c# - 带有前导零的 int.Parse()

Question

如何防止下面的代码抛出 FormatException。我希望能够将带有前导零的字符串解析为整数。有没有一种干净的方法可以做到这一点？

string value = "01";
int i = int.Parse(value);

Answer 1

您的代码为我运行，没有 FormatException(一旦您正确地使用了该方法):

string value = "01";
int i = int.Parse(value);

但这确实敲响了警钟；这是我多年前遇到的一个问题，Microsoft 将其视为针对 Windows(而非 .NET)本地化组件的错误。要测试您是否看到了这一点，请运行此代码并让我们知道您是否收到 FormatException:

string value = "0"; // just a zero
int i = int.Parse(value);

编辑:这是我 2007 年在 Usenet 上发的帖子。看看症状是否与您的相符。

For reference, here's what we found. The affected machine had bad data for the registry value [HKEY_CURRENT_USER\Control Panel \International\sPositiveSign]. Normally, this value is an empty REG_SZ (null-terminated string). In this case, the string was missing its terminator. This confused the API function GetLocaleInfoW(), causing it to think that '0' (ASCII number zero) was the positive sign for the current locale (it should normally be '+'). This caused all kinds of havoc.

You can verify this for yourself with regedit.exe: open that reg value by right-clicking on the value and selecting 'Modify Binary Data'. You should see two dots on the right (representing the null terminator). If you see no dots, you're affected. Fix it by adding a terminator (four zeros).

You can also check the value of CultureInfo.CurrentCulture.NumberFormat.PositiveSign; it should be '+'.

It's a bug in the Windows localization API, not the class libs. The reg value needs to be checked for a terminator. They're looking at it.

...和here's a report on Microsoft Connect关于这个问题: