我有一个RecyclerView
,它显示列表项。当用户单击它们时,这些项目会展开。显示动画效果很好,但是每次单击某个项目时,RecyclerView
似乎都将一个项目添加到了最高位置,但随后将其隐藏起来,使其向下滚动,如下面的GIF中所示。
我的列表项布局:
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingTop="16dp"
android:paddingStart="16dp"
android:paddingEnd="16dp"
android:paddingBottom="8dp"
app:layout_constraintBottom_toBottomOf="@+id/txv_item_history_bill_type"
app:layout_constraintTop_toBottomOf="@+id/txv_item_history_bill_type">
<ImageView
android:id="@+id/imv_item_history_category"
android:layout_width="40dp"
android:layout_height="40dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"/>
<TextView
android:id="@+id/txv_item_history_bill_type"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:fontFamily="sans-serif"
android:letterSpacing="0.15"
android:textAllCaps="true"
app:layout_constraintStart_toEndOf="@+id/imv_item_history_category"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/txv_item_history_description"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:fontFamily="sans-serif"
android:letterSpacing="0"
android:textAllCaps="false"
android:textColor="@color/colorAccentTextColor"
android:textSize="24sp"
app:layout_constraintStart_toEndOf="@+id/imv_item_history_category"
app:layout_constraintTop_toBottomOf="@+id/txv_item_history_bill_type" />
<TextView
android:id="@+id/txv_item_history_date_amount"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:fontFamily="sans-serif-medium"
android:letterSpacing="0.1"
android:textAllCaps="false"
android:textSize="14sp"
app:layout_constraintStart_toEndOf="@+id/imv_item_history_category"
app:layout_constraintTop_toBottomOf="@+id/txv_item_history_description" />
</android.support.constraint.ConstraintLayout>
<HorizontalScrollView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="72dp"
android:scrollbars="none">
<LinearLayout
android:id="@+id/ll_item_history_bill_action_buttons_container"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:visibility="gone">
<android.support.design.button.MaterialButton
android:id="@+id/btn_item_history_edit"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:text="@string/btn_edit"
style="@style/Widget.MaterialComponents.Button.OutlinedButton" />
<android.support.design.button.MaterialButton
android:id="@+id/btn_item_history_delete"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:text="@string/btn_delete" />
<android.support.design.button.MaterialButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:text="@string/btn_edit_amount"
style="@style/Widget.MaterialComponents.Button.TextButton"/>
<android.support.design.button.MaterialButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:text="@string/btn_edit_description"
style="@style/Widget.MaterialComponents.Button.TextButton"/>
<android.support.design.button.MaterialButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/btn_change_category"
style="@style/Widget.MaterialComponents.Button.TextButton"/>
</LinearLayout>
</HorizontalScrollView>
<View
android:id="@+id/view_item_history_divider"
android:layout_width="match_parent"
android:layout_height="1dp"
android:layout_marginTop="8dp"
android:layout_marginStart="72dp"
android:background="@color/colorDivider" />
有效代码:
final boolean isExpanded = position == mExpandedPosition;
holder.mLlBillActionButtonsContainer.setVisibility(isExpanded ? View.VISIBLE : View.GONE);
holder.itemView.setActivated(isExpanded);
holder.itemView.setOnClickListener(v -> {
mExpandedPosition = isExpanded ? -1 : position;
TransitionManager.beginDelayedTransition(recyclerView);
notifyDataSetChanged();
});
答案 0 :(得分:0)
我相信这是由于代码中这两行的结合而发生的:
TransitionManager.beginDelayedTransition(recyclerView); notifyDataSetChanged();
RecyclerView默认情况下支持动画,只要您使用更具体的“通知”方法(例如notifyItemChanged()
)而不是notifyDataSetChanged()
。因此,如果可以改用它们,则可以删除TransitionManager
调用。
好消息是,您知道之前“扩展”了哪个职位,因此可以仅在旧职位和新职位上致电notifyItemChanged()
。这样可以使您获得更好的动画效果。
这是为您更新的侦听器:
holder.itemView.setOnClickListener(v -> {
int previousExpandedPosition = mExpandedPosition;
mExpandedPosition = isExpanded ? -1 : position;
if (previousExpandedPosition != -1) {
notifyItemChanged(previousExpandedPosition);
}
if (mExpandedPosition != -1) {
notifyItemChanged(mExpandedPosition);
}
});