这是我第一次使用 Android studio，我不知道这些错误是什么意思，也不知道它们意味着什么在这里输入图像描述
[Render Problem Failed to load AppCompat ActionBar with unknown error. Missing Constraints in ConstraintLayout
This view is not constrained. It only has designtime positions, so it will jump to (0,0) at runtime unless you add the constraints The layout editor allows you to place widgets anywhere on the canvas, and it records the current position with designtime attributes (such as layout_editor_absoluteX). These attributes are not applied at runtime, so if you push your layout on a device, the widgets may appear in a different location than shown in the editor. To fix this, make sure a widget has both horizontal and vertical constraints by dragging from the edge connections.]
最佳答案
打开，res --> values --> styles.xml，在这里你会发现这样一行:
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
将 DarkActionBar 更改为 NoActionBar
关于android - 无法加载 AppCompat ActionBar，出现未知错误。Android Studio 3.1.3，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/50940219/