Xcode 9 - “Fixed Width Constraints May Cause Clipp

问题:

I downloaded the new Xcode and in Interface Builder I'm having a ton of problems with warnings that say things like:

Fixed Width Constraints May Cause Clipping

It looks like this:

I do have localization for several languages and I understand the warning that in another language a label's size may change, but my app doesn't have this problem. I ran and tested it in Xcode 8 yesterday, it was fine. I don't want to spend hours and hours adding pointless new constraints.

Any suggested solutions?

回答1:

I was getting the same warnings even without multiple languages in my app, which led me to find out what was really going on. . .

There are a few different things going on here. I was able to silence the fixed-width warnings in my own app by changing the width of the object spacings from fixed width to greater than or equal or less than or equal.

This can be done by selecting the object in interface builder, going to the size inspector and changing it there:

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Or, select the constraint from the document outline, go to size inspector, and change it there:

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As far as the warning at the top of your screenshot:

Fixed leading and trailing constraints with a center constraint may cause clipping

Here is a screenshot from my own app in which I was getting the exact same warning:

I had the label with the @ sign set to leading and trailing to the buttons but also to align the center with the rating label. Once I removed the center alignment constraint, the warning disappeared, but I was left with an improperly laid out set of objects.

It is then that I resigned myself to embrace the Stack View. As annoying as it is to use, when you get all of the constraints and settings right, it lays out beautifully and with no warnings.

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Edit

As Repose writes in the comments, sometimes simply adding >= 0 will be what you need, as you are making sure two elements do not overlap.

回答2:

You can try Disabling "Respect Language Direction" on per Constraint basis to silence the warning and see if it helps. Select your constraint and open Attributes/Size Inspector. Please see image attached.

p.s. This solution works for iOS. For macOS try >= or <= to silence the warning.

回答3:

For labels and buttons which are localized this warning makes sense and you should provide the necessary constraints so your labels don't overlap. If they don't overlap now they might in the future, so it won't hurt to provide the constraints.

Xcode helps you add these constraints automatically:

In the document outline of your storyboard klick on the yellow arrow and either choose "fixed leading" or "fixed trailing", depending on where the text is on your screen (left or right). This will fix it for most issues.

If you have this issue with a Button without any text (only image), try to remove the "default title" which might still be set for the button:

回答4:

With Labels, you can set Lines is 0 and Autoshrink properties is Minimum Font Size to remove Fixed Width Constraints May Cause Clipping warnings, like this:

回答5:

For a UIButton by changing the title from plain to Attributed text also resolved my issue:-

回答6:

I know this question has already been answered but what I did to fix this error in my case was to add the "Aspect ratio" property and then eliminate the width or height constraint this worked pretty well and was less effort, and I managed to keep the same output and adapt my view for the different devices.

回答7:

Swift 4 , Xcode 9.1 :

About this issue, I think your object don't know what it's the correct center position in the context of it's superview, and using remove, greater than or other leading/trealing settings most of times don't work correctly. First, you must check the correct constraints of your superview.

If your superview/s are correctly setted, you can try to "explain" to your object what is the correct position in the view by setting the "horizontally in Container" constraint:

回答8:

I had the same problem, but when I changing to >= it automatically set the constant to 0, if I choose 60 for instance, the warning appears again. So I was in a loop with the problem.

I could fix embedding my Label in a View

Editor > Embed In > View

In Label I set Top, Bottom, Leading and Trailing with constant = 0

In View I set the constraints that I was expecting before.

回答9:

I had the same problem when moving to Xcode 9 and found an approach that's useful for certain kinds of layouts. In my case, I wanted a table header in which two columns (UILabels) were of fixed width and another was of variable width. Regardless of how I specified column widths (including using constraints greater than or equal instead of equal, etc.), I kept getting the warning about possible clipping. In my case, I wanted the variable width column (UILabel) to clip if necessary. I could have just ignored the warning, but don't like doing that.

The approach that worked here was to create a UIView with appropriate size constraints and embed the UILabel as a subview in the UIView. Then truncation happens if necessary and I get no warning. This works whether the UIView/embedded UILabel is in a StackView or not.

This is essentially the same approach as that of Haroldo Gondim but here you can see it also works with or without StackView.

The following image shows the approach, with and without StackView. "SpacerName" is a variable width UIView containing a label and "SpacerPD" is one with a fixed width of 80. [Colors are not significant; just there to show where the views are.]

回答10:

As you can see in the image below, I was having the error "Fixed Width Constraints May Cause Clipping" because although I had set my textbox to be vertically centered and my label to have a left margin constraint, I hadn't defined a constraint for the text box in relation to the label, so XCode was alerting me that the textbox could clip (be rendered above) the label.

After adding the left constraint to the text box to always stay some distance apart from the label the error was considered solved by XCode and it didn't bothered me with the constraint warning anymore.

回答11:

I had a similar issue when trying have the button with the same paddings from the edges of the super view.

I've ended up using horizontal center constraint and equal widths constraint to the super view.

回答12:

To Fix The Error: Fixed Width Constraints May Cause Clipping” and Other Localization You need to select the view/object, go to the "Show Size Inspector", find the Width Constraint and set the Constant to Greater or Equal to:

To Fix The Error: Leading/Trailing constraint is missing which may cause overlapping with other views

This means that the view/object Xcode is complaining about, is missing a Leading or Trailing Constraint to a neighboring view.

While holding control, drag to a near by view/object

Add a Leading or Trailing Constraint