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我正在尝试实现一个简单的今天小部件，其中包含一个具有固定高度的标签。

在文档中它说：

如果小部件有额外的内容要显示，您可以依靠自动布局约束来适当地调整小部件的高度。

但是，我不断收到“无法同时满足约束”的警告。

这是我尝试过的：

  1. 创建一个新的“Today Extension”目标，它创建带有“Hello World”标签和视图控制器的故事板。
  2. 将高度约束设置为“Hello World”标签。

在此处输入图像描述

当我跑步时，我得到：

2014-09-18 21:13:07.123 TestWidget[23381:871330] Unable to simultaneously satisfy constraints.
    Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) 
(
    "<NSLayoutConstraint:0x7f87c31126d0 V:[UILabel:0x7f87c3113230'Hello World Fixed Height'(21)]>",
    "<NSLayoutConstraint:0x7f87c30235b0 V:[_UILayoutGuide:0x7f87c30222b0]-(NSSpace(8))-[UILabel:0x7f87c3113230'Hello World Fixed Height']>",
    "<NSLayoutConstraint:0x7f87c3023600 V:[UILabel:0x7f87c3113230'Hello World Fixed Height']-(NSSpace(8))-[_UILayoutGuide:0x7f87c3022f00]>",
    "<_UILayoutSupportConstraint:0x7f87c3021980 V:[_UILayoutGuide:0x7f87c30222b0(0)]>",
    "<_UILayoutSupportConstraint:0x7f87c30218a0 V:|-(0)-[_UILayoutGuide:0x7f87c30222b0]   (Names: '|':UIView:0x7f87c3112f20 )>",
    "<_UILayoutSupportConstraint:0x7f87c3023360 V:[_UILayoutGuide:0x7f87c3022f00(0)]>",
    "<_UILayoutSupportConstraint:0x7f87c3023300 _UILayoutGuide:0x7f87c3022f00.bottom == UIView:0x7f87c3112f20.bottom>",
    "<NSLayoutConstraint:0x7f87c3326710 'UIView-Encapsulated-Layout-Height' V:[UIView:0x7f87c3112f20(628)]>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x7f87c31126d0 V:[UILabel:0x7f87c3113230'Hello World Fixed Height'(21)]>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.

我究竟做错了什么？使用自动布局创建具有固定高度的小部件的正确方法是什么？

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2 回答 2

1

我找到了一种通过引入包装视图来删除这些警告的方法，将所有其他视图放入此包装视图并为包装视图的高度约束设置低优先级。

快照

于 2015-07-11T12:56:03.440 回答
0

嗨，您需要做的是设置标签高度、宽度、前导和尾随，并使标签中心为 X 和 Y。当给出前导、顶部、尾随、底部时会发生什么是当您运行您的应用程序时，它会保持原样，所以您视图会被拉伸。如果你想使用任何前导，顶部，尾随，底部，你需要给底部空间'> ='它增加了超级视图的底部间距。简单易行的解决方案是从 superview 制作 centerX 和 centerY。它将视图准确地放置在屏幕或视图的中心。

学习目的访问：
简单：
http
://technet.weblineindia.com/mobile/using-auto-layout-in-xcode-6-for-universal-ios-app-development/高级：
http ://www.youtube .com/watch?v=G53PuA_TlXk&feature=youtu.be&list=UUtc1Jt_UTPsXpAGtvlr0nUQ

如您所见，我刚刚设置了 centerX、centerY、width、height、前导和尾随空格。

于 2014-10-10T02:22:43.297 回答