WlanGetAvailableNetworkList contains maybe wrong amount of items (wlanapi.h)

[apo-d]

Description

Using the wlanapi.h method WlanGetAvailableNetworkList, i receive a WLAN_AVAILABLE_NETWORK_LIST with dwNumberOfItems > 1 (around 8), but when i try to access the availableNetworksList.Network[1] i get a Range error ("only valid value is 0: 1").

Steps to reproduce

• import package:win32/win32.dart
• call WlanOpenHandle to get the clientHandle
• call WlanEnumInterfaces to get the guid of the network interface
• call WlanGetAvailableNetworkList, get the WLAN_AVAILABLE_NETWORK_LIST struct, check the dwNumberOfItems and then iterate on the Networks array

Expected behavior

I can use a normal for-i loop until dwNumberOfItems - 1 and receive different WLAN_AVAILABLE_NETWORK items.

Environment

Windows 11, Dell computer

[halildurmus]

(Related to #399)

The reason you're getting a RangeError when accessing elements of the Network array in the WLAN_AVAILABLE_NETWORK_LIST is because the array is annotated with @Array(1):

win32/packages/win32/lib/src/structs.g.dart

Lines 10915 to 10916 in df8097c

	@Array(1)
	external Array<WLAN_AVAILABLE_NETWORK> Network;

This annotation tells the compiler that the array contains only a single element, which leads to an out-of-bounds error when trying to access subsequent elements.

This array is actually defined as a variable-length array in C, but Dart doesn't support variable-sized arrays yet. As a result, it's projected as a single-element array. This causes bounds-checking issues when you try to access any element beyond the first.

To access the full list of networks, you can get a pointer to the beginning of the array by calculating the memory address of the array and then iterating over it:

extension on Pointer<WLAN_AVAILABLE_NETWORK_LIST> {
  List<WLAN_AVAILABLE_NETWORK> get network {
    final networks = <WLAN_AVAILABLE_NETWORK>[];

    // Get a pointer to the beginning of the array.
    final ptr = Pointer<WLAN_AVAILABLE_NETWORK>.fromAddress(
      address +
      sizeOf<Uint32>() + // dwNumberOfItems
      sizeOf<Uint32>()   // dwIndex
    );

    // Iterate through the networks.
    for (var i = 0; i < ref.dwNumberOfItems; i++) {
      final network = (ptr + i).ref;
      networks.add(network);
    }

    return networks;
  }
}

You can call this extension method from a pointer to the WLAN_AVAILABLE_NETWORK_LIST struct returned by the WlanGetAvailableNetworkList function. Please let me know if this works.