<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:background="#553b3a3a"
 android:layout_height="match_parent">
 <LinearLayout
  android:layout_width="match_parent"
  android:layout_alignParentBottom="true"
  android:orientation="vertical"
  android:id="@+id/content"
  android:background="@android:color/white"
  android:layout_height="wrap_content">
  <TextView
   android:layout_width="match_parent"
   android:textColor="#333"
   android:text="相机"
   android:padding="8dp"
   android:id="@+id/open_from_camera"
   android:gravity="center"
   android:textSize="15sp"
   android:layout_height="40dp" />
  <TextView
   android:layout_marginTop="1dp"
   android:id="@+id/open_album"
   android:layout_width="match_parent"
   android:textColor="#333"
   android:text="打开图库"
   android:padding="8dp"
   android:gravity="center"
   android:textSize="15sp"
   android:layout_height="40dp" />
  <TextView
   android:layout_marginTop="1dp"
   android:id="@+id/cancel"
   android:layout_width="match_parent"
   android:textColor="#333"
   android:text="取消"
   android:padding="8dp"
   android:gravity="center"
   android:textSize="15sp"
   android:layout_height="40dp" />
 </LinearLayout>
</RelativeLayout>

private void initPopupWindow() {
  //要在布局中显示的布局
  contentView = LayoutInflater.from(this).inflate(R.layout.popup_layout, null, false);
  //实例化PopupWindow并设置宽高
  popupWindow = new PopupWindow(contentView, LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT);
  popupWindow.setBackgroundDrawable(new BitmapDrawable());
  //点击外部消失，这里因为PopupWindow填充了整个窗口，所以这句代码就没用了
  popupWindow.setOutsideTouchable(true);
  //设置可以点击
  popupWindow.setTouchable(true);
  //进入退出的动画
  popupWindow.setAnimationStyle(R.style.MyPopWindowAnim);
 }

 private void showPopWindow() {
  View rootview = LayoutInflater.from(MainActivity.this).inflate(R.layout.activity_main, null);
  popupWindow.showAtLocation(rootview, Gravity.BOTTOM, 0, 0); 
 }

popupWindow.showAtLocation(rootview, Gravity.BOTTOM, 0, 0);

//弹出的窗口是否覆盖状态栏
 public void fitPopupWindowOverStatusBar(boolean needFullScreen) {
  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
   try {
    //利用反射重新设置mLayoutInScreen的值，当mLayoutInScreen为true时则PopupWindow覆盖全屏。
    Field mLayoutInScreen = PopupWindow.class.getDeclaredField("mLayoutInScreen");
    mLayoutInScreen.setAccessible(true);
    mLayoutInScreen.set(popupWindow, needFullScreen);
   } catch (NoSuchFieldException e) {
    e.printStackTrace();
   } catch (IllegalAccessException e) {
    e.printStackTrace();
   }
  }
 }

//设置是否遮住状态栏
  fitPopupWindowOverStatusBar(true);
  View rootview = LayoutInflater.from(MainActivity.this).inflate(R.layout.activity_main, null);
  popupWindow.showAtLocation(rootview, Gravity.BOTTOM, 0, 0);

public class DialogFromBottom extends Dialog{
 private final static int mAnimationDuration = 200;
 // 持有 ContentView，为了做动画
 private View mContentView;
 private boolean mIsAnimating = false;

 private OnBottomSheetShowListener mOnBottomSheetShowListener;

 public DialogFromBottom(@NonNull Context context) {
  super(context, R.style.AppTheme_BottomSheet);
 }
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  getWindow().getDecorView().setPadding(0, 0, 0, 0);
  // 在底部，宽度撑满
  WindowManager.LayoutParams params = getWindow().getAttributes();
  params.height = ViewGroup.LayoutParams.WRAP_CONTENT;
  params.gravity = Gravity.BOTTOM | Gravity.CENTER;//dialog从哪里弹出
  //弹出窗口的宽高
  int screenWidth = QMUIDisplayHelper.getScreenWidth(getContext());
  int screenHeight = QMUIDisplayHelper.getScreenHeight(getContext());
  params.width = screenWidth < screenHeight ? screenWidth : screenHeight;
  getWindow().setAttributes(params);
  setCanceledOnTouchOutside(true);
 }
 //设置弹出dialog中的layout
 @Override
 public void setContentView(int layoutResID) {
  mContentView = LayoutInflater.from(getContext()).inflate(layoutResID, null);
  super.setContentView(mContentView);
 }

 @Override
 public void setContentView(@NonNull View view) {
  mContentView = view;
  super.setContentView(view);
 }

 @Override
 public void setContentView(@NonNull View view, ViewGroup.LayoutParams params) {
  mContentView = view;
  super.setContentView(view, params);
 }
 /**
  * BottomSheet升起动画
  */
 private void animateUp() {
  if (mContentView == null) {
   return;
  }
  TranslateAnimation translate = new TranslateAnimation(
    Animation.RELATIVE_TO_SELF, 0f, Animation.RELATIVE_TO_SELF, 0f,
    Animation.RELATIVE_TO_SELF, 1f, Animation.RELATIVE_TO_SELF, 0f
  );
  AlphaAnimation alpha = new AlphaAnimation(0, 1);
  AnimationSet set = new AnimationSet(true);
  set.addAnimation(translate);
  set.addAnimation(alpha);
  set.setInterpolator(new DecelerateInterpolator());
  set.setDuration(mAnimationDuration);
  set.setFillAfter(true);
  mContentView.startAnimation(set);
 }

 /**
  * BottomSheet降下动画
  */
 private void animateDown() {
  if (mContentView == null) {
   return;
  }
  TranslateAnimation translate = new TranslateAnimation(
    Animation.RELATIVE_TO_SELF, 0f, Animation.RELATIVE_TO_SELF, 0f,
    Animation.RELATIVE_TO_SELF, 0f, Animation.RELATIVE_TO_SELF, 1f
  );
  AlphaAnimation alpha = new AlphaAnimation(1, 0);
  AnimationSet set = new AnimationSet(true);
  set.addAnimation(translate);
  set.addAnimation(alpha);
  set.setInterpolator(new DecelerateInterpolator());
  set.setDuration(mAnimationDuration);
  set.setFillAfter(true);
  set.setAnimationListener(new Animation.AnimationListener() {
   @Override
   public void onAnimationStart(Animation animation) {
    mIsAnimating = true;
   }

   @Override
   public void onAnimationEnd(Animation animation) {
    mIsAnimating = false;
    /**
     * Bugfix： Attempting to destroy the window while drawing!
     */
    mContentView.post(new Runnable() {
     @Override
     public void run() {
      // java.lang.IllegalArgumentException: View=com.android.internal.policy.PhoneWindow$DecorView{22dbf5b V.E...... R......D 0,0-1080,1083} not attached to window manager
      // 在dismiss的时候可能已经detach了，简单try-catch一下
      try {
       DialogFromBottom.super.dismiss();
      } catch (Exception e) {
      //这里处理异常
      }
     }
    });
   }

   @Override
   public void onAnimationRepeat(Animation animation) {

   }
  });
  mContentView.startAnimation(set);
 }

 @Override
 public void show() {
  super.show();
  animateUp();
  if (mOnBottomSheetShowListener != null) {
   mOnBottomSheetShowListener.onShow();
  }
 }

 @Override
 public void dismiss() {
  if (mIsAnimating) {
   return;
  }
  animateDown();
 }
 public interface OnBottomSheetShowListener {
  void onShow();
 }
}

@Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  getWindow().getDecorView().setPadding(0, 0, 0, 0);//把父布局的padding都设为0，目的是可以dialog撑满全屏。
  // 在底部，宽度撑满
  WindowManager.LayoutParams params = getWindow().getAttributes();
  params.height = ViewGroup.LayoutParams.WRAP_CONTENT;
  params.gravity = Gravity.BOTTOM | Gravity.CENTER;//dialog从底部弹出
  //弹出窗口的宽高，DisplayHelper.getScreenWidth(getContext());和DisplayHelper.getScreenHeight(getContext());是拿到屏幕的宽高。
  int screenWidth = DisplayHelper.getScreenWidth(getContext());
  int screenHeight = DisplayHelper.getScreenHeight(getContext());
  params.width = screenWidth < screenHeight ? screenWidth : screenHeight;//适配手机横屏
  getWindow().setAttributes(params);//重新设置dialog的属性
  setCanceledOnTouchOutside(true);//设置触摸dialog以外，dialog是否消失
 }

@Nullable
 @Override
 public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
  View view = inflater.inflate(R.layout.dialog_layout, container, false);
  return view;
 }
 @Override
 public void onStart() {
  super.onStart();
  initParams();//初始化弹窗的参数
 }
 private void initParams() {
  Window window = getDialog().getWindow();
  if (window != null) {
   WindowManager.LayoutParams lp = window.getAttributes();
   //调节灰色背景透明度[0-1]，默认0.5f
   lp.dimAmount = dimAmount;
   //是否在底部显示
   if (showBottom) {
    lp.gravity = Gravity.BOTTOM;
    if (animStyle == 0) {
     animStyle = R.style.DefaultAnimation;
    }
   }
   //设置dialog宽度
   if (width == 0) {
    lp.width = DisplayHelper.getScreenWidth(getActivity()) - 2 * DisplayHelper.dp2px(getActivity(), margin);
   } else {
    lp.width = DisplayHelper.dp2px(getActivity(), width);
   }
   //设置dialog高度
   if (height == 0) {
    lp.height = WindowManager.LayoutParams.WRAP_CONTENT;
   } else {
    lp.height = DisplayHelper.dp2px(getActivity(), height);
   }
   //设置dialog进入、退出的动画
   window.setWindowAnimations(animStyle);
   window.setAttributes(lp);
  }
  setCancelable(outCancel);//设置点击外部是否消失
 }

void showDialog() {
  FragmentTransaction ft = getFragmentManager().beginTransaction();
  // Create and show the dialog.
  DialogFragmentFromBottom newFragment = new DialogFragmentFromBottom();
  newFragment.show(ft, "dialog");
 }