If the database doesn't exist, an exception is thrown, and the DBManager constructor creates the database itself.

如果数据库不存在，将抛出一个异常，并且DBManager构造函数自己将创建数据库。

youdao

The runtime will stop any exceptions trying to leave a type constructor and wrap the exception inside of a new TypeInitializationException object.

运行库将停止任何尝试保留类型构造函数的异常，并将该异常包装到一个新的 TypeInitializationException 对象内。

youdao

The constructor for the file_lock class accepts the name of the file to be locked, and it's important to open the file before lock is invoked; otherwise, an exception will be thrown.

file_lock类的构造函数接受要锁定的文件的名称，一定要在调用lock之前打开文件；否则会抛出异常。

youdao