MobileLocation crashes without network

Herman_Dubach · June 17, 2022, 10:55am

If there is no access to the web MobileLocation crashes. How can I first check if there is a connection?

Jason_King · June 17, 2022, 11:38am

You can use the Reachability class in iOSKit:

kingj5/iOSKit/blob/master/Modules/Extensions/Reachability.xojo_code

#tag Class
Protected Class Reachability
	#tag Method, Flags = &h0
		Sub Constructor()
		  declare function SCNetworkReachabilityCreateWithName lib "SystemConfiguration" (allocator as ptr, str as CString) as ptr
		  dim t as Text = "captive.apple.com"
		  dim ReachabilityRef as Ptr = SCNetworkReachabilityCreateWithName(Nil, t.ToCString(xojo.Core.TextEncoding.UTF8))
		  
		  dim reachableFlags as UInt32
		  declare function SCNetworkReachabilityGetFlags lib "SystemConfiguration" (target as ptr, byref flags as UInt32) as Boolean
		  dim success as Boolean = SCNetworkReachabilityGetFlags(ReachabilityRef, reachableFlags)
		  if success then
		    ParseFlags(reachableFlags)
		  end if
		  Declare Sub CFRelease Lib "CoreFoundation" ( CFTypeRef As Ptr )
		  CFRelease( ReachabilityRef )
		End Sub
	#tag EndMethod

	#tag Method, Flags = &h21

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Herman_Dubach · June 19, 2022, 2:28pm

Hi Jason, thanks for your reaction.

I implemented this, but success is always true. I don’t doubt I do something wrong…

declare function SCNetworkReachabilityCreateWithName lib “SystemConfiguration” (allocator as ptr, str as CString) as ptr
dim t as Text = “captive.apple.com”
dim ReachabilityRef as Ptr = SCNetworkReachabilityCreateWithName(Nil, t.ToCString(xojo.Core.TextEncoding.UTF8))

dim reachableFlags as UInt32
declare function SCNetworkReachabilityGetFlags lib “SystemConfiguration” (target as ptr, byref flags as UInt32) as Boolean
dim success as Boolean = SCNetworkReachabilityGetFlags(ReachabilityRef, reachableFlags)
if success then
MessageBox “yes”
else
messageBox “no”
end if

return success

Jason_Tait · June 19, 2022, 10:12pm

It would help to know at what point you get the crash and whether you can an exception and what that is?

I have an app that uses MobileLocation and it doesn’t crash with no internet. Are you checking the AuthorizationState property before calling Start?

Herman_Dubach · July 7, 2022, 10:17am

Hi Jason, I was not able to react for some time. Sorry.

It is not MobileLocation, but MapView that causes the crash.
If I enable the Flight mode to have no access to the web the app crashes.
So I tried your suggestion, see above. But the result is always TRUE.

Herman_Dubach · July 13, 2022, 1:29pm

Solved with Reachability!
Thanks