ios - 自动布局错误无法同时满足 UIScrollView 的约束

我有一个 UIScrollView 来显示 UIImageViews。 ImageViews 在运行时根据用户先前保存的图像数量以编程方式插入。我收到以下错误:

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:0x17029cd90 H:[UIView:0x15cd31e70]-(0)-|   (Names: '|':UIScrollView:0x15cd326b0 )>",
"<NSLayoutConstraint:0x17029d060 UIScrollView:0x15cd326b0.trailingMargin == UIView:0x15cd31e70.trailing>"

我做了基本的自动布局， ScrollView 在 0 点处固定在所有四个边上。然后我添加一个 contentView 作为 UIScrollView 的 subview (普通 UIView)，它也固定在 0 点的所有四个边上。

编辑 Storyboard 约束图像

我在代码中给 contentView 一个宽度，如下所示:

    CGSize pagesScrollViewSize = self.scrollView.frame.size;

        NSDictionary *views     = @{ @"contentView"       :   self.contentView};

        NSDictionary *metrics   = @{ @"width"           :   @(pagesScrollViewSize.width * self.mutableArray.count) };

        NSArray *constraints;
        constraints = [NSLayoutConstraint constraintsWithVisualFormat"H:|-[contentView(width)]-|" options:0 metrics:metrics views:views];
        [self.scrollView addConstraints:constraints];

[self loadVisiblePages];

UIImageViews 的添加方式是这样的，UIImageViews 的添加是根据发生到 ViewController 的 segue 时设置的页数来添加的。

-(void)loadVisiblePages{

        CGRect frame = self.scrollView.bounds;
        frame.origin.x = frame.size.width * self.page;
        frame.origin.y = 0.0f;

        ImageForArchiving *newImageObject = (ImageForArchiving*)self.mutableArray