Question

我创建了一个tableviewcell。在它是一个图像。我想在列的整个宽度上显示图像。为此，我添加了所有设置为零的约束： - 领先的空间 - 尾随空间 - 顶层空间 - 底部空间我还定义了一个纵横比约束8：6来获得图像的正确宽高比。

在Interface Builder中，我得到了＆＃34;红色箭头＆＃34;错误＆＃34;需要约束：X的宽度位置＆＃34;。

当我运行代码（它是可编译的）时，它显示得很好。但是我得到运行时约束警告：

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. 
(
    "<NSLayoutConstraint:0x60800008cfd0 UILayoutGuide:0x6080001a5080'UIViewSafeAreaLayoutGuide'.bottom == UIImageView:0x7fc9fa90fa10.bottom + 8   (active)>",
    "<NSLayoutConstraint:0x60800008d2a0 UIImageView:0x7fc9fa90fa10.centerY == UILayoutGuide:0x6080001a5080'UIViewSafeAreaLayoutGuide'.centerY   (active)>",
    "<NSLayoutConstraint:0x60800008d2f0 UIImageView:0x7fc9fa90fa10.top == UILayoutGuide:0x6080001a5080'UIViewSafeAreaLayoutGuide'.top + 7   (active)>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x60800008d2a0 UIImageView:0x7fc9fa90fa10.centerY == UILayoutGuide:0x6080001a5080'UIViewSafeAreaLayoutGuide'.centerY   (active)>

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.

我看不出我做错了什么，有人能指出我正确的方向吗？

Answer 1

问题是，只要你的单元格大小没有8：6的比例，你的约束就会发生冲突。

有几种方法可以解决此问题，但我认为最简单的方法是使用leading约束替换trailing和center horizontally约束。图像现在将居中，其高度由单元格的高度设置，其宽度将由纵横约束设置。唯一需要注意的是，如果单元格变得比8：6更窄，那么图像将延伸到左/右边缘之外。

UITableViewCell图像全尺寸，具有正确的宽高比

1 个答案: