如果你使用材质组件的最后一个版本，你只需要覆盖ShapeAppearance.MaterialComponents.LargeComponent(因为底部表使用这个形状)，并设置你想要的值:

 <style name="ShapeAppearance.YourApp.LargeComponent" parent="ShapeAppearance.MaterialComponents.LargeComponent">
        <item name="cornerFamily">rounded</item>
        <item name="cornerSize">12dp</item>
 </style>

然后设置你的应用样式:

<item name="shapeAppearanceLargeComponent">@style/ShapeAppearance.YourApp.LargeComponent</item>

Gabriele Mariotti的方法与此类似，也很有效，但这个方法更简单。

创建一个自定义的圆角绘图，并将其设置为你的BottomSheetDialogFragment的布局根的背景

<?xml version="1.0" encoding="UTF-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">

<solid android:color="@color/colorPrimary" />

<corners
    android:bottomLeftRadius="0dp"
    android:bottomRightRadius="0dp"
    android:topLeftRadius="12dp"
    android:topRightRadius="12dp" />

</shape>

然后简单地将下面的代码添加到您的BottomSheetDialogFragment类

@Override
public void setupDialog(Dialog dialog, int style) {
    super.setupDialog(dialog, style);
    View contentView = View.inflate(getContext(), 
R.layout.fragment_bottom_sheet, null);
    dialog.setContentView(contentView);

    CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) ((View) contentView.getParent())
            .getLayoutParams();
    CoordinatorLayout.Behavior behavior = params.getBehavior();
    ((View) contentView.getParent()).setBackgroundColor(ContextCompat.getColor(getContext(), android.R.color.transparent));
}

你甚至可以像下面这样使用参数来设置边距

params.setMargins(50, 0, 50, 0);

你必须改变底部的主题，以实现顶部圆形布局

创建一个自定义绘制background_bottom_sheet_dialog_fragment.xml:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
   android:shape="rectangle">
    <corners
       android:topLeftRadius="8dp"
        android:topRightRadius="8dp" />
    <padding android:top="0dp" />
    <solid android:color="@color/white" />
</shape>

然后在styles.xml上使用drawable作为背景覆盖bottomSheetDialogTheme:

<!--Bottom sheet-->
<style name="BottomSheet" parent="@style/Widget.Design.BottomSheet.Modal">
    <item 
    name="android:background">@drawable/background_bottom_sheet_dialog_fragment
    </item>
</style>

<style name="BaseBottomSheetDialog" 
    parent="@style/Theme.Design.Light.BottomSheetDialog">
    <item name="android:windowIsFloating">false</item>
    <item name="bottomSheetStyle">@style/BottomSheet</item>
</style>

<style name="BottomSheetDialogTheme" parent="BaseBottomSheetDialog" />

这将改变你的底页的背景布局

BottomSheetDialog

class SheetFragment() : BottomSheetDialogFragment() {

    lateinit var binding: SheetFragmentBinding;

  override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
    val dialog = super.onCreateDialog(savedInstanceState) as BottomSheetDialog;
    val view = View.inflate(context, R.layout.fragment_bottom_sheet, null);

    binding = DataBindingUtil.bind(view)!!;
    binding.viewModel = SheetFragmentVM();

    dialog.setContentView(view);

    var bottomSheetBehavior = BottomSheetBehavior.from(view.parent as View);
    bottomSheetBehavior.setPeekHeight(BottomSheetBehavior.PEEK_HEIGHT_AUTO);

    bottomSheetBehavior.setBottomSheetCallback(object : 
     BottomSheetBehavior.BottomSheetCallback() {
        override fun onStateChanged(bottomSheet: View, newState: Int) {
            if (BottomSheetBehavior.STATE_EXPANDED == newState) {
               // do on STATE_EXPANDED
            }
            if (BottomSheetBehavior.STATE_COLLAPSED == newState) {
                // do on STATE_COLLAPSED
            }

            if (BottomSheetBehavior.STATE_HIDDEN == newState) {
                dismiss()

            }
        }

        override fun onSlide(bottomSheet: View, slideOffset: Float) {
           // do on slide
        }
    })

    return dialog
}

我找到了一个简单的解决办法。 使用com.google.android.material:material:1.6.1

class MyBottomSheet: BottomSheetDialogFragment() {
    
      override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
            super.onViewCreated(view, savedInstanceState)
            disableShapeAnimation()
        }
    
      @SuppressLint("RestrictedApi", "VisibleForTests")
      private fun disableShapeAnimation() {
            try {
                val dlg = dialog as BottomSheetDialog
                dlg.behavior.disableShapeAnimations()
            } catch (ex: Exception) {
                Log.e("BaseBottomSheet", "disableShapeAnimation Exception:", ex)
            }
        }
}

最简单和最干净的解决方案，对我来说，是把以下4行放在我的片段类的onViewCreated(View View, Bundle savedInstanceState)方法中:

@Override
public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
    View bottomSheet = (View) view.getParent();
    bottomSheet.setBackgroundTintMode(PorterDuff.Mode.CLEAR);
    bottomSheet.setBackgroundTintList(ColorStateList.valueOf(Color.TRANSPARENT));
    bottomSheet.setBackgroundColor(Color.TRANSPARENT);
}

这将允许您的自定义绘制圆角，以正确显示一旦设置为您的片段布局的顶层视图的背景。

本质上，这将覆盖默认的BottomSheetFragment属性关于颜色，tintMode和tintList。

使用它，就不需要打乱样式资源。

Create a shape drawable .. which we will use as background for bottom sheet . Provide the appropriate value for radius of top left and right corner . <?xml version="1.0" encoding="utf-8"?> <shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle"> <corners android:topLeftRadius="24dp" android:topRightRadius="24dp" /> <padding android:top="2dp" /> <solid android:color="@color/white" /> </shape> Now create style for " Bottom sheet dialog fragment " <style name="BottomSheet" parent="@style/Widget.Design.BottomSheet.Modal"> <item name="android:background">@drawable/drawable_bottomsheet_background</item> </style> <style name="BaseBottomSheetDialog" parent="@style/Theme.Design.Light.BottomSheetDialog"> <item name="android:windowIsFloating">false</item> <item name="bottomSheetStyle">@style/BottomSheet</item> </style> <style name="BottomSheetDialogTheme" parent="BaseBottomSheetDialog" /> Now create a custom class that will extend BottomSheetDilogFragment ,where you provide your style . open class CustomRoundBottomSheet : BottomSheetDialogFragment() { override fun getTheme(): Int = R.style.BottomSheetDialogTheme override fun onCreateDialog(savedInstanceState: Bundle?): Dialog = BottomSheetDialog(requireContext(), theme) } Now use this class wherever you want to have round corner bottom sheet . eg class BottomSheetSuccess : CustomRoundBottomSheet() { override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? { return inflater.inflate(R.layout.bottomsheet_shopcreate_success, container, false) } override fun onViewCreated(view: View, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) } }