iOS版故事板在XCode 6.4中缺少约束图标，适用于最初在早期版本的iOS下编写的应用程序(Constraint icons missing from iOS8 Storyboard in XCo

iOS版故事板在XCode 6.4中缺少约束图标，适用于最初在早期版本的iOS下编写的应用程序(Constraint icons missing from iOS8 Storyboard in XCode 6.4 for app that was originally written under earlier versions of iOS)

我为iOS4或iOS5编写了一个应用程序。 我将它升级到iOS6。 添加新约束是相当痛苦的（我必须几乎完全重做故事板，我不得不创建一堆约束，因为它们以前不存在），但我完成了它。 现在我使用XCode 6.4升级到iOS8。 我在iOS8中编写了其他应用程序，约束图标始终位于底部; 其中有3个：对齐，固定和解析自动布局。 但是，在这个较旧的应用程序中，所有这些图标都丢失了（同样中间的W Any H Any也丢失了）。 其中一个约束是错误的，但我无法解决它，因为我没有任何约束图标。 我该如何取回它们？

这是一个显示约束图标的新应用程序：

这是缺少约束图标的旧应用程序：

I wrote an app for iOS4 or iOS5. I upgraded it to iOS6. Adding the new constraints were rather traumatic (I had to almost completely redo the Storyboard and I had to create a bunch of constraints since they didn't exist before), but I got through it. Now I'm upgrading to iOS8 using XCode 6.4. I have written other apps in iOS8 and the constraint icons are always on the bottom; there are 3 of them: Align, Pin, and Resolve Auto-Layout. However, in this older app, all of these icons are missing (also the W Any H Any in the middle is missing as well). One of the constraints is wrong, but I can't fix it because I don't have any constraint icons. How do I get them back?

Here is a new app that shows the constraint icons:

Here is the old app with the constraint icons missing:

最满意答案

选择故事板（在左侧）和文件检查器（在右侧;屏幕截图中不存在，您必须故意显示它）。 “文件”检查器具有“使用自动布局”复选框。 如果故事板不使用自动布局，您将看不到这些约束图标。

Select the storyboard (on the left) and the File inspector (on the right; not present in your screen shots, you'll have to show it deliberately). The File inspector has a Use Auto Layout checkbox. If the storyboard doesn't use auto layout, you won't see those constraint icons.