SetupDiGetDeviceInterfaceDetail 错误返回值为122

[yinwjvip_2012]

hardwareDeviceInfoSet是已经正确获得的值
deviceInterfaceData的值设置为
deviceInterfaceData.cbSize = sizeof(SP_DEVICE_INTERFACE_DATA);
//此处大小为32字节，系统是64位的win7

SetupDiEnumDeviceInterfaces (hardwareDeviceInfoSet, NULL, //infoData, &hidGUID, //interfaceClassGuid, deviceIndex, &deviceInterfaceData);
这个函数成功执行

SetupDiGetDeviceInterfaceDetail (hardwareDeviceInfoSet, &deviceInterfaceData, NULL, //interfaceDetail, 0, //interfaceDetailSize, &requiredSize, 0); //infoData))
这个函数失败返回值 为122，该怎么解决呀

[yinwjvip_2012]

是的，我看了参数，也看不出来有什么不对的地方，系统是64位的

[davidyu720]

122 : 传递给系统调用的数据区域太小。

[davidyu720]

返回122是正确的呀，此时requiredSize里面有正确的值。然后你分配requiredSize大小的buffer，再次调用SetupDiGetDeviceInterfaceDetail 即可。 http://msdn.microsoft.com/zh-cn/ff551120 Using this function to get details about an interface is typically a two-step process: 1.Get the required buffer size. Call SetupDiGetDeviceInterfaceDetail with a NULLDeviceInterfaceDetailData pointer, a DeviceInterfaceDetailDataSize of zero, and a valid RequiredSize variable. In response to such a call, this function returns the required buffer size at RequiredSize and fails with GetLastError returning ERROR_INSUFFICIENT_BUFFER. 2.Allocate an appropriately sized buffer and call the function again to get the interface details.