Android 之BottomsheetDialogFragment仿抖音评论底部弹出对话框效果(实例代码)

实现的效果图：

自定义Fragment继承BottomSheetDialogFragment
重写它的三个方法：
onCreateDialog（）
onCreateView（）
onStart（）
他们的执行顺序是从上到下

import android.app.Dialog;
import android.content.Context;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.FrameLayout;
import android.widget.ImageView;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.coordinatorlayout.widget.CoordinatorLayout;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import com.google.android.material.bottomsheet.BottomSheetBehavior;
import com.google.android.material.bottomsheet.BottomSheetDialog;
import com.google.android.material.bottomsheet.BottomSheetDialogFragment;
import java.util.ArrayList;
import java.util.List;
/**
* @Author: david.lvfujiang
* @Date: 2019/11/14
* @Describe:
*/
public class BaseFullBottomSheetFragment extends BottomSheetDialogFragment {
private List<ShareItem> mShareList = new ArrayList<>();
private int[] imgArry= {R.mipmap.five,R.mipmap.four,R.mipmap.one,R.mipmap.three};
private Context mContext;
private View view;
public static BaseFullBottomSheetFragment getInstance() {
 return new BaseFullBottomSheetFragment();
}
@NonNull
@Override
public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {
 Log.e("TAG", "onCreateDialog: ");
 //返回BottomSheetDialog的实例
return new BottomSheetDialog(this.getContext());
}
@Override
public void onStart() {
 Log.e("TAG", "onStart: ");
 super.onStart();
 //获取dialog对象
 BottomSheetDialog dialog = (BottomSheetDialog) getDialog();
 //把windowsd的默认背景颜色去掉，不然圆角显示不见
 dialog.getWindow().findViewById(R.id.design_bottom_sheet).setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
 //获取diglog的根部局
 FrameLayout bottomSheet = dialog.getDelegate().findViewById(R.id.design_bottom_sheet);
 if (bottomSheet != null) {
  //获取根部局的LayoutParams对象
  CoordinatorLayout.LayoutParams layoutParams = (CoordinatorLayout.LayoutParams) bottomSheet.getLayoutParams();
  layoutParams.height = getPeekHeight();
  //修改弹窗的最大高度，不允许上滑（默认可以上滑）
  bottomSheet.setLayoutParams(layoutParams);
final BottomSheetBehavior<FrameLayout> behavior = BottomSheetBehavior.from(bottomSheet);
  //peekHeight即弹窗的最大高度
  behavior.setPeekHeight(getPeekHeight());
  // 初始为展开状态
  behavior.setState(BottomSheetBehavior.STATE_EXPANDED);
  ImageView mReBack = view.findViewById(R.id.re_back_img);
  //设置监听
  mReBack.setOnClickListener(new View.OnClickListener() {
   @Override
   public void onClick(View view) {
    //关闭弹窗
    behavior.setState(BottomSheetBehavior.STATE_HIDDEN);
   }
  });
 }
}
/**
 * 弹窗高度，默认为屏幕高度的四分之三
 * 子类可重写该方法返回peekHeight
 *
 * @return height
 */
protected int getPeekHeight() {
 int peekHeight = getResources().getDisplayMetrics().heightPixels;
 //设置弹窗高度为屏幕高度的3/4
 return peekHeight - peekHeight / 3;
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
 mContext = getContext();
 Log.e("TAG", "onCreateView: ");
 view = inflater.inflate(R.layout.layoyt_bottomsheet, container, false);
 initData();
 initViews(view);
 return view;
}
private void initViews(View view) {
 RecyclerView recyclerView = view.findViewById(R.id.fragment_share_recyclerView);
 recyclerView.setLayoutManager(new GridLayoutManager(mContext, 3));
 RecyclerCommonAdapter adapter = new RecyclerCommonAdapter(R.layout.recyclear_item, mShareList);
 recyclerView.setAdapter(adapter);
}
private void initData() {
for (int i = 0; i < 30; i++) {
  ShareItem item = new ShareItem();
  item.setIcon(imgArry[i％4]);
  mShareList.add(item);
 }
}
}

有以下几点需要注意：

1.去掉窗口的background，窗口的background默认是白色的，如果不处理我们的根部局设置圆角背景的时候是没有效果的

dialog.getWindow().findViewById(R.id.design_bottom_sheet).setBackgroundDrawable
(new ColorDrawable
(Color.TRANSPARENT));

2.固定窗口的高度，窗口默认可以向上滑动直到铺满整个屏幕RecyclerView才开始滑动

BottomSheetDialog dialog = (BottomSheetDialog) getDialog();
 //把windowsd的默认背景颜色去掉，不然圆角显示不见
 dialog.getWindow().findViewById(R.id.design_bottom_sheet).setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
 //获取diglog的根部局
 FrameLayout bottomSheet = dialog.getDelegate().findViewById(R.id.design_bottom_sheet);
 if (bottomSheet != null) {
  //获取根部局的LayoutParams对象
  CoordinatorLayout.LayoutParams layoutParams = (CoordinatorLayout.LayoutParams) bottomSheet.getLayoutParams();
  layoutParams.height = getPeekHeight();
  //修改弹窗的最大高度，不允许上滑（默认可以上滑）
  bottomSheet.setLayoutParams(layoutParams);
final BottomSheetBehavior<FrameLayout> behavior = BottomSheetBehavior.from(bottomSheet);
  //peekHeight即弹窗的最大高度
  behavior.setPeekHeight(getPeekHeight());
  // 初始为展开状态
  behavior.setState(BottomSheetBehavior.STATE_EXPANDED);
  ImageView mReBack = view.findViewById(R.id.re_back_img);
  //设置监听
  mReBack.setOnClickListener(new View.OnClickListener() {
   @Override
   public void onClick(View view) {
    //关闭弹窗
    behavior.setState(BottomSheetBehavior.STATE_HIDDEN);
   }
  });
 }

3.Fragment加载的布局文件

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@drawable/leave_message_radiobutton_background"
android:orientation="vertical">
<RelativeLayout
 android:layout_width="match_parent"
 android:layout_height="@dimen/dp_40">
<TextView
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:layout_centerInParent="true"
  android:text="100条评论"
  android:textSize="15dp"
  android:textStyle="bold"></TextView>
<ImageView
  android:id="@+id/re_back_img"
  android:layout_width="25dp"
  android:layout_height="25dp"
  android:layout_alignParentRight="true"
  android:layout_centerVertical="true"
  android:layout_marginRight="20dp"
  android:src="@mipmap/back"></ImageView>
</RelativeLayout>
<androidx.recyclerview.widget.RecyclerView
 android:id="@+id/fragment_share_recyclerView"
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:layout_marginTop="8dp"
 android:layout_marginBottom="8dp" />
</LinearLayout>

4.Fragment布局的圆角背景

<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<!-- 填充 -->
<solid android:color="#ffffff" />
<!-- 圆角 -->
<corners android:radius="15dp" />
</shape>

5.RecyclerView的item布局

<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView 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="140dp"
android:layout_margin="8dp"
app:cardCornerRadius="8dp"
app:cardElevation="4dp">
<RelativeLayout
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:padding="8dp">
<ImageView
  android:id="@+id/img_recy_item_1_pic"
  android:layout_width="140dp"
  android:src="@mipmap/three"
  android:layout_height="match_parent"
  android:scaleType="centerCrop" />
</RelativeLayout>
</androidx.cardview.widget.CardView>

6.RecyclerView适配器是用BaseRecyclerViewAdapterHelper
Android 中RecyclerView通用适配器的实现

package com.example.bottomsheetdialogapplication;
import androidx.annotation.Nullable;
import com.chad.library.adapter.base.BaseQuickAdapter;
import com.chad.library.adapter.base.BaseViewHolder;
import java.util.List;
import java.util.Map;
/**
* @Author: david.lvfujiang
* @Date: 2019/10/30
* @Describe:
*/
public class RecyclerCommonAdapter extends BaseQuickAdapter<ShareItem, BaseViewHolder> {
public RecyclerCommonAdapter(int layoutResId, @Nullable List<ShareItem> data) {
 super(layoutResId, data);
}
@Override
protected void convert(BaseViewHolder helper, ShareItem item) {
 helper.setImageResource(R.id.img_recy_item_1_pic, item.getIcon());
 helper.addOnClickListener(R.id.img_recy_item_1_pic);
}
}

7. 调用

Button button = findViewById(R.id.on);  button.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View view) {  new BaseFullBottomSheetFragment().show(getSupportFragmentManager(), "dialog");  }  });

来源：https://blog.csdn.net/qq_39027256/article/details/103073173