FAB BottomSheet 按下后出现在屏幕上，但位置不对（见图1），我想按图2 那样。如何解决？
我的活动：
public class FirstscreenActivity extends AppCompatActivity implements RecyclerItemClickListener.OnItemClickListener,
ItemAdapter.ItemListener {
private BottomSheetDialog mBottomSheetDialog;
BottomSheetBehavior behavior;
private ItemAdapter mAdapterItem;
private FloatingActionButton floatButton;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.front);
floatButton = (FloatingActionButton) findViewById(R.id.float_button);
floatButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
showBottomSheetDialog();
mBottomSheetDialog.getWindow().setLayout(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
mBottomSheetDialog.getWindow().setGravity(Gravity.BOTTOM);
}
});
View bottomSheet = findViewById(R.id.bottom_sheet);
behavior = BottomSheetBehavior.from(bottomSheet);
behavior.setBottomSheetCallback(new BottomSheetBehavior.BottomSheetCallback() {
@Override
public void onStateChanged(@NonNull View bottomSheet, int newState) {
// React to state change
}
@Override
public void onSlide(@NonNull View bottomSheet, float slideOffset) {
// React to dragging events
}
});
mAdapterItem = new ItemAdapter(createItems(), this);
}
@Override
protected void onResume() {
super.onResume();
RecyclerViewAdapter adapter = (RecyclerViewAdapter) mList.getAdapter();
adapter.notifyDataSetChanged();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu, menu);
return super.onPrepareOptionsMenu(menu);
}
private void showBottomSheetDialog() {
if (behavior.getState() == BottomSheetBehavior.STATE_EXPANDED) {
behavior.setState(BottomSheetBehavior.STATE_COLLAPSED);
}
mBottomSheetDialog = new BottomSheetDialog(this);
View view = getLayoutInflater().inflate(R.layout.sheet, null);
RecyclerView recyclerView = (RecyclerView) view.findViewById(R.id.recyclerView);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setAdapter(new ItemAdapter(createItems(), new ItemAdapter.ItemListener() {
@Override
public void onItemClick(Item item) {
if (mBottomSheetDialog != null) {
mBottomSheetDialog.dismiss();
}
}
}));
mBottomSheetDialog.setContentView(view);
mBottomSheetDialog.show();
mBottomSheetDialog.setOnDismissListener(new DialogInterface.OnDismissListener() {
@Override
public void onDismiss(DialogInterface dialog) {
mBottomSheetDialog = null;
}
});
}
@Override
protected void onDestroy() {
super.onDestroy();
mAdapterItem.setListener(null);
}
public List<Item> createItems() {
ArrayList<Item> items = new ArrayList<>();
items.add(new Item("Add new record"));
items.add(new Item(R.drawable.camera, "from new shoots"));
items.add(new Item(R.drawable.folder_multiple_image, "from ready images"));
return items;
}
@Override
public void onItemClick(Item item) {
behavior.setState(BottomSheetBehavior.STATE_COLLAPSED);
}
}
RecyclerView的适配器代码，在BottomSheet中：
public class ItemAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private List<Item> mItems;
private ItemListener mListener;
public ItemAdapter(List<Item> items, ItemListener listener) {
mItems = items;
mListener = listener;
}
public void setListener(ItemListener listener) {
mListener = listener;
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
switch (viewType) {
case 0:
return new ViewHolderModified(LayoutInflater.from(parent.getContext())
.inflate(R.layout.bottom_title, parent, false));
default:
return new ViewHolder(LayoutInflater.from(parent.getContext())
.inflate(R.layout.item, parent, false));
}
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
if (position == 0){
ViewHolderModified holderModified = (ViewHolderModified)holder;
holderModified.setData(mItems.get(position));
}
else {
ViewHolder viewHolder = (ViewHolder)holder;
viewHolder.setData(mItems.get(position));
}
}
@Override
public int getItemCount() {
return mItems.size();
}
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
public ImageView imageView;
public TextView textView;
public Item item;
public ViewHolder(View itemView) {
super(itemView);
itemView.setOnClickListener(this);
imageView = (ImageView) itemView.findViewById(R.id.imageView);
textView = (TextView) itemView.findViewById(R.id.textView);
}
public void setData(Item item) {
this.item = item;
imageView.setImageResource(item.getDrawableResource());
textView.setText(item.getTitle());
}
@Override
public void onClick(View v) {
if (mListener != null) {
mListener.onItemClick(item);
}
}
}
public class ViewHolderModified extends RecyclerView.ViewHolder implements View.OnClickListener {
public TextView textView;
public Item item;
public ViewHolderModified(View itemView) {
super(itemView);
itemView.setOnClickListener(this);
textView = (TextView) itemView.findViewById(R.id.titleView);
}
public void setData(Item item) {
this.item = item;
textView.setText(item.getTitle());
}
@Override
public void onClick(View v) {
if (mListener != null) {
mListener.onItemClick(item);
}
}
}
public interface ItemListener {
void onItemClick(Item item);
}
@Override
public int getItemViewType(int position) {
return position;
}
}
屏幕的xml：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.v7.widget.Toolbar
android:id="@+id/my_toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#118b0a"
android:elevation="4dp"
android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />
<android.support.v7.widget.RecyclerView
android:id="@+id/list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/my_toolbar" />
<android.support.design.widget.FloatingActionButton
android:id="@+id/float_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentEnd="true"
android:layout_alignParentRight="true"
android:layout_margin="16dp"
android:src="@drawable/add_white"
app:backgroundTint="@color/red"
/>
<android.support.design.widget.CoordinatorLayout
android:layout_width="0dp"
android:layout_height="0dp">
<LinearLayout
android:id="@+id/bottom_sheet"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#fff"
android:gravity="bottom"
android:orientation="vertical"
app:layout_behavior="@string/bottom_sheet_behavior">
</LinearLayout>
</android.support.design.widget.CoordinatorLayout>
</RelativeLayout>
RecyclerView 中的项目：
<?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="wrap_content"
android:background="?android:attr/selectableItemBackground"
android:clickable="true"
android:gravity="center_vertical"
android:orientation="horizontal">
<ImageView
android:id="@+id/imageView"
android:layout_width="40dp"
android:layout_height="40dp"
android:layout_margin="16dp"
android:src="@mipmap/ic_launcher" />
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="16dp"
android:layout_marginStart="16dp"
android:textColor="@color/black"
android:gravity="center_vertical"
android:textSize="22sp" />
</LinearLayout>
BottomSheet 的 Xml：
<?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="wrap_content"
android:background="?android:attr/selectableItemBackground"
android:clickable="true"
android:gravity="center_vertical"
android:orientation="horizontal">
<TextView
android:id="@+id/titleView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="16dp"
android:layout_marginStart="16dp"
android:gravity="center_vertical"
android:textColor="#787878"
android:textSize="20sp" />
</LinearLayout>
图片1：
图二：
