SimpleStocks协议使用（Apple示例代码）-SimpleStocksprotocolusage(Applesamplecode)

1  

Here's the rub: The way I read the 1st line of code, dataSource is being sent the message graphViewDailyTradeInfoCount (which returns some numeric value specifying how many transactions occurred).

这是一个问题：我读取第一行代码的方式，dataSource正在发送消息graphViewDailyTradeInfoCount（返回一些指定发生了多少事务的数值）。

Correct.

正确。

If we assume 25 transactions, essentially [dataSource 25];

如果我们假设25个交易，基本上是[dataSource 25];

Incorrect (based on the [] and your description, you think we're sending 25 to the data source). After the call, dataCount = 25.

不正确（基于[]和您的描述，您认为我们正在向数据源发送25）。通话结束后，dataCount = 25。

The call is asking the data source to return data to us. It is passing ourself to the data source (:self) for information purposes but the intent of the request is to get information from the data source.

该调用要求数据源将数据返回给我们。它将自己传递给数据源（：self）以供参考，但请求的目的是从数据源获取信息。

Now that we have the 25 (stored in dataCount) we can do something with it.

现在我们有了25（存储在dataCount中），我们可以用它做点什么。

Similarly, in the second line of code, the data source is just returning the array. We aren't passing it an array.

类似地，在第二行代码中，数据源只是返回数组。我们没有将它传递给数组。

For the previous mini question:

对于之前的迷你问题：

NSInteger dataCount = [APLStockViewController graphViewDailyTradeInfoCount:self];

NSInteger dataCount = [APLStockViewController graphViewDailyTradeInfoCount：self];

This can't work because APLStockViewController is a class. We need to talk to an instance of the class (which is where self.dataSource comes in).

这不起作用，因为APLStockViewController是一个类。我们需要与类的实例（self.dataSource的来源）进行对话。

0  

I think you might be over complicating how delegates and datasources work. Datasource points to some instance of some object.

我认为你可能会使委托和数据源的工作方式变得复杂。数据源指向某个对象的某个实例。

When some object said it was a APLSimpleStockViewDataSource, it was saying that it implemented some methods, including graphViewDailyTradeInfoCount: and graphViewSortedMonths:. That object has SomeInstanceOfAPLSimpleStockView.datasource = self (or whatever the name of the class that you're working in was) somewhere in it's creation, like init or viewdidload

当一些对象说它是一个APLSimpleStockViewDataSource时，它说它实现了一些方法，包括graphViewDailyTradeInfoCount：和graphViewSortedMonths：。该对象具有SomeInstanceOfAPLSimpleStockView.datasource = self（或者您正在处理的类的名称），它在创建的某个位置，如init或viewdidload

It's the same as if you had some MyObject* myobj that implemented those methods, and you called [myobj graphViewSortedMonths:self

就像你有一些MyObject * myobj实现了那些方法一样，你调用了[myobj graphViewSortedMonths：self