Xamarin.Mac使SIGSEGV模糊

Question

我在xamarin.mac遇到了晦涩的段xamarin.mac ，这是（无用的）stacktrace：

  at <unknown> <0xffffffff>
  at (wrapper managed-to-native) MonoMac.AppKit.NSApplication.NSApplicationMain     (int,string[]) <0xffffffff>
  at MonoMac.AppKit.NSApplication.Main (string[]) <0x00097>
  at gitbookpro.mac.MainClass.Main (string[]) <0x00017>
  at (wrapper runtime-invoke) <Module>.runtime_invoke_void_object (object,intptr,intptr,intptr) <0xffffffff>

在处理NSOutlineView上的SelectionDidChange之后，会发生崩溃，该处理会进行大量处理。

很难确定到底是什么导致了崩溃。

有任何想法吗 ？

Answer 1

该错误是由于C#对象被错误地垃圾回收引起的 。

之所以将它们作为垃圾回收是因为这些对象将返回到objective-c代码（本机代码），并且由于C#没有保留引用，因此垃圾回收器正在删除它们。

这就是正在发生的事情：

1. create C# obj 2. return obj to native code 3. ... wait a little bit ... 4. turn native object back into to C# obj (in event handlers etc ...) 5. Access C# obj <= This would fail occasionally since it was being garbage collected during step #3

您应该做什么：

1. create C# obj 1bis. Keep an extra reference to the object somewhere (in an Dictionary for example) 2. return obj to native code 3. ... wait a little bit ... 4. turn native object back into to C# obj (in event handlers etc ...) 4bis. Remove extra reference 5. Access C# obj <= This would fail occasionally since it was being garbage collected during step #3

就是这样！