约束布局ConstraintLayout ，报错：This view is not constrained vertically

This view is not constrained vertically: at runtime it will jump to the left unless you add a vertic 解决方案：  1.切换xml到design试图下  2.选中ConstraintLayout右键选择Constraint Layout中的Infer Constraints \ 原因：要两个方向才可

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