//使用BottomSheetDialog方式实现底部弹窗
    void showBottomSheetDialog(){
        BottomSheetDialog bottomSheet = new BottomSheetDialog(this);//实例化BottomSheetDialog
        bottomSheet.setCancelable(true);//设置点击外部是否可以取消
        bottomSheet.setContentView(R.layout.dialog_layout);//设置对框框中的布局
        bottomSheet.show();//显示弹窗
    }

    //设置需要展示的view
    @Override
    public void setContentView(@LayoutRes int layoutResId) {
        super.setContentView(wrapInBottomSheet(layoutResId, null, null));
    }
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Window window = getWindow();
        if (window != null) {
            if (Build.VERSION.SDK_INT >= 21) {
                //设置5.0以上系统状态栏
                window.clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
                window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
            }
            //设置布局的属性
            window.setLayout(ViewGroup.LayoutParams.MATCH_PARENT,
                    ViewGroup.LayoutParams.MATCH_PARENT);
        }
    }

 private View wrapInBottomSheet(int layoutResId, View view, ViewGroup.LayoutParams params) {
        final FrameLayout container = (FrameLayout) View.inflate(getContext(),
                R.layout.design_bottom_sheet_dialog, null);
        final CoordinatorLayout coordinator =
                (CoordinatorLayout) container.findViewById(R.id.coordinator);
        if (layoutResId != 0 && view == null) {
            view = getLayoutInflater().inflate(layoutResId, coordinator, false);
        }
        FrameLayout bottomSheet = (FrameLayout) coordinator.findViewById(R.id.design_bottom_sheet);//这个view就是放置我们自己布局的容器
        mBehavior = BottomSheetBehavior.from(bottomSheet);
        mBehavior.setBottomSheetCallback(mBottomSheetCallback);
        mBehavior.setHideable(mCancelable);
        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 (mCancelable && isShowing() && shouldWindowCloseOnTouchOutside()) {
                    cancel();
                }
            }
        });
        //此处省略部分代码
        ......
        return container;
    }

<?xml version="1.0" encoding="utf-8"?>
<!--
  ~ Copyright (C) 2015 The Android Open Source Project
  ~
  ~ Licensed under the Apache License, Version 2.0 (the "License");
  ~ you may not use this file except in compliance with the License.
  ~ You may obtain a copy of the License at
  ~
  ~      http://www.apache.org/licenses/LICENSE-2.0
  ~
  ~ Unless required by applicable law or agreed to in writing, software
  ~ distributed under the License is distributed on an "AS IS" BASIS,
  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  ~ See the License for the specific language governing permissions and
  ~ limitations under the License.
-->
<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">
    <android.support.design.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: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"
            android:clickable="true"
            app:layout_behavior="@string/bottom_sheet_behavior"/>
    </android.support.design.widget.CoordinatorLayout>
</FrameLayout>