问题
What is the proper way to expand a CardView?
回答1:
Use an expandable list view with cardview
or even
You can use wrap content as height of cardview and use textview inside it below title, so on click make the textview visible and vice-versa.
but isn't it bad design ?
nope it isn't if you give some transition or animation when it's expanded or collapsed
If you want to see some default transition then just write android:animateLayoutChanges="true" in parent layout.
回答2:
If you are using CardViews inside a ListView or RecyclerView see my answer for recommended way of doing it: RecyclerView expand/collapse items
If you are just using CardView the do this in your on onClickListener of cardview:
TransitionManager.beginDelayedTransition(cardview);
detailsView.setVisibility(View.VISIBLE);
By default keep the visibility of your detailsView to be GONE in your xml.
回答3:
I used a cardview and an expand section item_description in the cardview. For the expand part I created a TextView below the header section (LinearLayout/item_description_layout) and when the user clicks on the header layout an expand/collapse method is called. Here is the code in the cardview:
<LinearLayout
android:id="@+id/item_description_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:minHeight="48dp"
android:paddingStart="16dp"
android:paddingEnd="16dp"
android:orientation="horizontal">
<TextView
android:id="@+id/item_description_title"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="0.9"
android:gravity="center_vertical"
android:text="@string/description"/>
<ImageView
android:id="@+id/item_description_img"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="0.1"
android:layout_gravity="center_vertical|end"
app:srcCompat="@drawable/ic_expand_more_black_24dp"/>
</LinearLayout>
<TextView
android:id="@+id/item_description"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingStart="16dp"
android:paddingEnd="16dp"
android:paddingBottom="16dp"
android:gravity="center_vertical"
android:visibility="gone"
tools:text="description goes here"/>
Here is the method that is called. I also added a ObjectAnimator to handle the expand/collapse animation of the block. This is a simple animation that uses the length of the description text.
void collapseExpandTextView() {
if (mItemDescription.getVisibility() == View.GONE) {
// it's collapsed - expand it
mItemDescription.setVisibility(View.VISIBLE);
mDescriptionImg.setImageResource(R.drawable.ic_expand_less_black_24dp);
} else {
// it's expanded - collapse it
mItemDescription.setVisibility(View.GONE);
mDescriptionImg.setImageResource(R.drawable.ic_expand_more_black_24dp);
}
ObjectAnimator animation = ObjectAnimator.ofInt(mItemDescription, "maxLines", mItemDescription.getMaxLines());
animation.setDuration(200).start();
}
回答4:
just a line of code before setting visibility GONE/ VISIBLE can do:
TransitionManager.beginDelayedTransition([the rootView containing the cardView], new AutoTransition());
no need to use the animateLayoutChanges=true in XML (this way also simple, but collapse behaviour is bad)
回答5:
I got the solution ( single cardview expandable listview ) check this link http://www.devexchanges.info/2016/08/expandingcollapsing-recyclerview-row_18.html
if you add down arrow icon you just use my code
create xml
<RelativeLayout
android:id="@+id/layout_expand"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingTop="10dp"
android:paddingBottom="10dp"
android:paddingLeft="10dp"
android:orientation="vertical">
<TextView
android:id="@+id/item_description_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@color/white"
android:clickable="true"
android:onClick="toggle_contents"
android:padding="10dp"
android:text="Guest Conditions"
android:textColor="@color/hint_txt_color"
android:fontFamily="sans-serif-medium"
android:textStyle="normal"
android:paddingBottom="15dp"
android:textSize="16dp"/>
<ImageView
android:layout_alignParentRight="true"
android:paddingTop="4dp"
android:paddingRight="10dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/ic_keyboard_arrow_down"/>
<!--content to hide/show -->
<TextView
android:id="@+id/item_description"
android:layout_below="@+id/item_description_title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/white"
android:padding="10dp"
android:text="@string/about_txt2"
android:textColor="@color/hint_txt_color"
android:fontFamily="sans-serif-medium"
android:textStyle="normal"
android:paddingBottom="15dp"
android:visibility="gone"
android:textSize="12dp" />
</RelativeLayout>
</android.support.v7.widget.CardView>
///////////////////////////////////////////////
Mainactivity.java
RelativeLayout layout_expand = (RelativeLayoutfindViewById(R.id.layout_expand);
item_description = (TextView) findViewById(R.id.item_description);
TextView item_description_title;
item_description_title = (TextView) findViewById(R.id.item_description_title);
item_description.setVisibility(View.GONE);
///////////////////////////////////////////////////////////////////
animationUp = AnimationUtils.loadAnimation(getApplicationContext(), R.anim.slide_up);
animationDown = AnimationUtils.loadAnimation(getApplicationContext(), R.anim.slide_down);
layout_expand.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(item_description.isShown()){
item_description.setVisibility(View.GONE);
item_description.startAnimation(animationUp);
}
else{
item_description.setVisibility(View.VISIBLE);
item_description.startAnimation(animationDown);
}
}
});
item_description_title.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(item_description.isShown()){
item_description.setVisibility(View.GONE);
item_description.startAnimation(animationUp);
}
else{
item_description.setVisibility(View.VISIBLE);
item_description.startAnimation(animationDown);
}
}
});
回答6:
mView.Click +=(sender, e) =>{
LinearLayout temp = mView.FindViewById<LinearLayout>(Resource.Id.LinerCart);
if (vs == false) {
temp.Visibility = ViewStates.Gone;
vs = true;
} else {
temp.Visibility = ViewStates.Visible;
vs = false;
}
};
来源：https://stackoverflow.com/questions/35500322/expand-and-collapse-cardview