Android BottomSheetDialogFragment 是在com.google.android.material 中
BottomSheetDialogFragment 是继承AppCompatDialogFragment，AppCompatDialogFragment 继承DialogFragment，最后DialogFragment 继承的 Fragment
既然BottomSheetDialogFragment 最后继承的Fragment 显然他也是有自己的生命周期的。
BottomSheetDialogFragment 源码分析
//官方翻译
//Modal bottom sheet. This is a version of androidx.fragment.app.DialogFragment that shows a bottom sheet using BottomSheetDialog instead of a floating dialog.
//模态底板。这是androidx.fragment.app.DialogFragment的一个版本，它使用BottomSheetDialog而不是浮动对话框而是显示底部工作表。
public class BottomSheetDialogFragment extends AppCompatDialogFragment {
@NonNull
@Override
public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {
return new BottomSheetDialog(getContext(), getTheme());
}
明显的看出 BottomSheetDialogFragment在重写onCreateDialog 中 new BottomSheetDialog
BottomSheetDialog 源码
public BottomSheetDialog(@NonNull Context context) {
this(context, 0);
....
}
public BottomSheetDialog(@NonNull Context context, @StyleRes int theme) {
super(context, getThemeResId(context, theme));
}
private static int getThemeResId(@NonNull Context context, int themeId) {
if (themeId == 0) {
// If the provided theme is 0, then retrieve the dialogTheme from our theme
TypedValue outValue = new TypedValue();
if (context.getTheme().resolveAttribute(R.attr.bottomSheetDialogTheme, outValue, true)) {
themeId = outValue.resourceId;
} else {
// bottomSheetDialogTheme is not provided; we default to our light theme
themeId = R.style.Theme_Design_Light_BottomSheetDialog;
}
}
return themeId;
}
@Override
public void setContentView(@LayoutRes int layoutResId) {
super.setContentView(wrapInBottomSheet(layoutResId, null, null));
}
@Override
public void setContentView(View view) {
super.setContentView(wrapInBottomSheet(0, view, null));
}
@Override
public void setContentView(View view, ViewGroup.LayoutParams params) {
super.setContentView(wrapInBottomSheet(0, view, params));
}
private View wrapInBottomSheet(
int layoutResId, @Nullable View view, @Nullable ViewGroup.LayoutParams params) {
ensureContainerAndBehavior();
CoordinatorLayout coordinator = (CoordinatorLayout) container.findViewById(R.id.coordinator);
if (layoutResId != 0 && view == null) {
view = getLayoutInflater().inflate(layoutResId, coordinator, false);
}
if (edgeToEdgeEnabled) {
ViewCompat.setOnApplyWindowInsetsListener(
bottomSheet,
new OnApplyWindowInsetsListener() {
@Override
public WindowInsetsCompat onApplyWindowInsets(View view, WindowInsetsCompat insets) {
if (edgeToEdgeCallback != null) {
behavior.removeBottomSheetCallback(edgeToEdgeCallback);
}
if (insets != null) {
edgeToEdgeCallback = new EdgeToEdgeCallback(bottomSheet, insets);
behavior.addBottomSheetCallback(edgeToEdgeCallback);
}
return insets;
}
});
}
bottomSheet.removeAllViews();
if (params == null) {
bottomSheet.addView(view);
} else {
bottomSheet.addView(view, params);
}
// We treat the CoordinatorLayout as outside the dialog though it is technically inside
coordinator
.findViewById(R.id.touch_outside)
.setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View view) {
if (cancelable && isShowing() && shouldWindowCloseOnTouchOutside()) {
cancel();
}
}
});
// Handle accessibility events
ViewCompat.setAccessibilityDelegate(
bottomSheet,
new AccessibilityDelegateCompat() {
@Override
public void onInitializeAccessibilityNodeInfo(
View host, @NonNull AccessibilityNodeInfoCompat info) {
super.onInitializeAccessibilityNodeInfo(host, info);
if (cancelable) {
info.addAction(AccessibilityNodeInfoCompat.ACTION_DISMISS);
info.setDismissable(true);
} else {
info.setDismissable(false);
}
}
@Override
public boolean performAccessibilityAction(View host, int action, Bundle args) {
if (action == AccessibilityNodeInfoCompat.ACTION_DISMISS && cancelable) {
cancel();
return true;
}
return super.performAccessibilityAction(host, action, args);
}
});
bottomSheet.setOnTouchListener(
new View.OnTouchListener() {
@Override
public boolean onTouch(View view, MotionEvent event) {
// Consume the event and prevent it from falling through
return true;
}
});
return container;
}
/** Creates the container layout which must exist to find the behavior */
private FrameLayout ensureContainerAndBehavior() {
if (container == null) {
container =
(FrameLayout) View.inflate(getContext(), R.layout.design_bottom_sheet_dialog, null);
coordinator = (CoordinatorLayout) container.findViewById(R.id.coordinator);
bottomSheet = (FrameLayout) container.findViewById(R.id.design_bottom_sheet);
behavior = BottomSheetBehavior.from(bottomSheet);
behavior.addBottomSheetCallback(bottomSheetCallback);
behavior.setHideable(cancelable);
}
return container;
}
通过BottomSheetBehavior.from(bottomSheet);获取到BottomSheetBehavior，外部可以使用getBehavior()获取到behavior
Style 是在getThemeResId 中默认Theme_Design_Light_BottomSheetDialog
如果我们需要自定义样式BottomSheetDialog 传入你定义的Style
<style name="Theme.Design.Light.BottomSheetDialog" parent="Theme.AppCompat.Light.Dialog">
<item name="android:windowBackground">@android:color/transparent</item>
<item name="android:windowAnimationStyle">@style/Animation.Design.BottomSheetDialog</item>
<item name="bottomSheetStyle">@style/Widget.Design.BottomSheet.Modal</item>
</style>
<style name="Widget.Design.BottomSheet.Modal" parent="android:Widget">
<item name="enforceMaterialTheme">false</item>
<item name="android:background">?android:attr/colorBackground</item>
<item name="android:elevation" ns1:ignore="NewApi">
@dimen/design_bottom_sheet_modal_elevation
</item>
<item name="behavior_peekHeight">auto</item>
<item name="behavior_hideable">true</item>
<item name="behavior_skipCollapsed">false</item>
<item name="shapeAppearance">@null</item>
<item name="shapeAppearanceOverlay">@null</item>
<item name="backgroundTint">?android:attr/colorBackground</item>
</style>
设置圆角和背景
<!--BottomSheetDialog弹窗，圆角没问题-->
<style name="BottomSheetDialog" parent="Theme.Design.Light.BottomSheetDialog">
<item name="enableEdgeToEdge">true</item>
<item name="bottomSheetStyle">@style/bottomSheetStyleWrapper</item>
<item name="android:backgroundDimEnabled">false</item>
</style>
<style name="bottomSheetStyleWrapper" parent="Widget.Design.BottomSheet.Modal">
<item name="android:background">@android:color/transparent</item>
</style>
我们还发现不局是在setContentView 中进行装载的
design_bottom_sheet_dialog 源码
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">
<androidx.coordinatorlayout.widget.CoordinatorLayout
android:id="@+id/coordinator"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">
<View
android:id="@+id/touch_outside"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:focusable="false"
android:importantForAccessibility="no"
android:soundEffectsEnabled="false"
tools:ignore="UnusedAttribute"/>
<FrameLayout
android:id="@+id/design_bottom_sheet"
style="?attr/bottomSheetStyle"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal|top"
app:layout_behavior="@string/bottom_sheet_behavior"/>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
</FrameLayout>
在 design_bottom_sheet 中有一个bottomSheetStyle 对底部的FrameLayout 设置Style，
也可以看出我们可以设置design_bottom_sheet 的高度从而设置BottomSheetDialogFragment的固定高度
override fun onStart() {
super.onStart()
dialog?.window?.setDimAmount(0f) //设置布局
val h = (0.85 * resources.displayMetrics.heightPixels).toInt()
val viewRoot: FrameLayout =
dialog?.findViewById(com.google.android.material.R.id.design_bottom_sheet)!!
viewRoot.apply {
layoutParams.width = -1
layoutParams.height = h
}
}
val mDialogBehavior = BottomSheetBehavior.from(view?.parent as View) //dialog的高度
mDialogBehavior.peekHeight = h
透明Dialog设置
override fun onStart() {
super.onStart()
dialog?.window?.setDimAmount(0f)// 设置透明度
}
