Android BottomSheetDialogFragment 使用详解，设置圆角、固定高度、默认全屏

效果

MD风格的底部弹窗，比自定义dialog或popupwindow使用更简单，功能也更强大。

其实细分来说，是BottomSheet、BottomSheetDialog、BottomSheetDialogFragment

代码 https://gitee.com/zhaoyanjun/bottomSheetDialogFragmentDemo

BottomSheet
与主界面同层级关系，可以事件触发，如果有设置显示高度的话，也可以拉出来，且不会影响主界面的交互。

XML

<?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:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/white">

</LinearLayout>

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

注意，

这里需要协调布局CoordinatorLayout包裹才行
app:behavior_peekHeight 显示高度，不显示的话设置为0即可
app:layout_behavior 标示这是一个bottom_sheet
以上3个条件都是必须的。

代码

View bottomView = findViewById(R.id.ll_bottom_sheet);
bottomView.setOnClickListener(v -> {
BottomSheetBehavior behavior = BottomSheetBehavior.from(bottomView);
if (behavior.getState() == BottomSheetBehavior.STATE_EXPANDED) {
//如果是展开状态，则关闭，反之亦然
behavior.setState(BottomSheetBehavior.STATE_COLLAPSED);
} else {
behavior.setState(BottomSheetBehavior.STATE_EXPANDED);
}
});

STATE_COLLAPSED：折叠状态
STATE_EXPANDED：展开状态
STATE_DRAGGING ：过渡状态
STATE_SETTLING：视图从脱离手指自由滑动到最终停下的这一小段时间
STATE_HIDDEN ：默认无此状态（可通过app:behavior_hideable 启用此状态），启用后用户将能通过向下滑动完全隐藏 bottom sheet
BottomSheetDialog

可以看到弹出来之后是有一个半透明的蒙层的，这时候是影响主界面交互的，也就意味着此时BottomSheetDialog的优先级是要高于主界面的。

代码

public class MyBottomSheetDialog extends BottomSheetDialog {

public MyBottomSheetDialog(@NonNull Context context) {
super(context);
}

public MyBottomSheetDialog(@NonNull Context context, int theme) {
super(context, theme);
}

protected MyBottomSheetDialog(@NonNull Context context, boolean cancelable, OnCancelListener cancelListener) {
super(context, cancelable, cancelListener);
}
}

显示 Dialog

MyBottomSheetDialog bottomSheetDialog = new MyBottomSheetDialog(this);
bottomSheetDialog.setContentView(R.layout.bottom_dialog_layout);
bottomSheetDialog.show();

bottom_dialog_layout :

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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="wrap_content"
android:background="@color/white"
android:orientation="vertical">

</LinearLayout>

比较简单的使用方式，直接实例化之后setContentView，然后调用show就可以了。
这里只是一个展示效果，实际上使用场景可能会复杂一些，还要做一些操作等等，所以，也可以自定义dialog继承自BottomSheetDialog，然后处理自己的业务逻辑。

BottomSheetDialogFragment

效果跟BottomSheetDialog差不多，代码跟DialogFragment差不多。

代码

public class MyDialogFragment extends BottomSheetDialogFragment {

@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.bottom_dialog_fragment_layout, container, false);
return view;
}
}

bottom_dialog_fragment_layout

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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="wrap_content"
android:orientation="vertical"
android:background="@color/white">

</LinearLayout>

显示

MyDialogFragment dialog = new MyDialogFragment();
Bundle bundle = new Bundle();
dialog.setArguments(bundle);
dialog.show(getSupportFragmentManager(), "dialog_fragment");

但是在实际开发中，我们的需求可能并不能满足于此，比如上部分圆角效果、指定高度等

圆角效果
先设置原有背景透明

style.xml

public class MyDialogFragment extends BottomSheetDialogFragment {

@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setStyle(STYLE_NORMAL, R.style.MyBottomSheetDialog);
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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="wrap_content"
android:orientation="vertical"
android:padding="6dp"
android:background="@drawable/fragment_dialog_bg">

</LinearLayout>

特别注意：根布局除了设置 android:background 属性外，还需要设置 android:padding 属性，否则圆角显示不出来。

fragment_dialog_bg

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<corners
android:topLeftRadius="10dp"
android:topRightRadius="10dp" />
<solid android:color="@android:color/white" />

</shape>

去掉背景蒙版
需要在 style 中增加 android:backgroundDimEnabled 属性

<style name="MyBottomSheetDialog" parent="Theme.Design.Light.BottomSheetDialog">
<item name="bottomSheetStyle">@style/BottomSheetStyleWrapper</item>
<item name="android:background">@android:color/transparent</item>
<item name="android:windowBackground">@android:color/transparent</item>
<item name="android:windowNoTitle">true</item>
<item name="android:windowIsFloating">false</item>
<item name="android:backgroundDimEnabled">false</item>
</style>

设置蒙版透明度
在 style 中增加 android:backgroundDimAmount 属性，属性值范围 0 - 1 .

0 : 完全透明
1：完全不透明
<style name="MyBottomSheetDialog2" parent="Theme.Design.Light.BottomSheetDialog">
<item name="bottomSheetStyle">@style/BottomSheetStyleWrapper</item>
<item name="android:background">@android:color/transparent</item>
<item name="android:windowBackground">@android:color/transparent</item>
<item name="android:windowNoTitle">true</item>
<item name="android:windowIsFloating">false</item>
<item name="android:backgroundDimAmount">0.4</item>
</style>

点击 dialog 外部区域，dialog 不消失
重写 onCreateDialog 方法，设置 setCanceledOnTouchOutside 值为 false

public class MyDialogFragment extends BottomSheetDialogFragment {

@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setStyle(STYLE_NORMAL, R.style.MyBottomSheetDialog);
}

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
Dialog dialog = super.onCreateDialog(savedInstanceState);
dialog.setCanceledOnTouchOutside(false);
return dialog;
}

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
Dialog dialog = super.onCreateDialog(savedInstanceState);
if (dialog instanceof BottomSheetDialog) {
BottomSheetDialog bottomSheetDialog = (BottomSheetDialog) dialog;
bottomSheetDialog.setOnShowListener(dialogInterface -> {
FrameLayout bottomSheet = bottomSheetDialog.findViewById(android.support.design.R.id.design_bottom_sheet);
BottomSheetBehavior bottomSheetBehavior = BottomSheetBehavior.from(bottomSheet);
bottomSheetBehavior.setHideable(false);
});
}
return dialog;
}

设置弹框固定高度
bottomSheetBehavior.setPeekHeight(1200);
1.
使用：

@Nullab

内容铺满全屏
当内容特别多，比如有 recyclerView 时，我们希望 dialog 展开的高度是全屏的。

//默认展开
bottomSheetBehavior.setState(BottomSheetBehavior.STATE_EXPANDED);

使用

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
Dialog dialog = super.onCreateDialog(savedInstanceState);
if (dialog instanceof BottomSheetDialog) {
BottomSheetDialog bottomSheetDialog = (BottomSheetDialog) dialog;
bottomSheetDialog.setOnShowListener(dialogInterface -> {
FrameLayout bottomSheet = bottomSheetDialog.findViewById(android.support.design.R.id.design_bottom_sheet);
BottomSheetBehavior bottomSheetBehavior = BottomSheetBehavior.from(bottomSheet);
//默认展开
bottomSheetBehavior.setState(BottomSheetBehavior.STATE_EXPANDED);
});
}
return dialog;
}

监听展开收起
bottomSheetBehavior.setBottomSheetCallback()
1.
使用

public class MyDialogFragment extends BottomSheetDialogFragment {

@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setStyle(STYLE_NORMAL, R.style.MyBottomSheetDialog);
}

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
Dialog dialog = super.onCreateDialog(savedInstanceState);
if (dialog instanceof BottomSheetDialog) {
BottomSheetDialog bottomSheetDialog = (BottomSheetDialog) dialog;
bottomSheetDialog.setOnShowListener(dialogInterface -> {
FrameLayout bottomSheet = bottomSheetDialog.findViewById(android.support.design.R.id.design_bottom_sheet);
BottomSheetBehavior bottomSheetBehavior = BottomSheetBehavior.from(bottomSheet);
//默认展开
bottomSheetBehavior.setBottomSheetCallback(new BottomSheetBehavior.BottomSheetCallback() {
@Override
public void onStateChanged(@NonNull View view, int newState) {
switch (newState) {
case BottomSheetBehavior.STATE_EXPANDED:

break;
case BottomSheetBehavior.STATE_COLLAPSED:

break;
case BottomSheetBehavior.STATE_DRAGGING:

break;
case BottomSheetBehavior.STATE_SETTLING:

break;
case BottomSheetBehavior.STATE_HIDDEN:

break;
}
}

@Override
public void onSlide(@NonNull View view, float v) {

}
});
});
}
return dialog;
}