根据设计标准，你应该

坚持每一个假设。平均每五行就有一个断言。

using System.Diagnostics;

object GetObject()
{...}

object someObject = GetObject();
Debug.Assert(someObject != null);

作为一个免责声明，我应该提到我还没有发现实现这个IRL是实际的。但这是他们的标准。

断言用于捕获程序员(您的)错误，而不是用户错误。只有在用户不可能触发断言时才应该使用它们。例如，如果你正在编写一个API，在API用户调用的任何方法中，都不应该使用断言来检查参数是否为空。但是它可以在一个私有方法中使用，而不是作为API的一部分公开，以断言您的代码永远不会在不应该传递null参数时传递null参数。

当我不确定时，我通常更喜欢异常而不是断言。

摘自Code Complete (Wikipedia):

8 Defensive Programming 8.2 Assertions An assertion is code that’s used during development—usually a routine or macro—that allows a program to check itself as it runs. When an assertion is true, that means everything is operating as expected. When it’s false, that means it has detected an unexpected error in the code. For example, if the system assumes that a customer-information file will never have more than 50,000 records, the program might contain an assertion that the number of records is lessthan or equal to 50,000. As long as the number of records is less than or equal to 50,000, the assertion will be silent. If it encounters more than 50,000 records, however, it will loudly “assert” that there is an error in the program. Assertions are especially useful in large, complicated programs and in high reliability programs. They enable programmers to more quickly flush out mismatched interface assumptions, errors that creep in when code is modified, and so on. An assertion usually takes two arguments: a boolean expression that describes the assumption that’s supposed to be true and a message to display if it isn’t. (…) Normally, you don’t want users to see assertion messages in production code; assertions are primarily for use during development and maintenance. Assertions are normally compiled into the code at development time and compiled out of the code for production. During development, assertions flush out contradictory assumptions, unexpected conditions, bad values passed to routines, and so on. During production, they are compiled out of the code so that the assertions don’t degrade system performance.

我不会在产品代码中使用它们。抛出异常，捕获和记录。

在asp.net中也需要小心，因为断言可以显示在控制台上并冻结请求。

您应该始终使用第二种方法(抛出异常)。

同样，如果你是在生产环境中(并且有一个发布版本)，抛出一个异常(在最坏的情况下让应用程序崩溃)比处理无效值和可能破坏客户数据(这可能要花费数千美元)要好。

我不知道它在c#和。net中是怎样的，但在C中assert()只在使用- ddebug编译时工作-如果没有编译，最终用户将永远不会看到assert()。仅供开发人员使用。我经常使用它，它有时更容易跟踪错误。