RegQueryValueEx函数返回234错误解决方法

最新推荐文章于 2025-08-12 15:03:52 发布

原创最新推荐文章于 2025-08-12 15:03:52 发布 · 869 阅读

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文章标签：

#buffer #performance #数据库服务器 #function #null #数据库

本文详细介绍了在使用RegQueryValueEx函数读取注册表数据时遇到234错误的常见原因及解决方案。通过实例演示了如何确保缓冲区大小足够以避免错误，并提供了代码示例来帮助开发者正确处理这种情况。

我们在调用RegQueryValueEx这个函数，在注册表中读取字符串形式的数据时候，经常会出现返回234错误。
MSDN说是　If the buffer specified by lpData parameter is not large enough to hold the data, the function returns the value ERROR_MORE_DATA,
Window NT: If hKey specifies HKEY_PERFORMANCE_DATA and the lpData buffer is too small, RegQueryValueEx returns ERROR_MORE_DATA but lpcbData does not return the required buffer size. This is because the size of the performance data can change from one call to the next. In this case, you must increase the buffer size and call RegQueryValueEx again passing the updated buffer size in the lpcbData parameter. Repeat this until the function succeeds. You need to maintain a separate variable to keep track of the buffer size, because the value returned by lpcbData is unpredictable.
解决方法如下：
BYTE byBuffer[1024];
DWORD dwLen = 1024;
// 读取数据库密码
RegQueryValueEx(m_hKey, "DBPassword", NULL, &dwType, byBuffer, &dwLen);
m_pt.strPwd = (LPCTSTR)byBuffer;

// 读取数据库服务器地址
dwLen = 1024;
RegQueryValueEx(m_hKey, "DBServerAddress", NULL, &dwType, byBuffer, &dwLen);
m_pt.strHostName = (LPCTSTR)byBuffer;

// 读取数据库用户名
dwLen = 1024;
RegQueryValueEx(m_hKey, "DBUser", NULL, &dwType, byBuffer, &dwLen);
m_pt.strDBUser = (LPCTSTR)byBuffer;