Delphi XE5 TIdUDPServer does not receive anything on Android

Question

I have a TIdUDPServer on a form setup with a default port and broadcast mode enabled and cannot get it to receive anything under Android.

The same code is working fine under iOS but if I retarget Android I do not receive anything.

Is there a trick I am missing. I have checked the "User Permissions" and turn on everything I think might influence this but have had no luck with getting it working.

Thanks in advance, Martin

Answer 1

Thank you Remy for putting me on the right track. Here is the complete code to receive broadcast UDP packets...

unit Androidapi.JNI.WiFiManager;

interface

uses
  Androidapi.JNIBridge, Androidapi.Jni,  androidapi.JNI.JavaTypes, androidapi.JNI.Net,
  androidapi.JNI.Os, FMX.Helpers.Android, Androidapi.JNI.GraphicsContentViewText, SysUtils;

Type
  JWiFiManager = interface;   // android/net/wifi/WifiManager
  JMulticastLock = interface; // android/net/wifi/WifiManager$MulticastLock

  JWiFiManagerClass = interface(JObjectClass)
   ['{F69F53AE-BC63-436A-8F69-57389B30CAA8}']
    function getSystemService(Contex: JString): JWiFiManager; cdecl;
  end;

  [JavaSignature('android/net/wifi/WifiManager')]
  JWiFiManager = interface(JObject)
  ['{382E85F2-6BF8-4255-BA3C-03C696AA6450}']
    function createMulticastLock(tag: JString): JMulticastLock;
  end;

  TJWiFiManager = class(TJavaGenericImport<JWiFiManagerClass, JWiFiManager>) end;

  JMulticastLockClass = interface(JObjectClass)
  ['{C0546633-3DF2-46B0-8E2C-C14411674A6F}']
  end;

  [JavaSignature('android/net/wifi/WifiManager$MulticastLock')]
  JMulticastLock = interface(JObject)
  ['{CFA00D0C-097C-45E3-8B33-0E5A6C9FB9F1}']
    procedure acquire();
    function isHeld(): Boolean;
    procedure release();
    procedure setReferenceCounted(refCounted: boolean);
  end;

  TJMulticastLock = class(TJavaGenericImport<JMulticastLockClass, JMulticastLock>) end;

  function GetWiFiManager: JWiFiManager;

implementation

function GetWiFiManager: JWiFiManager;
var
  Obj: JObject;
begin
  Obj := SharedActivityContext.getSystemService(TJContext.JavaClass.WIFI_SERVICE);
  if not Assigned(Obj) then
    raise Exception.Create('Could not locate Wifi Service');
  Result := TJWiFiManager.Wrap((Obj as ILocalObject).GetObjectID);
  if not Assigned(Result) then
    raise Exception.Create('Could not access Wifi Manager');
end;

And then to acquire the necessary lock...

wifi_manager := GetWiFiManager;
multiCastLock := wifi_manager.createMulticastLock(StringToJString('LightFactory Remote'));
multiCastLock.setReferenceCounted(true);
multiCastLock.acquire;

Finally dont forget the permissions mentioned in Remy's post.