winapi - 为什么WNetOpenEnum会得到ERROR_INVALID_ADDRESS(487)结果？

Question

试图在Rust上使用WINAPI库https://docs.microsoft.com/en-us/windows/win32/wnet/enumerating-network-resources重写

let dw_result: DWORD;
let mut h_enum: LPHANDLE = null_mut();
let mut lpnr_local: LPNETRESOURCEW = null_mut();


dw_result = WNetOpenEnumW(RESOURCE_GLOBALNET, // all network resources
                          RESOURCETYPE_ANY,   // all resources
                          0,  // enumerate all resources
                          lpnr_local,       // NULL first time the function is called
                          h_enum);
if dw_result != WN_NO_ERROR {
     println!("WnetOpenEnum failed with error {:?}\n", dw_result);
}

但是此代码将487分配给dw_result，这意味着ERROR_INVALID_ADDRESS
而且我不明白什么是错的

Answer 1

我猜您怀疑LPHANDLE和HANDLE之间的区别。

LP stands for Long Pointer. It's a pointer to a handle.

如果要使用 LPHANDLE，请给它一个合法地址。
像这样:(C++)

HANDLE ph;
LPHANDLE hEnum = &ph;

或者只是使用 HANDLE。

let mut h_enum: HANDLE;
...
dw_result = WNetOpenEnumW(RESOURCE_GLOBALNET, // all network resources
                      RESOURCETYPE_ANY,   // all resources
                      0,  // enumerate all resources
                      lpnr_local,       // NULL first time the function is called
                      &h_enum);

相关: LPHANDLE vs. HANDLE