我做了一个CLEAN ALL，我已经重置了模拟器，但我无法解释为什么我得到以下内容:(参见'已解决的待处理断点'行，'无法插入'）
Loaded assembly: /Developer/MonoTouch/usr/lib/mono/2.1/monotouch.dll [External]
Loaded assembly: /Developer/MonoTouch/usr/lib/mono/2.1/System.Core.dll [External]
Loaded assembly: /Users/drisszouak/Projects/ZenVelopes/ZenVelopes/bin/iPhoneSimulator/Debug/ZenVelopes.exe
Resolved pending breakpoint at 'EnvelopeViewController.xib.cs:76' to Void ZenVelopes.EnvelopeViewController:HandleBtnNewEnvelopeClicked ():0.
Could not insert pending breakpoint at 'EnvelopeViewController.xib.cs:69'. Perhaps the source line does not contain any statements, or the source does not correspond to the current binary.
Loaded assembly: /Developer/MonoTouch/usr/lib/mono/2.1/Mono.Data.Sqlite.dll [External]
Loaded assembly: /Developer/MonoTouch/usr/lib/mono/2.1/System.Data.dll [External]
Loaded assembly: /Developer/MonoTouch/usr/lib/mono/2.1/System.dll [External]
Loaded assembly: /Developer/MonoTouch/usr/lib/mono/2.1/System.Transactions.dll [External]
Loaded assembly: /Developer/MonoTouch/usr/lib/mono/2.1/System.Xml.dll [External]
第69和76行的代码是有效代码，是工具栏按钮的事件处理程序。然后当我点击其中一个按钮时，我得到一个空引用异常。