我写了一个PDF阅读器。它一次呈现一页。使用轻扫手势，用户可以切换到下一页。如果我继续快速切换页面（真的，非常快），我会得到以下错误。我尝试调试我在Monotouch中没有异常。 有人可以从堆栈跟踪中读取合理的信息吗？
Stacktrace:
at (wrapper managed-to-native) MonoTouch.UIKit.UIApplication.UIApplicationMain (int,string[],intptr,intptr) <0x00004>
at (wrapper managed-to-native) MonoTouch.UIKit.UIApplication.UIApplicationMain (int,string[],intptr,intptr) <0x00004>
at MonoTouch.UIKit.UIApplication.Main (string[],string,string) [0x00038] in /Users/plasma/Source/iphone-3/monotouch/UIKit/UIApplication.cs:26
at MonoTouch.UIKit.UIApplication.Main (string[]) [0x00000] in /Users/plasma/Source/iphone-3/monotouch/UIKit/UIApplication.cs:31
at testBrowser.Application.Main (string[]) [0x00000] in /Users/itest/Documents/Develop/testBrowser/testBrowser/Main.cs:14
at (wrapper runtime-invoke) <Module>.runtime_invoke_void_object (object,intptr,intptr,intptr) <IL 0x0001d, 0x00043>
Native stacktrace:
0 testBrowser 0x000be9db mono_handle_native_sigsegv + 343
1 testBrowser 0x0000e7a6 mono_sigsegv_signal_handler + 313
2 libSystem.B.dylib 0x9118c46b _sigtramp + 43
3 ??? 0xffffffff 0x0 + 4294967295
4 QuartzCore 0x03035232 CABackingStoreCopyRenderImage + 64
5 QuartzCore 0x03035060 _ZN2CA6Render17copy_render_valueEPKvPFP12CGColorSpacevE + 212
6 QuartzCore 0x0303326d -[CALayer(CALayerPrivate) _copyRenderLayer:layerFlags:commitFlags:] + 434
7 QuartzCore 0x030330b4 CALayerCopyRenderLayer + 55
8 QuartzCore 0x030311d2 _ZN2CA7Context12commit_layerEP8_CALayerjjPv + 122
9 QuartzCore 0x030310e1 CALayerCommitIfNeeded + 323
10 QuartzCore 0x03031069 CALayerCommitIfNeeded + 203
11 QuartzCore 0x03031069 CALayerCommitIfNeeded + 203
12 QuartzCore 0x0301f7b9 _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 1395
13 QuartzCore 0x0301f0d0 _ZN2CA11Transaction6commitEv + 292
14 QuartzCore 0x0304f7d5 _ZN2CA11Transaction17observer_callbackEP19__CFRunLoopObservermPv + 99
15 CoreFoundation 0x00dfafbb __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 27
16 CoreFoundation 0x00d900e7 __CFRunLoopDoObservers + 295
17 CoreFoundation 0x00d58bd7 __CFRunLoopRun + 1575
18 CoreFoundation 0x00d58240 CFRunLoopRunSpecific + 208
19 CoreFoundation 0x00d58161 CFRunLoopRunInMode + 97
20 GraphicsServices 0x03eb8268 GSEventRunModal + 217
21 GraphicsServices 0x03eb832d GSEventRun + 115
22 UIKit 0x01bf242e UIApplicationMain + 1160
23 ??? 0x09d31c41 0x0 + 164830273
24 ??? 0x09d31b7a 0x0 + 164830074
25 ??? 0x09d3157d 0x0 + 164828541
26 ??? 0x09d314b9 0x0 + 164828345
27 ??? 0x09d31514 0x0 + 164828436
28 testBrowser 0x0000e56a mono_jit_runtime_invoke + 1360
29 testBrowser 0x001c961b mono_runtime_invoke + 137
30 testBrowser 0x001cb2d7 mono_runtime_exec_main + 714
31 testBrowser 0x001cabfd mono_runtime_run_main + 812
32 testBrowser 0x00095354 mono_jit_exec + 200
33 testBrowser 0x0027d299 main + 3494
34 testBrowser 0x00003009 _start + 208
35 testBrowser 0x00002f38 start + 40
Debug info from gdb:
warning: .o file "/Developer/MonoTouch/SDKs/MonoTouch.iphonesimulator.sdk/usr/lib/libmonotouch.a(monotouch-glue.x86.o)" more recent than executable timestamp in "/Users/itest/Library/Application Support/iPhone Simulator/4.2/Applications/08D29A1D-AB54-49CC-9C55-FE763BB6BC37/testBrowser.app/testBrowser"
warning: Could not open OSO file /Developer/MonoTouch/SDKs/MonoTouch.iphonesimulator.sdk/usr/lib/libmonotouch.a(monotouch-glue.x86.o) to scan for pubtypes for objfile /Users/itest/Library/Application Support/iPhone Simulator/4.2/Applications/08D29A1D-AB54-49CC-9C55-FE763BB6BC37/testBrowser.app/testBrowser
warning: .o file "/Developer/MonoTouch/SDKs/MonoTouch.iphonesimulator.sdk/usr/lib/libmonotouch.a(monotouch-x86.double-abi-stret-trampoline.o)" more recent than executable timestamp in "/Users/itest/Library/Application Support/iPhone Simulator/4.2/Applications/08D29A1D-AB54-49CC-9C55-FE763BB6BC37/testBrowser.app/testBrowser"
warning: Could not open OSO file /Developer/MonoTouch/SDKs/MonoTouch.iphonesimulator.sdk/usr/lib/libmonotouch.a(monotouch-x86.double-abi-stret-trampoline.o) to scan for pubtypes for objfile /Users/itest/Library/Application Support/iPhone Simulator/4.2/Applications/08D29A1D-AB54-49CC-9C55-FE763BB6BC37/testBrowser.app/testBrowser
warning: .o file "/Developer/MonoTouch/SDKs/MonoTouch.iphonesimulator.sdk/usr/lib/libmonotouch.a(gc.x86.o)" more recent than executable timestamp in "/Users/itest/Library/Application Support/iPhone Simulator/4.2/Applications/08D29A1D-AB54-49CC-9C55-FE763BB6BC37/testBrowser.app/testBrowser"
warning: Could not open OSO file /Developer/MonoTouch/SDKs/MonoTouch.iphonesimulator.sdk/usr/lib/libmonotouch.a(gc.x86.o) to scan for pubtypes for objfile /Users/itest/Library/Application Support/iPhone Simulator/4.2/Applications/08D29A1D-AB54-49CC-9C55-FE763BB6BC37/testBrowser.app/testBrowser
warning: .o file "/Developer/MonoTouch/SDKs/MonoTouch.iphonesimulator.sdk/usr/lib/libmonotouch.a(zlib-helper.x86.o)" more recent than executable timestamp in "/Users/itest/Library/Application Support/iPhone Simulator/4.2/Applications/08D29A1D-AB54-49CC-9C55-FE763BB6BC37/testBrowser.app/testBrowser"
warning: Could not open OSO file /Developer/MonoTouch/SDKs/MonoTouch.iphonesimulator.sdk/usr/lib/libmonotouch.a(zlib-helper.x86.o) to scan for pubtypes for objfile /Users/itest/Library/Application Support/iPhone Simulator/4.2/Applications/08D29A1D-AB54-49CC-9C55-FE763BB6BC37/testBrowser.app/testBrowser
warning: Could not find object file "/var/folders/Ny/NyElTwhDGD8kZMqIEeLGXE+++TI/-Tmp-//ccvRqNHg.o" - no debug information available for "template.m".
warning: .o file "/Developer/usr/lib/gcc/i686-apple-darwin10/4.2.1/libgcc.a(_divdi3.o)" more recent than executable timestamp in "/Users/itest/Library/Application Support/iPhone Simulator/4.2/Applications/08D29A1D-AB54-49CC-9C55-FE763BB6BC37/testBrowser.app/testBrowser"
warning: Could not open OSO file /Developer/usr/lib/gcc/i686-apple-darwin10/4.2.1/libgcc.a(_divdi3.o) to scan for pubtypes for objfile /Users/itest/Library/Application Support/iPhone Simulator/4.2/Applications/08D29A1D-AB54-49CC-9C55-FE763BB6BC37/testBrowser.app/testBrowser
warning: .o file "/Developer/usr/lib/gcc/i686-apple-darwin10/4.2.1/libgcc.a(_moddi3.o)" more recent than executable timestamp in "/Users/itest/Library/Application Support/iPhone Simulator/4.2/Applications/08D29A1D-AB54-49CC-9C55-FE763BB6BC37/testBrowser.app/testBrowser"
warning: Could not open OSO file /Developer/usr/lib/gcc/i686-apple-darwin10/4.2.1/libgcc.a(_moddi3.o) to scan for pubtypes for objfile /Users/itest/Library/Application Support/iPhone Simulator/4.2/Applications/08D29A1D-AB54-49CC-9C55-FE763BB6BC37/testBrowser.app/testBrowser
warning: .o file "/Developer/usr/lib/gcc/i686-apple-darwin10/4.2.1/libgcc.a(_udivdi3.o)" more recent than executable timestamp in "/Users/itest/Library/Application Support/iPhone Simulator/4.2/Applications/08D29A1D-AB54-49CC-9C55-FE763BB6BC37/testBrowser.app/testBrowser"
warning: Could not open OSO file /Developer/usr/lib/gcc/i686-apple-darwin10/4.2.1/libgcc.a(_udivdi3.o) to scan for pubtypes for objfile /Users/itest/Library/Application Support/iPhone Simulator/4.2/Applications/08D29A1D-AB54-49CC-9C55-FE763BB6BC37/testBrowser.app/testBrowser
warning: .o file "/Developer/usr/lib/gcc/i686-apple-darwin10/4.2.1/libgcc.a(_umoddi3.o)" more recent than executable timestamp in "/Users/itest/Library/Application Support/iPhone Simulator/4.2/Applications/08D29A1D-AB54-49CC-9C55-FE763BB6BC37/testBrowser.app/testBrowser"
warning: Could not open OSO file /Developer/usr/lib/gcc/i686-apple-darwin10/4.2.1/libgcc.a(_umoddi3.o) to scan for pubtypes for objfile /Users/itest/Library/Application Support/iPhone Simulator/4.2/Applications/08D29A1D-AB54-49CC-9C55-FE763BB6BC37/testBrowser.app/testBrowser
warning: .o file "/Developer/MonoTouch/SDKs/MonoTouch.iphonesimulator.sdk/usr/lib/libmonotouch.a(monotouch-glue.x86.o)" more recent than executable timestamp in "/Users/itest/Library/Application Support/iPhone Simulator/4.2/Applications/08D29A1D-AB54-49CC-9C55-FE763BB6BC37/testBrowser.app/testBrowser"
warning: Couldn't open object file '/Developer/MonoTouch/SDKs/MonoTouch.iphonesimulator.sdk/usr/lib/libmonotouch.a(monotouch-glue.x86.o)'
Attaching to process 17837.
Reading symbols for shared libraries . done
Reading symbols for shared libraries ........................................................................................................................... done
0x91131459 in read$UNIX2003 ()
15 0x9114ba12 in __workq_kernreturn ()
14 0x9114ba12 in __workq_kernreturn ()
13 0x911540a6 in __semwait_signal ()
12 "com.apple.CFSocket.private" 0x911450c6 in select$DARWIN_EXTSN ()
11 0x911260fa in mach_msg_trap ()
10 0x911540a6 in __semwait_signal ()
9 0x911540a6 in __semwait_signal ()
8 0x911b9a7e in poll$UNIX2003 ()
7 0x911540a6 in __semwait_signal ()
6 "WebThread" 0x911260fa in mach_msg_trap ()
5 0x911540a6 in __semwait_signal ()
4 0x91126136 in semaphore_wait_trap ()
3 0x911260fa in mach_msg_trap ()
2 "com.apple.libdispatch-manager" 0x9114c982 in kevent ()
* 1 "com.apple.main-thread" 0x91131459 in read$UNIX2003 ()
Thread 15 (process 17837):
#0 0x9114ba12 in __workq_kernreturn ()
#1 0x9114bfa8 in _pthread_wqthread ()
#2 0x9114bbc6 in start_wqthread ()
Thread 14 (process 17837):
#0 0x9114ba12 in __workq_kernreturn ()
#1 0x9114bfa8 in _pthread_wqthread ()
#2 0x9114bbc6 in start_wqthread ()
Thread 13 (process 17837):
#0 0x911540a6 in __semwait_signal ()
#1 0x91153d62 in _pthread_cond_wait ()
#2 0x911559f8 in pthread_cond_wait$UNIX2003 ()
#3 0x0022d0bc in _wapi_handle_timedwait_signal_handle (handle=0x101, timeout=0x0, alertable=1, poll=0) at ../../../../mono/io-layer/handles.c:1614
#4 0x0022ce70 in _wapi_handle_wait_signal_handle (handle=0x101, alertable=1) at ../../../../mono/io-layer/handles.c:1557
#5 0x00242a6e in WaitForSingleObjectEx (handle=0x101, timeout=4294967295, alertable=1) at ../../../../mono/io-layer/wait.c:205
#6 0x00201f39 in async_invoke_thread (data=0x0) at ../../../../mono/metadata/threadpool.c:1485
#7 0x00203836 in start_wrapper (data=0xda7eaa0) at ../../../../mono/metadata/threads.c:661
#8 0x00244c76 in thread_start_routine (args=0x706c680) at ../../../../mono/io-layer/wthreads.c:286
#9 0x002746eb in GC_start_routine (arg=0xa20aea0) at ../../../libgc/pthread_support.c:1390
#10 0x9115385d in _pthread_start ()
#11 0x911536e2 in thread_start ()
Thread 12 (process 17837):
#0 0x911450c6 in select$DARWIN_EXTSN ()
#1 0x00d8ccbc in __CFSocketManager ()
#2 0x9115385d in _pthread_start ()
#3 0x911536e2 in thread_start ()
Thread 11 (process 17837):
#0 0x911260fa in mach_msg_trap ()
#1 0x91126867 in mach_msg ()
#2 0x00dfb4a6 in __CFRunLoopServiceMachPort ()
#3 0x00d58874 in __CFRunLoopRun ()
#4 0x00d58240 in CFRunLoopRunSpecific ()
#5 0x00d58161 in CFRunLoopRunInMode ()
#6 0x01378162 in +[NSURLConnection(NSURLConnectionReallyInternal) _resourceLoadLoop:] ()
#7 0x01342d4c in -[NSThread main] ()
#8 0x01342cd8 in __NSThread__main__ ()
#9 0x9115385d in _pthread_start ()
#10 0x911536e2 in thread_start ()
Thread 10 (process 17837):
#0 0x911540a6 in __semwait_signal ()
#1 0x91153d62 in _pthread_cond_wait ()
#2 0x911559f8 in pthread_cond_wait$UNIX2003 ()
#3 0x0022d0bc in _wapi_handle_timedwait_signal_handle (handle=0x10f, timeout=0x0, alertable=1, poll=0) at ../../../../mono/io-layer/handles.c:1614
#4 0x0022ce70 in _wapi_handle_wait_signal_handle (handle=0x10f, alertable=1) at ../../../../mono/io-layer/handles.c:1557
#5 0x00242a6e in WaitForSingleObjectEx (handle=0x10f, timeout=4294967295, alertable=1) at ../../../../mono/io-layer/wait.c:205
#6 0x001fee14 in async_invoke_io_thread (data=0x0) at ../../../../mono/metadata/threadpool.c:369
#7 0x00203836 in start_wrapper (data=0xda38170) at ../../../../mono/metadata/threads.c:661
#8 0x00244c76 in thread_start_routine (args=0x706c604) at ../../../../mono/io-layer/wthreads.c:286
#9 0x002746eb in GC_start_routine (arg=0xa20aea0) at ../../../libgc/pthread_support.c:1390
#10 0x9115385d in _pthread_start ()
#11 0x911536e2 in thread_start ()
Thread 9 (process 17837):
#0 0x911540a6 in __semwait_signal ()
#1 0x91153d62 in _pthread_cond_wait ()
#2 0x911559f8 in pthread_cond_wait$UNIX2003 ()
#3 0x0022d0bc in _wapi_handle_timedwait_signal_handle (handle=0x10f, timeout=0x0, alertable=1, poll=0) at ../../../../mono/io-layer/handles.c:1614
#4 0x0022ce70 in _wapi_handle_wait_signal_handle (handle=0x10f, alertable=1) at ../../../../mono/io-layer/handles.c:1557
#5 0x00242a6e in WaitForSingleObjectEx (handle=0x10f, timeout=4294967295, alertable=1) at ../../../../mono/io-layer/wait.c:205
#6 0x001fee14 in async_invoke_io_thread (data=0x0) at ../../../../mono/metadata/threadpool.c:369
#7 0x00203836 in start_wrapper (data=0xd9305b0) at ../../../../mono/metadata/threads.c:661
#8 0x00244c76 in thread_start_routine (args=0x706c490) at ../../../../mono/io-layer/wthreads.c:286
#9 0x002746eb in GC_start_routine (arg=0xa20af60) at ../../../libgc/pthread_support.c:1390
#10 0x9115385d in _pthread_start ()
#11 0x911536e2 in thread_start ()
Thread 8 (process 17837):
#0 0x911b9a7e in poll$UNIX2003 ()
#1 0x00250781 in mono_poll (ufds=0x716c000, nfds=2, timeout=-1) at ../../../../mono/utils/mono-poll.c:8
#2 0x001ff1cd in socket_io_poll_main (p=0x35db20) at ../../../../mono/metadata/threadpool.c:495
#3 0x00203836 in start_wrapper (data=0xd9305b0) at ../../../../mono/metadata/threads.c:661
#4 0x00244c76 in thread_start_routine (args=0x706c414) at ../../../../mono/io-layer/wthreads.c:286
#5 0x002746eb in GC_start_routine (arg=0xa20af60) at ../../../libgc/pthread_support.c:1390
#6 0x9115385d in _pthread_start ()
#7 0x911536e2 in thread_start ()
Thread 7 (process 17837):
#0 0x911540a6 in __semwait_signal ()
#1 0x91153d62 in _pthread_cond_wait ()
#2 0x911559f8 in pthread_cond_wait$UNIX2003 ()
#3 0x0022d0bc in _wapi_handle_timedwait_signal_handle (handle=0x101, timeout=0x0, alertable=1, poll=0) at ../../../../mono/io-layer/handles.c:1614
#4 0x0022ce70 in _wapi_handle_wait_signal_handle (handle=0x101, alertable=1) at ../../../../mono/io-layer/handles.c:1557
#5 0x00242a6e in WaitForSingleObjectEx (handle=0x101, timeout=4294967295, alertable=1) at ../../../../mono/io-layer/wait.c:205
#6 0x00201f39 in async_invoke_thread (data=0x0) at ../../../../mono/metadata/threadpool.c:1485
#7 0x00203836 in start_wrapper (data=0xd917340) at ../../../../mono/metadata/threads.c:661
#8 0x00244c76 in thread_start_routine (args=0x706c2a0) at ../../../../mono/io-layer/wthreads.c:286
#9 0x002746eb in GC_start_routine (arg=0xa20af60) at ../../../libgc/pthread_support.c:1390
#10 0x9115385d in _pthread_start ()
#11 0x911536e2 in thread_start ()
Thread 6 (process 17837):
#0 0x911260fa in mach_msg_trap ()
#1 0x91126867 in mach_msg ()
#2 0x00dfb4a6 in __CFRunLoopServiceMachPort ()
#3 0x00d58874 in __CFRunLoopRun ()
#4 0x00d58240 in CFRunLoopRunSpecific ()
#5 0x00d58161 in CFRunLoopRunInMode ()
#6 0x04f7e423 in RunWebThread ()
#7 0x9115385d in _pthread_start ()
#8 0x911536e2 in thread_start ()
Thread 5 (process 17837):
#0 0x911540a6 in __semwait_signal ()
#1 0x9117fee5 in nanosleep$UNIX2003 ()
#2 0x9117fe23 in usleep$UNIX2003 ()
#3 0x002774e0 in monotouch_pump_gc ()
#4 0x9115385d in _pthread_start ()
#5 0x911536e2 in thread_start ()
Thread 4 (process 17837):
#0 0x91126136 in semaphore_wait_trap ()
#1 0x0015b189 in finalizer_thread (unused=0x0) at ../../../../mono/metadata/gc.c:1026
#2 0x00203836 in start_wrapper (data=0x6e33210) at ../../../../mono/metadata/threads.c:661
#3 0x00244c76 in thread_start_routine (args=0x706c034) at ../../../../mono/io-layer/wthreads.c:286
#4 0x002746eb in GC_start_routine (arg=0x6ff8f60) at ../../../libgc/pthread_support.c:1390
#5 0x9115385d in _pthread_start ()
#6 0x911536e2 in thread_start ()
Thread 3 (process 17837):
#0 0x911260fa in mach_msg_trap ()
#1 0x91126867 in mach_msg ()
#2 0x0011cfb2 in mach_exception_thread (arg=0x0) at ../../../../mono/mini/mini-darwin.c:138
#3 0x9115385d in _pthread_start ()
#4 0x911536e2 in thread_start ()
Thread 2 (process 17837):
#0 0x9114c982 in kevent ()
#1 0x9114d09c in _dispatch_mgr_invoke ()
#2 0x9114c559 in _dispatch_queue_invoke ()
#3 0x9114c2fe in _dispatch_worker_thread2 ()
#4 0x9114bd81 in _pthread_wqthread ()
#5 0x9114bbc6 in start_wqthread ()
Thread 1 (process 17837):
#0 0x91131459 in read$UNIX2003 ()
#1 0x000beb8b in mono_handle_native_sigsegv (signal=11, ctx=0xbfffb560) at ../../../../mono/mini/mini-exceptions.c:1826
#2 0x0000e7a6 in mono_sigsegv_signal_handler (_dummy=11, info=0xbfffb520, context=0xbfffb560) at ../../../../mono/mini/mini.c:4846
#3 <signal handler called>
#4 0x03035274 in CA::Render::Shmem::copy_image ()
#5 0x03035232 in CABackingStoreCopyRenderImage ()
#6 0x03035060 in CA::Render::copy_render_value ()
#7 0x0303326d in -[CALayer(CALayerPrivate) _copyRenderLayer:layerFlags:commitFlags:] ()
#8 0x030330b4 in CALayerCopyRenderLayer ()
#9 0x030311d2 in CA::Context::commit_layer ()
#10 0x030310e1 in CALayerCommitIfNeeded ()
#11 0x03031069 in CALayerCommitIfNeeded ()
#12 0x03031069 in CALayerCommitIfNeeded ()
#13 0x0301f7b9 in CA::Context::commit_transaction ()
#14 0x0301f0d0 in CA::Transaction::commit ()
#15 0x0304f7d5 in CA::Transaction::observer_callback ()
#16 0x00dfafbb in __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ ()
#17 0x00d900e7 in __CFRunLoopDoObservers ()
#18 0x00d58bd7 in __CFRunLoopRun ()
#19 0x00d58240 in CFRunLoopRunSpecific ()
#20 0x00d58161 in CFRunLoopRunInMode ()
#21 0x03eb8268 in GSEventRunModal ()
#22 0x03eb832d in GSEventRun ()
#23 0x01bf242e in UIApplicationMain ()
#24 0x09d31c41 in ?? ()
#25 0x09d31b7a in ?? ()
#26 0x09d3157d in ?? ()
#27 0x09d314b9 in ?? ()
#28 0x09d31514 in ?? ()
#29 0x0000e56a in mono_jit_runtime_invoke (method=0x80a83f4, obj=0x0, params=0xbfffed1c, exc=0x0) at ../../../../mono/mini/mini.c:4733
#30 0x001c961b in mono_runtime_invoke (method=0x80a83f4, obj=0x0, params=0xbfffed1c, exc=0x0) at ../../../../mono/metadata/object.c:2615
#31 0x001cb2d7 in mono_runtime_exec_main (method=0x80a83f4, args=0x9faec00, exc=0x0) at ../../../../mono/metadata/object.c:3581
#32 0x001cabfd in mono_runtime_run_main (method=0x80a83f4, argc=0, argv=0xbfffee54, exc=0x0) at ../../../../mono/metadata/object.c:3355
#33 0x00095354 in mono_jit_exec (domain=0x6f91e58, assembly=0x9b4b480, argc=1, argv=0xbfffee50) at ../../../../mono/mini/driver.c:1094
#34 0x0027d299 in main ()
=================================================================
Got a SIGSEGV while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries
used by your application.
=================================================================
Unhandled Exception: System.NullReferenceException: Object reference not set to an instance of an object
at (wrapper managed-to-native) MonoTouch.UIKit.UIApplication:UIApplicationMain (int,string[],intptr,intptr)
at MonoTouch.UIKit.UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName) [0x00038] in /Users/plasma/Source/iphone-3/monotouch/UIKit/UIApplication.cs:26
答案 0 :(得分：0)
看起来你已经允许在iOS完成之前收集后备存储。更具体地说，是图像或图层。