FAB BottomSheet按下后出现在屏幕上，但是位置不对(见图1)，我想做成图2的样子，怎么解决？

我的 Activity :

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() {
            @Ghi đè
            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() {
            @Ghi đè
            public void onStateChanged(@NonNull View bottomSheet, int newState) {
                // React to state change

            }

            @Ghi đè
            public void onSlide(@NonNull View bottomSheet, float slideOffset) {
                // React to dragging events
            }
        });
        mAdapterItem = new ItemAdapter(createItems(), this);
    }

    @Ghi đè
    protected void onResume() {
        super.onResume();
        RecyclerViewAdapter adapter = (RecyclerViewAdapter) mList.getAdapter();
        adapter.notifyDataSetChanged();
    }


    @Ghi đè
    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() {
            @Ghi đè
            public void onItemClick(Item item) {
                if (mBottomSheetDialog != null) {
                    mBottomSheetDialog.dismiss();
                }
            }
        }));

        mBottomSheetDialog.setContentView(view);
        mBottomSheetDialog.show();
        mBottomSheetDialog.setOnDismissListener(new DialogInterface.OnDismissListener() {
            @Ghi đè
            public void onDismiss(DialogInterface dialog) {
                mBottomSheetDialog = null;
            }
        });
    }


    @Ghi đè
    protected void onDestroy() {
        super.onDestroy();
        mAdapterItem.setListener(null);
    }

    public List createItems() {
        ArrayList 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;
    }


    @Ghi đè
    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 {

    private List mItems;
    private ItemListener mListener;

    public ItemAdapter(List items, ItemListener listener) {
        mItems = items;
        mListener = listener;
    }

    public void setListener(ItemListener listener) {
        mListener = listener;
    }

    @Ghi đè
    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));
        }

    }

    @Ghi đè
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        if (position == 0){
            ViewHolderModified holderModified = (ViewHolderModified)holder;
            holderModified.setData(mItems.get(position));
        }
        khác {
            ViewHolder viewHolder = (ViewHolder)holder;
            viewHolder.setData(mItems.get(position));
        }
    }

    @Ghi đè
    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());
        }

        @Ghi đè
        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());
        }

        @Ghi đè
        public void onClick(View v) {
            if (mListener != null) {
                mListener.onItemClick(item);
            }
        }
    }


    public interface ItemListener {
        void onItemClick(Item item);
    }

    @Ghi đè
    public int getItemViewType(int position) {
        return position;
    }
}

屏幕的xml:

    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <>
        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:id="@+id/list"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/my_toolbar" />

    <>
        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:layout_width="0dp"
        android:layout_height="0dp">

        <>
            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">

        

    

RecyclerView 中的项目:

    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">
    <>
        android:id="@+id/imageView"
        android:layout_width="40dp"
        android:layout_height="40dp"
        android:layout_margin="16dp"
        android:src="@mipmap/ic_launcher" />

    <>
        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" />

BottomSheet 的 Xml:

    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">

    <>
        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" />

图一:

图2:

câu trả lời hay nhất

我通过设置 BottomSheet 的固定高度解决了这个问题，我更改了这行代码:

mBottomSheetDialog.getWindow().setLayout(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);

到:mBottomSheetDialog.getWindow().setLayout(LinearLayout.LayoutParams.MATCH_PARENT, 700);

关于java - BottomSheet 在屏幕中的错误位置，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/38197876/