January 2020
Intermediate to advanced
356 pages
6h 4m
Chinese
Content preview from Swift游戏开发经典实例
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338
｜
第
11
章
11.6
使用
watchpoint
问题
我们想了解某个变量什么时候被改变了。
解决方案
当变量从某个值改变成其他值时，我们想让
Xcode
停止执行，这就需要使用到观察
点（
watchpoint
）。在变量上设置观察点的步骤如下：
1.
首先，用一个断点让程序暂停执行。当程序停下后，在调试控制台中出现可见
变量列表。
2.
在想监视的变量上添加监视点。找到想监视的变量，单击鼠标右键，然后选择
“
Watch[
变量名
]
”，如图
11-6
所示。
图
11
-
6
：创建监视点
3.
继续执行程序。
当监视到该变量值发生改变时，程序会暂停执行。
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.