Android-滑动以关闭背景动画的RecyclerView
据我所知,为RecyclerView实现swipe to Disclose的一种可能性是在Swipped项下实现一个背景(就像在许多google应用程序中一样),为ItemTouchHelper实现一个简单的回调,并在方法OnChildRaw中绘制背景 这是我的实现:Android-滑动以关闭背景动画的RecyclerView,android,android-recyclerview,Android,Android Recyclerview,据我所知,为RecyclerView实现swipe to Disclose的一种可能性是在Swipped项下实现一个背景(就像在许多google应用程序中一样),为ItemTouchHelper实现一个简单的回调,并在方法OnChildRaw中绘制背景 这是我的实现: ItemTouchHelper.SimpleCallback simpleItemTouchCallback = new ItemTouchHelper.SimpleCallback(0, ItemTouchHelper.RIGH
ItemTouchHelper.SimpleCallback simpleItemTouchCallback = new ItemTouchHelper.SimpleCallback(0, ItemTouchHelper.RIGHT) {
// create objects once and avoid allocating them in the onChildDraw method
Drawable background;
Drawable icon;
int iconMargin;
boolean initialized;
private void init() {
background = new ColorDrawable(Color.RED);
icon = ContextCompat.getDrawable(mAppContext, R.drawable.ic_delete_white_24dp);
iconMargin = (int) mAppContext.getResources().getDimension(R.dimen.fab_margin);
initialized = true;
}
@Override
public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
return false;
}
@Override
public void onSwiped(RecyclerView.ViewHolder viewHolder, int swipeDir) {
// remove swiped item from the list and notify the adapter
int position = viewHolder.getAdapterPosition();
mItemList.remove(position);
mRecyclerViewAdapter.notifyDataSetChanged();
}
@Override
public void onChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {
if (actionState == ItemTouchHelper.ACTION_STATE_SWIPE) {
if (dX > 0) {
View itemView = viewHolder.itemView;
// if viewHolder has been swiped away, don't do anything
if (viewHolder.getAdapterPosition() == -1) {
return;
}
if (!initialized) {
init();
}
// draw background
int dXSwipe = (int) (dX * 1.05); // increase slightly dX to avoid view flickering, compensating loss of precision due to int conversion
background.setBounds(itemView.getLeft(), itemView.getTop(),
itemView.getLeft() + dXSwipe, itemView.getBottom());
background.draw(c);
// draw icon
int top = (itemView.getTop() + itemView.getBottom() - icon.getIntrinsicHeight()) / 2;
int left = itemView.getLeft() + iconMargin;
icon.setBounds(left, top, left + icon.getIntrinsicWidth(), top + icon.getIntrinsicHeight());
icon.draw(c);
}
}
super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);
}
};
ItemTouchHelper itemTouchHelper = new ItemTouchHelper(simpleItemTouchCallback);
itemTouchHelper.attachToRecyclerView(mRecyclerView);
现在,问题是如何在下面的背景中设置视图的动画。这个动画的一个例子可以从谷歌日历中得到:当事件或提醒被滑动时,左侧的图标会根据水平位移量相应地放大
有人知道如何做到这一点吗?是否有必要采用不同的方法,可能在ViewHolder中有两个视图,一个在另一个视图上,如本文所建议的那样 我知道怎么做了 对于那些感兴趣的人来说,解决方案是使用两个视图(前景和背景)并在滑动过程中设置背景动画 布局:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout 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/item_delete_background">
<ImageView
android:id="@+id/item_delete_icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginLeft="@dimen/fab_margin"
android:layout_marginStart="@dimen/fab_margin"
app:srcCompat="@drawable/ic_delete_white_24dp" />
<android.support.constraint.ConstraintLayout
android:id="@+id/item_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/gray_bg">
<!--recyclerview item layout-->
</android.support.constraint.ConstraintLayout>
</FrameLayout>
以及ItemTouchHelper回调:
ItemTouchHelper.SimpleCallback mItemTouchCallback = new ItemTouchHelper.SimpleCallback(0, ItemTouchHelper.RIGHT) {
// override methods
public void onChildDrawOver(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder,
float dX, float dY,
int actionState, boolean isCurrentlyActive) {
// get the view which is currently swiped
ConstraintLayout itemLayout = (ConstraintLayout) ((MyViewHolder) viewHolder).getViewToSwipe();
// calculate relative horizontal displacement
// with proportion dXRelative : 1 = dX : (layoutWidth / 3)
float dXRelative = dX / itemLayout.getWidth() * 3;
// check size boundaries
if (dXRelative > 1) {
dXRelative = 1;
}
if (dXRelative < 0) {
dXRelative = 0;
}
// animate the icon with scaling on both dimensions
((MyViewHolder) viewHolder).getViewToAnimate().animate().scaleX(dXRelative).scaleY(dXRelative).setDuration(0).start();
// call draw over
getDefaultUIUtil().onDrawOver(c, recyclerView, ((MyViewHolder) viewHolder).getViewToSwipe(), dX, dY, actionState, isCurrentlyActive);
}
};
ItemTouchHelper.SimpleCallback mItemTouchCallback=新建ItemTouchHelper.SimpleCallback(0,ItemTouchHelper.RIGHT){
//重写方法
ChildRawOver上的公共空白(画布c、RecyclerView、RecyclerView、RecyclerView.ViewHolder、ViewHolder、,
浮点数dX,浮点数dY,
int actionState,布尔值为当前活动){
//获取当前已刷卡的视图
ConstraintLayout itemLayout=(ConstraintLayout)((MyViewHolder)viewHolder.getViewToSwipe();
//计算相对水平位移
//比例dX相对:1=dX:(布局宽度/3)
float dXRelative=dX/itemloayout.getWidth()*3;
//检查大小边界
如果(dXRelative>1){
dXRelative=1;
}
if(dXRelative<0){
dXRelative=0;
}
//在两个维度上使用缩放设置图标动画
((MyViewHolder)viewHolder.getViewToAnimate().animate().scaleX(dXRelative).scaleY(dXRelative).setDuration(0).start();
//取款
getDefaultUIUtil().onDrawOver(c,recyclerView,((MyViewHolder)viewHolder).getViewToSwipe(),dX,dY,actionState,isCurrentlyActive);
}
};
基本行为(视图持有者中的前台/后台)的实现是按照以下内容完成的:
希望这对某人有用
ItemTouchHelper.SimpleCallback mItemTouchCallback = new ItemTouchHelper.SimpleCallback(0, ItemTouchHelper.RIGHT) {
// override methods
public void onChildDrawOver(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder,
float dX, float dY,
int actionState, boolean isCurrentlyActive) {
// get the view which is currently swiped
ConstraintLayout itemLayout = (ConstraintLayout) ((MyViewHolder) viewHolder).getViewToSwipe();
// calculate relative horizontal displacement
// with proportion dXRelative : 1 = dX : (layoutWidth / 3)
float dXRelative = dX / itemLayout.getWidth() * 3;
// check size boundaries
if (dXRelative > 1) {
dXRelative = 1;
}
if (dXRelative < 0) {
dXRelative = 0;
}
// animate the icon with scaling on both dimensions
((MyViewHolder) viewHolder).getViewToAnimate().animate().scaleX(dXRelative).scaleY(dXRelative).setDuration(0).start();
// call draw over
getDefaultUIUtil().onDrawOver(c, recyclerView, ((MyViewHolder) viewHolder).getViewToSwipe(), dX, dY, actionState, isCurrentlyActive);
}
};