将SEH异常映射到NET异常

Win32 SEH异常也可以作为.NET异常捕获。在下面的代码中，托管函数（main）调用本机函数（f），该函数抛出SEH exception exception_INT_DIVIDE_BY_ZERO。大体上，这个异常是在处理System：：ExceptionA类型异常的catch块中捕获的。

// ExceptionHandling2.cpp

// compile with "cl /clr ExceptionHandling2.cpp"

// As I will discuss later, #pargma managed is not recommended; it is only // used to show exceptions thrown across managed / unmanaged boundaries // without using two source files #pragma unmanaged int f() {

#pragma managed int main() {

catch (System::ExceptionA ex) {

System::Console::WriteLine(ex->GetType()->FullName);

如果编译并执行此应用程序，则类型名称System.DivideByZeroException将写入catch块中。大多数SEH异常代码将映射到类型System：：Runtime：：InteropServices：：SEH exception。映射到System.DivideByZeroException是少数几种特殊情况之一。表7-4显示了存在特殊映射的SEH异常。

Win32 Exception Code		Hex Value	Managed Exception
EXCEPTION_	ACCESS_VIOLATION	C0000005	System:	:AccessViolationException
EXCEPTION_	NO_MEMORY	C0000017	System:	:OutOfMemoryException
EXCEPTION_	ARRAY_BOUNDS_EXCEEDED	C000008C	System:	:IndexOutOfRangeException
EXCEPTION_	FLT_DENORMAL_OPERAND	C000008D	System:	:FormatException
EXCEPTION	FLT_DIVIDE_BY_ZERO	C000008E	System:	:DivideByZeroException
EXCEPTION_	FLT_INEXACT_RESULT	C000008F	System:	:ArithmeticException
EXCEPTION_	FLT_INVALID_OPERATION	C0000090	System:	:ArithmeticException
EXCEPTION_	FLT_OVERFLOW	C0000091	System:	:OverflowException
EXCEPTION_	FLT_STACK_CHECK	C0000092	System:	:ArithmeticException
EXCEPTION_	FLT_UNDERFLOW	C0000093	System:	:ArithmeticException
EXCEPTION_	INT_DIVIDE_BY_ZERO	C0000094	System:	:DivideByZeroException
EXCEPTION_	INT_OVERFLOW	C0000095	System:	:OverflowException
EXCEPTION_	STACK_OVERFLOW	C00000FD	System:	:StackOverflowException
All other SEH exceptions			System::Runtime:: InteropServices::SEHException

 

如上表所示，访问冲突（0xC0000005）自动映射到System：：AccessViolationException。此异常类型已在.NET 2.0中引入。在.NET的早期版本中，将引发System：：null引用异常。由于这是一个中断性更改，您可以切换回原来的行为，配置文件如下所示：

<configuration> <runtime>

<legacyNullReferenceExceptionPolicy enabled="1"/> </runtime> </configuration>