Java holder.position=位置; } @凌驾 public int getItemCount(){ 返回listOfUsableApis.size(); } @凌驾 公共长getItemId(int位置){ 返回长。值(位置); } 公共类设置ViewHolder扩展了RecyclerView.ViewHolder{ 公共职位; 公共文本视图文本视图; 公共设置ViewHolder(文本视图v){ 超级(五); textView=v; } } } 私有类设置DetailsLookup扩展ItemDetailsLookup{ @可空 @凌驾 public ItemDetails getItemDetails(@NonNull MotionEvent事件){ View-View=settingsRecyclerView.findChildViewUnder(event.getX(),event.getY()); 如果(视图!=null){ final RecyclerView.ViewHolder ViewHolder=设置RecyclerView.getChildViewHolder(视图); if(设置的视图持有者实例适配器。设置视图持有者){ 最终设置Adapter.SettingViewHolder SettingViewHolder=(SettingsAdapter.SettingViewHolder)viewHolder; 返回新的ItemDetailsLookup.ItemDetails(){ @凌驾 public int getPosition(){ 返回viewHolder.getAdapterPosition(); } @可空 @凌驾 公共长getSelectionKey(){ 返回Long.valueOf(设置ViewHolder.position); } }; } } 返回null; } } }
布局Java holder.position=位置; } @凌驾 public int getItemCount(){ 返回listOfUsableApis.size(); } @凌驾 公共长getItemId(int位置){ 返回长。值(位置); } 公共类设置ViewHolder扩展了RecyclerView.ViewHolder{ 公共职位; 公共文本视图文本视图; 公共设置ViewHolder(文本视图v){ 超级(五); textView=v; } } } 私有类设置DetailsLookup扩展ItemDetailsLookup{ @可空 @凌驾 public ItemDetails getItemDetails(@NonNull MotionEvent事件){ View-View=settingsRecyclerView.findChildViewUnder(event.getX(),event.getY()); 如果(视图!=null){ final RecyclerView.ViewHolder ViewHolder=设置RecyclerView.getChildViewHolder(视图); if(设置的视图持有者实例适配器。设置视图持有者){ 最终设置Adapter.SettingViewHolder SettingViewHolder=(SettingsAdapter.SettingViewHolder)viewHolder; 返回新的ItemDetailsLookup.ItemDetails(){ @凌驾 public int getPosition(){ 返回viewHolder.getAdapterPosition(); } @可空 @凌驾 公共长getSelectionKey(){ 返回Long.valueOf(设置ViewHolder.position); } }; } } 返回null; } } },java,android,kotlin,Java,Android,Kotlin,布局 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="fill_parent" android:layout_height="fill_parent" android:baselineAligned="false"
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:baselineAligned="false"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#454545"
android:weightSum="100">
<Button
android:id="@+id/settings_back_button"
android:background="#454545"
android:drawableStart="@drawable/arrow_white"
android:drawableLeft="@drawable/arrow_white"
android:layout_gravity="start"
android:layout_width="@dimen/ll_mdu_10"
android:layout_height="@dimen/ll_mdu_10"
android:layout_weight="5"/>
<Space
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="90"
/>
<Button
android:id="@+id/settings_apply_button"
android:background="#454545"
android:drawableStart="@android:drawable/ic_menu_save"
android:drawableLeft="@android:drawable/ic_menu_save"
android:layout_gravity="end"
android:layout_width="@dimen/ll_mdu_10"
android:layout_height="@dimen/ll_mdu_10"
android:layout_weight="5"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingBottom="@dimen/activity_vertical_margin">
<TextView
android:id="@+id/textView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Long-press for first setting, then tap other settings for multiple selection"
app:layout_constraintBottom_toTopOf="@+id/settingsRecyclerView"
app:layout_constraintTop_toTopOf="parent" />
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/settingsRecyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintTop_toBottomOf="@+id/textView" />
</LinearLayout>
</LinearLayout>
这个文档很难阅读。它需要一个例子
难以理解的Kotlin示例
Google IO介绍此功能(但在Kotlin中)
另一个Java示例
您应该试试这个:谢谢@ArjunVyas在本例中,我主要是问如何具体实现SelectionTracker,而不是启用列表项选择的其他方法。
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:baselineAligned="false"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#454545"
android:weightSum="100">
<Button
android:id="@+id/settings_back_button"
android:background="#454545"
android:drawableStart="@drawable/arrow_white"
android:drawableLeft="@drawable/arrow_white"
android:layout_gravity="start"
android:layout_width="@dimen/ll_mdu_10"
android:layout_height="@dimen/ll_mdu_10"
android:layout_weight="5"/>
<Space
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="90"
/>
<Button
android:id="@+id/settings_apply_button"
android:background="#454545"
android:drawableStart="@android:drawable/ic_menu_save"
android:drawableLeft="@android:drawable/ic_menu_save"
android:layout_gravity="end"
android:layout_width="@dimen/ll_mdu_10"
android:layout_height="@dimen/ll_mdu_10"
android:layout_weight="5"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingBottom="@dimen/activity_vertical_margin">
<TextView
android:id="@+id/textView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Long-press for first setting, then tap other settings for multiple selection"
app:layout_constraintBottom_toTopOf="@+id/settingsRecyclerView"
app:layout_constraintTop_toTopOf="parent" />
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/settingsRecyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintTop_toBottomOf="@+id/textView" />
</LinearLayout>
</LinearLayout>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/setting_list_item_text_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@drawable/setting_background"
android:gravity="center_vertical"
android:minHeight="?android:attr/listPreferredItemHeightSmall"
android:paddingStart="?android:attr/listPreferredItemPaddingStart"
android:paddingEnd="?android:attr/listPreferredItemPaddingEnd"
android:textAppearance="?android:attr/textAppearanceListItemSmall" />
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="@android:color/holo_green_dark" android:state_activated="true" />
<item android:drawable="@android:color/white" />
</selector>