四、添加路由的两种方式

在Flask中，添加路由有两种方式：（一般情况下都是用第一种方式）

第一种：常见的装饰器模式

@app.route("/")
def index():
    return "Hello World"

通过这种方式，将rule与视图函数对应起来

第二种：通过阅读装饰器模式添加路由的源码发现

def route(self, rule, **options):
    """A decorator that is used to register a view function for a
    given URL rule.  This does the same thing as :meth:`add_url_rule`
    but is intended for decorator usage::

        @app.route('/')
        def index():
            return 'Hello World'

    For more information refer to :ref:`url-route-registrations`.

    :param rule: the URL rule as string
    :param endpoint: the endpoint for the registered URL rule.  Flask
                     itself assumes the name of the view function as
                     endpoint
    :param options: the options to be forwarded to the underlying
                    :class:`~werkzeug.routing.Rule` object.  A change
                    to Werkzeug is handling of method options.  methods
                    is a list of methods this rule should be limited
                    to (``GET``, ``POST`` etc.).  By default a rule
                    just listens for ``GET`` (and implicitly ``HEAD``).
                    Starting with Flask 0.6, ``OPTIONS`` is implicitly
                    added and handled by the standard request handling.
    """

    def decorator(f):
        endpoint = options.pop("endpoint", None)
        self.add_url_rule(rule, endpoint, f, **options)
        return f

    return decorator

是通过self.add_url_rule这个方式建立起rule与视图函数的对应关系的，所以可以这样添加，

def home():
    return "Hello, home!"


app.add_url_rule("/home", endpoint=None, view_func=home)

endpoint:给rule起一个别名，相当于django path路由函数中的name。