循环看起来没问题，但看不到其他代码。



一个错误是文件名需要LPCSTR这是一个C风格的字符串，所以转换你需要的C ++字符串

the loop looks OK, but can't see other code.

one mistake is the filename needs LPCSTR which is a C style string so to convert the C++ string you'd need

str.c_str()

第二个错误是串联+使用字符串而不是C字符串。

所以一个想法是适应方法：

second mistake is concatenation with + works with string but not C strings.
so one idea is to adapt method:

string IntToStr(int n) 
{
    stringstream result;
    result<< "C://webcontent/QR"<<n<<".jpg";
    return result.str();
}

然后将字符串转换为

then convert string to

LPCSTR 

您的问题是关于构建LPCSTR。



尝试以下

Your question is really about constructing a LPCSTR.

Try the following

#include<string>
using namespace std;

for(int n = 0; n < 20; n++)
{
        string filename = "C://webcontent/QR"+ to_string((_ULonglong)n) +".jpg";
        eCode = BCSaveImageA(pBC, filename.c_str(), 4, LBarcodeWidth,LBarcodeHieght, dpi, dpi);
}

如果您的编译器符合C ++ 11标准，则不需要_ULonglong强制转换。

If your compiler is C++11 compliant you wont need the _ULonglong cast.