AndroidBottomSheetDialog详解

Posted 2022-12-08 寒小枫

1.简介

BottomSheetDialog是一个自定义的从底部滑入的对话框。市面上很多App都有类似的效果，今天我们实现如下效果：

2.页面布局

从底部弹出view的效果是BottomSheetBehavior来实现的。view必须支持嵌套滚动，而且必须是CoordinatorLayout的直接子类，来看下主题布局。

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/activity_bottom_sheet"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    app:behavior_hideable="true"
    >

    <!--Toolbar-->
    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/ThemeOverlay.AppCompat.Light">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />
    </android.support.design.widget.AppBarLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@+id/tab_layout"
        android:gravity="center"
        android:orientation="vertical"
        app:behavior_hideable="true"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"
        >
        <Button
            android:text="显示"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="20dp"
            android:id="@+id/btn_show"
            />

        <Button
            android:text="底部按钮"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="20dp"
            android:id="@+id/btn_bottom" />
    </LinearLayout>

    <!--底部弹出框-->
    <LinearLayout
        android:id="@+id/tab_layout"
        android:layout_width="match_parent"
        android:layout_height="?actionBarSize"
        android:layout_alignParentBottom="true"
        android:background="@android:color/holo_purple"
        app:behavior_hideable="true"
        app:behavior_peekHeight="0dp"
        app:layout_behavior="@string/bottom_sheet_behavior">

        <Button
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="首页" />

        <Button
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="课程" />

        <Button
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="我的" />

    </LinearLayout>

</android.support.design.widget.CoordinatorLayout>

3.点击按钮弹出BottomSheetDialog

创建BottomSheetDialog以及相关的初始化：

        WindowManager wm = this.getWindowManager();
        int height = wm.getDefaultDisplay().getHeight();

        //构造函数的第二个参数可以设置BottomSheetDialog的主题样式
//        mBottomSheetDialog = new BottomSheetDialog(this,R.style.MyBottomDialog);
        mBottomSheetDialog = new BottomSheetDialog(this);
        //导入底部reycler布局
        View view = LayoutInflater.from(this).inflate(R.layout.recycler_view, null, false);
        mBottomSheetDialog.setContentView(view);

        BottomSheetBehavior mBehavior = BottomSheetBehavior.from((View) view.getParent());
        //设置默认弹出高度为屏幕的0.4倍
        mBehavior.setPeekHeight((int) (0.4 * height));

        //设置点击dialog外部不消失
        mBottomSheetDialog.setCanceledOnTouchOutside(false);

        //RecyclerView相关设置
        RecyclerView recyclerView = (RecyclerView) view.findViewById(R.id.recyclerView);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        recyclerView.setAdapter(new MyRecyclerAdapter(this));

点击按钮后，控制显示和隐藏：

if (!mBottomSheetDialog.isShowing()) 
     mBottomSheetDialog.show();
 else 
     mBottomSheetDialog.dismiss();

此时点击按钮，如下效果：

问题：此时再次点击显示按钮的话，不会弹出底部框，屏幕会变暗，这是之前我们划下收缩隐藏BottomSheetDialog后，bottomSheetDialogBehavior的状态为隐藏，再次show之后，系统未恢复bottomSheetDialogBehavior的状态，还是隐藏，所以再次点击后页面只是变暗，可以在隐藏时通过设置BottomSheetDialog的状态来解决：

final BottomSheetBehavior bottomSheetBehavior = BottomSheetBehavior.from(view);
bottomSheetBehavior.setState(BottomSheetBehavior.STATE_COLLAPSED);

4.弹出普通的View

我们点击显示底部按钮时弹出如下界面：

看下布局文件，CoordinatorLayout里放了一个LinearLayout：

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/activity_bottom_sheet"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    app:behavior_hideable="true"
    >
    <!--底部弹出框-->
    <LinearLayout
        android:id="@+id/tab_layout"
        android:layout_width="match_parent"
        android:layout_height="?actionBarSize"
        android:layout_alignParentBottom="true"
        android:background="@android:color/holo_purple"
        app:behavior_hideable="true"
        app:behavior_peekHeight="0dp"
        app:layout_behavior="@string/bottom_sheet_behavior">

        <Button
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="首页" />

        <Button
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="课程" />

        <Button
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="我的" />

    </LinearLayout>

</android.support.design.widget.CoordinatorLayout>

通过设置LinearLayout的app:layout_behavior属性来设置此布局的行为,设置后Linear会在屏幕的底部：

app:layout_behavior="@string/bottom_sheet_behavior"

控制显示和隐藏：

// 拿到这个tab_layout对应的BottomSheetBehavior
mBottomSheetBehavior = BottomSheetBehavior.from(findViewById(R.id.tab_layout));
// 控制展开还是关闭
if (mBottomSheetBehavior.getState() == BottomSheetBehavior.STATE_EXPANDED) 
    mBottomSheetBehavior.setState(BottomSheetBehavior.STATE_COLLAPSED);
 else if (mBottomSheetBehavior.getState() == BottomSheetBehavior.STATE_COLLAPSED) 
    mBottomSheetBehavior.setState(BottomSheetBehavior.STATE_EXPANDED);

5.解决弹出dialog后Android5.0+status bar变黑

自定义BottomSheetDialog,屏幕高度减去状态栏的高度即可：

public class MyBottomSheetDialog extends BottomSheetDialog

    private Activity activity;

    public MyBottomSheetDialog(@NonNull Context context,Activity activity) 
        super(context);
        this.activity = activity;
    

    public MyBottomSheetDialog(@NonNull Context context, @StyleRes int theme,Activity activity) 
        super(context, theme);
        this.activity = activity;
    

    protected MyBottomSheetDialog(@NonNull Context context, boolean cancelable, OnCancelListener cancelListener,Activity activity) 
        super(context, cancelable, cancelListener);
        this.activity = activity;
    

    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        int screenHeight = getScreenHeight(activity);
        int statusBarHeight = getStatusBarHeight(getContext());
        int dialogHeight = screenHeight - statusBarHeight;
        getWindow().setLayout(ViewGroup.LayoutParams.MATCH_PARENT, dialogHeight == 0 ? ViewGroup.LayoutParams.MATCH_PARENT : dialogHeight);
    

    private static int getScreenHeight(Activity activity) 
        DisplayMetrics displaymetrics = new DisplayMetrics();
        activity.getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
        return displaymetrics.heightPixels;
    

    private static int getStatusBarHeight(Context context) 
        int statusBarHeight = 0;
        Resources res = context.getResources();
        int resourceId = res.getIdentifier("status_bar_height", "dimen", "android");
        if (resourceId > 0) 
            statusBarHeight = res.getDimensionPixelSize(resourceId);
        
        return statusBarHeight;
    

参考：

1.http://blog.csdn.net/maosidiaoxian/article/details/52288597

2.http://blog.csdn.net/yanzhenjie1003/article/details/51938425

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