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) } }

如果您正在使用材质组件主题，您可以通过将背景颜色设置为透明，然后将布局的背景设置为四舍五入来覆盖BottomSheetDialog的默认行为。

    <style name="Theme.MyApp" parent="Theme.MaterialComponents.DayNight.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="bottomSheetDialogTheme">@style/BottomSheetDialog</item>
    </style>

    <style name="BottomSheetDialog" parent="ThemeOverlay.MaterialComponents.BottomSheetDialog">
        <item name="bottomSheetStyle">@style/bottomSheetStyleWrapper</item>
    </style>

    <style name="bottomSheetStyleWrapper" parent="Widget.MaterialComponents.BottomSheet.Modal">
        <item name="android:backgroundTint">@android:color/transparent</item>
    </style>

rounded_corner.xml:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <solid android:color="@color/white"/>
    <corners android:topLeftRadius="26dp"
        android:topRightRadius="26dp"/>

</shape>

然后将形状应用到你的底部表格根布局的背景:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/rounded_corner">

    <!-- 
       other layout components
     -->

</LinearLayout>

注意，如果你在底部表单布局中使用Webview这样的组件，你可能无法实现预期的圆角，因为Webview有一个默认的白色背景。在这种情况下，你可以像这样简单地删除背景:

webView.setBackgroundColor(0);

简单的解决方案:

class TopRoundedCornersFragment : BottomSheetDialogFragment() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        setStyle(STYLE_NORMAL, R.style.AppBottomSheetDialogTheme)
    }
}

在styles.xml

<style name="BottomSheetStyle" parent="Widget.Design.BottomSheet.Modal">
    <item name="android:background">@drawable/bottom_sheet_dialog_bg</item>
</style>

<style name="AppBottomSheetDialogTheme" parent="Theme.Design.Light.BottomSheetDialog">
    <item name="bottomSheetStyle">@style/BottomSheetStyle</item>
</style>

最后，创建一个顶部圆角可绘制资源(bottom_sheet_dialog_bg.xml)

<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">

    <solid android:color="@android:color/white" />
    <corners
        android:topLeftRadius="4dp"
        android:topRightRadius="4dp" />

</shape>

这个答案只针对背景色设置为彩色的问题。透明后，设置一个绘图与圆形背景的布局。

没有一个答案能让我把背景色设置为“彩色”。透明的，除非重写setupDialog()解决方案:

@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);
    ...
    ((View) contentView.getParent()).setBackgroundColor(ContextCompat.getColor(getContext(), android.R.color.transparent));
}

但是你在这里为对话框设置的contentView不是你在onCreateView()中膨胀时在onViewCreated()中获得的视图。它打破了标准流程，所以可能会出现问题，比如你不能使用视图绑定- onViewCreated()中的Kotlin Android扩展

所以我稍微调整了一下设置onActivityCreated()的背景:

override fun onActivityCreated(savedInstanceState: Bundle?) {
    super.onActivityCreated(savedInstanceState)
    (view?.parent as View).setBackgroundColor(Color.TRANSPARENT)
  }

希望这对遇到同样麻烦的人有所帮助

步骤1:

创建一个命名为rounded_background.xml的res/drawable:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
  android:shape="rectangle">
  <corners
    android:topLeftRadius="32dp"
    android:topRightRadius="32dp" />
  <solid android:color="#D81B60" />
</shape>

步骤2:

创建这个样式来删除对话框背景:

<style name="NoBackgroundDialogTheme" parent="Theme.AppCompat.Light.Dialog">
    <item name="android:windowBackground">@null</item>
</style>

步骤3:

使用setBackgroundResource()将可绘制对象设置为对话框的根视图，并通过覆盖getTheme()方法设置样式

Java:

public class MyDialogFragment extends BottomSheetDialogFragment {

    @Override
    public int getTheme() {
        return R.style.NoBackgroundDialogTheme;
    }

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {

        View view = View.inflate(requireContext(), R.layout.bottom_sheet_profile, null);
        view.setBackgroundResource(R.drawable.rounded_background);
        return view;

    }
}

科特林：

class MyDialogFragment : BottomSheetDialogFragment() {

    override fun getTheme() = R.style.NoBackgroundDialogTheme

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {

        val view: View = View.inflate(requireContext(), R.layout.bottom_sheet_profile, null)
        view.setBackgroundResource(R.drawable.rounded_background)
        return view
    }

}

结果:

如果(view.setBackgroundResource(R.drawable.rounded_background))这一行不能工作，然后尝试设置片段的Xml格式的背景。

在STATE_EXPANDED上禁用圆角平化的短解决方案:

@SuppressLint("RestrictedApi")
override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
    val dialog = super.onCreateDialog(savedInstanceState)
    
    //Disable animator that flats the rounded corners
    (dialog as BottomSheetDialog).behavior.disableShapeAnimations()

    return dialog
}