal({var}floatRec, Value, fvCurrency, 0{ignored for currency types}, 9999);
//convert the array of char into an easy to access string
digits := PChar(Addr(floatRec.Digits[0]));
if floatRec.Exponent > 0 then
begin
//Check for positive or negative infinity (exponent = 32767)
if floatRec.Exponent = 32767 then //David Heffernan says that currency can never be infinity. Even though i can't test it, i can at least try to handle it
begin
if floatRec.Negative = False then
Result := 'INF'
else
Result := '-INF';
Exit;
end;
{
digits: 1234567 89
exponent--------^ 7=7 digits on left of decimal mark
}
s := Copy(digits, 1, floatRec.Exponent);
{
for the value 10000:
digits: "1"
exponent: 5
Add enough zero's to digits to pad it out to exponent digits
}
if Length(s) < floatRec.Exponent then
s := s+StringOfChar('0', floatRec.Exponent-Length(s));
if Length(digits) > floatRec.Exponent then
s := s+'.'+Copy(digits, floatRec.Exponent+1, 20);
end
else if floatRec.Exponent < 0 then
begin
//check for NaN (Exponent = -32768)
if floatRec.Exponent = -32768 then //David Heffernan says that currency can never be NotANumber. Even though i can't test it, i can at least try to handle it
begin
Result := 'NAN';
Exit;
end;
{
digits: .000123456789
^---------exponent
}
//Add zero, or more, "0"'s to the left
s := '0.'+StringOfChar('0', -floatRec.Exponent)+digits;
end
else
begin
{
Exponent is zero.
digits: .123456789
^
}
if length(digits) > 0 then
s := '0.'+digits
else
s := '0';
end;
if floatRec.Negative then
s := '-'+s;
Result := s;
end;
除了边缘情况NAN, INF and -INF，我现在可以将这些字符串传递给 Windows：
class function TGlobalization.GetCurrencyFormat(const DecimalString: WideString; const Locale: LCID): WideString;
var
cch: Integer;
ValueStr: WideString;
begin
Locale
LOCALE_INVARIANT
LOCALE_USER_DEFAULT <--- use this one (windows.pas)
LOCALE_SYSTEM_DEFAULT
LOCALE_CUSTOM_DEFAULT (Vista and later)
LOCALE_CUSTOM_UI_DEFAULT (Vista and later)
LOCALE_CUSTOM_UNSPECIFIED (Vista and later)
}
cch := Windows.GetCurrencyFormatW(Locale, 0, PWideChar(DecimalString), nil, nil, 0);
if cch = 0 then
RaiseLastWin32Error;
SetLength(ValueStr, cch);
cch := Windows.GetCurrencyFormatW(Locale, 0, PWideChar(DecimalString), nil, PWideChar(ValueStr), Length(ValueStr));
if (cch = 0) then
RaiseLastWin32Error;
SetLength(ValueStr, cch-1); //they include the null terminator /facepalm
Result := ValueStr;
end;
The FloatToDecimalString and GetNumberFormat实现留给读者作为练习（因为我实际上还没有编写浮点型，只是货币 - 我不知道如何处理指数表示法）。
还有鲍勃的叔叔； Delphi 下正确本地化的浮动和货币。
我已经完成了正确本地化整数、日期、时间和日期时间的工作。
Note：任何代码都会发布到公共领域。无需归属。
