我的 char 数组使用 Visual Studios 2017 C++ 在 318 个字符处截断

Question

大家好我有一个问题，我的 char arrays (strings) 不会显示任何超过 318 characters 的内容。如果我执行 std::string 没问题并显示整个内容...但是如果我尝试使用 std::string.c_str() 将其转换为字符数组，它只会再次生成第一个 318 characters。任何帮助将不胜感激。我正在使用 Visual Studio 2017。实际字符串长度为517chars.

示例...

std::string x = "INSERT INTO oms.Customers (customerFirstName, CustomerMiddleInitial, customerLastName, customerPrefixSuffix, customerCompanyName, customerStreetReference, customerStreetAddress, customerCity, customerState, customerZip, CountryID, customerPhoneNumber, customerEmail, customerIsCompany, customerIsActive) Values('Bill', '
INSERT INTO oms.Customers(customerFirstName, CustomerMiddleInitial, customerLastName, customerPrefixSuffix, customerCompanyName, customerStreetReference, customerStreetAddress, customerCity, customerState, customerZip, CountryID, customerPhoneNumber, customerEmail, customerIsCompany, customerIsActive)Values('Bill', ' ', 'Cosby', '', 'The Cosby Show', 'Studio A', '1818 broadway st', 'Philadelphia', 'PA', '19809', '', '6169875942', 'Bill.Cosby@ididntdoit.com', '', ');SELECT SCOPE_IDENTITY() AS [SCOPE_IDENTITY];"

但是如果我制作任何类型的字符数组，就像我做的那样

char *y;
y= x.c_str

只有下面的会显示

INSERT INTO oms.Customers (customerFirstName, CustomerMiddleInitial, customerLastName, customerPrefixSuffix, customerCompanyName, customerStreetReference, customerStreetAddress, customerCity, customerState, customerZip, CountryID, customerPhoneNumber, customerEmail, customerIsCompany, customerIsActive) Values('Bill', '

如果我 strlen(y) 我得到 318。如果我这样做 x.length() 我得到 517.

如有任何帮助，我们将不胜感激。谢谢。

Answer 1

std::string 可能包含 '[=11=]' 个字符，这些字符将被 strlen(y).
识别为 C 风格 NUL 终止的字符串结束标记这就是 strlen() 和 std::string::length().

结果不同的原因

Answer 2

如果我将字符串设为原始字符串：

std::string x = R"(INSERT INTO oms.Customers (customerFirstName, CustomerMiddleInitial, customerLastName, customerPrefixSuffix, customerCompanyName, customerStreetReference,
        customerStreetAddress, customerCity, customerState, customerZip, CountryID, customerPhoneNumber, customerEmail, customerIsCompany, customerIsActive) Values('Bill',
        '

            INSERT INTO oms.Customers(customerFirstName, CustomerMiddleInitial, customerLastName, customerPrefixSuffix, customerCompanyName, customerStreetReference,
                customerStreetAddress, customerCity, customerState, customerZip, CountryID, customerPhoneNumber, customerEmail, customerIsCompany, customerIsActive)Values('Bill',
                    ' ', 'Cosby', '', 'The Cosby Show', 'Studio A', '1818 broadway st', 'Philadelphia', 'PA', '19809', '', '6169875942', 'Bill.Cosby@ididntdoit.com', '', ');SELECT
                    SCOPE_IDENTITY() AS[SCOPE_IDENTITY]; )";
                    char const *pStr = x.c_str();
                    _RPTA("strlen: %d\r\n", strlen(pStr));

长度打印为 857（_RPTA 是一个自定义宏，它打印到 VS 调试跟踪而不是像 printf 那样的程序控制台）。

我的 char 数组使用 Visual Studios 2017 C++ 在 318 个字符处截断

My char arrays cut off at 318 character using Visual Studios 2017 C++

c++

string

size

string-length

visual-studio-2017