iphone - 按钮文本未显示且 xcode 崩溃

Question

我刚刚开始学习 IOS 开发。我花了几天时间试图解决这个问题，但我一无所获。希望有人能提供帮助。

我当时正在为 iPhone 开发一个计算器应用程序(只是为了练习)。我创建了一个按钮网格，但是当我开始创建最后一行时，xCode 在我创建或移动每个按钮后一直崩溃。我最终创建了布局，但是当我运行该应用程序时，底行的任何按钮都没有显示按钮文本(在 IOS 模拟器或我的 iPhone 上):

             +----+ +----+ +----+ +----+ +----+
             | 7  | | 8  | | 9  | | +  | | -  |
             |    | |    | |    | |    | |    |
             +----+ +----+ +----+ +----+ +----+

             +----+ +----+ +----+ +----+ +----+
             | 4  | | 5  | | 6  | | /  | | *  |
             |    | |    | |    | |    | |    |
             +----+ +----+ +----+ +----+ +----+

             +----+ +----+ +----+ +----+ +----+
             | 1  | | 2  | | 3  | |    | | AC |
             |    | |    | |    | |    | |    |
             +----+ +----+ +----+ |    | +----+
                                  | =  |
             +----+ +----+ +----+ |    | +----+
             |    | |    | |    | |    | |    |
             |    | |    | |    | |    | |    |
             +----+ +----+ +----+ +----+ +----+

如果我将按钮从底部一行一个移动到顶部，文本会显示在它们上面，但仍然不在底部一行:

                    +----+ +----+        +----+
                    | .  | | +- |        | C  |
                    |    | |    |        |    |
                    +----+ +----+        +----+

             +----+ +----+ +----+ +----+ +----+
             | 7  | | 8  | | 9  | | +  | | -  |
             |    | |    | |    | |    | |    |
             +----+ +----+ +----+ +----+ +----+

             +----+ +----+ +----+ +----+ +----+
             | 4  | | 5  | | 6  | | /  | | *  |
             |    | |    | |    | |    | |    |
             +----+ +----+ +----+ +----+ +----+

             +----+ +----+ +----+ +----+ +----+
             | 1  | | 2  | | 3  | |    | | AC |
             |    | |    | |    | |    | |    |
             +----+ +----+ +----+ |    | +----+
                                  | =  |
             +----+               |    |
             |    |               |    |
             |    |               |    |
             +----+               +----+

然后，当我将最后一个按钮移到顶部时，新的底部行停止显示文本:

             +----+ +----+ +----+        +----+
             | 0  | | .  | | +- |        | C  |
             |    | |    | |    |        |    |
             +----+ +----+ +----+        +----+

             +----+ +----+ +----+ +----+ +----+
             | 7  | | 8  | | 9  | | +  | | -  |
             |    | |    | |    | |    | |    |
             +----+ +----+ +----+ +----+ +----+

             +----+ +----+ +----+ +----+ +----+
             | 4  | | 5  | | 6  | | /  | | *  |
             |    | |    | |    | |    | |    |
             +----+ +----+ +----+ +----+ +----+

             +----+ +----+ +----+ +----+ +----+
             | 1  | | 2  | | 3  | |    | | AC |
             |    | |    | |    | |    | |    |
             +----+ +----+ +----+ |    | +----+
                                  |    |
                                  |    |
                                  |    |
                                  |    |
                                  +----+

然后我向上移动等号按钮，新的底行无法显示文本:

                                  |    |
                                  |    |
             +----+ +----+ +----+ | =  | +----+
             | 0  | | .  | | +- | |    | | C  |
             |    | |    | |    | |    | |    |
             +----+ +----+ +----+ +----+ +----+

             +----+ +----+ +----+ +----+ +----+
             | 7  | | 8  | | 9  | | +  | | -  |
             |    | |    | |    | |    | |    |
             +----+ +----+ +----+ +----+ +----+

             +----+ +----+ +----+ +----+ +----+
             | 4  | | 5  | | 6  | | /  | | *  |
             |    | |    | |    | |    | |    |
             +----+ +----+ +----+ +----+ +----+

             +----+ +----+ +----+        +----+
             |    | |    | |    |        |    |
             |    | |    | |    |        |    |
             +----+ +----+ +----+        +----+

这真是令人沮丧!我在一个新的应用程序中再次开始得到同样的东西，总是没有显示的最低对齐行。如果我切换到 3.5" View ，问题仍然存在。我尝试进一步间隔按钮，尝试更改所有文本参数，更改 View 以禁用自动调整 subview 并将模式从缩放更改为适合，但这仍在发生.我找不到任何其他描述此问题的帖子，这看起来很奇怪，因为它很容易重新创建。请帮助。

Answer 1

我建议仅在非常特殊的情况下才使用 iOS 6 的新自动布局选项。我已经非常深入地测试了这个选项并发现了很多错误，例如:

• 在控制台中出现指示 apple bug 的消息
• 它会显着减慢您的用户界面
• 布局约束突然消失
• 应用有时会崩溃并显示未记录的错误消息

目前使用自动布局非常令人沮丧。我没有使用自动布局，而是使用了

- (void)viewDidLayoutSubviews {}

以编程方式调整我的 UI，这更加容易和快速(在开发和运行时)。