Android PopupWindow does not show shadows when the elevation is set. It appears to support it from the documentation. I am using 5.0 Lollipop.
Creating the popup as follows:
popupWindow = new PopupWindow(context);
popupWindow.setOutsideTouchable(true);
popupWindow.setFocusable(true);
popupWindow.setElevation(10);
popupWindow.setContentView(rootView);
popupWindow.showAtLocation(anchorView, Gravity.NO_GRAVITY, xPos, yPos);
As answered by an Android developer.
If the inflated view doesn't have a background set, or the popup window itself doesn't have a background set (or has a transparent background) then you won't get a shadow.
which was my case and seems to be yours, since you are not using setBackgroundDrawable.
This worked for me
popupWindow.setBackgroundDrawable(new ColorDrawable(Color.WHITE));
I've opened a new issue suggesting that they update the documentation (https://code.google.com/p/android/issues/detail?id=174919)
For others who visit this answer and missed what the OP already had, you should set the elevation to create a shadow:
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
popupWindow.setElevation(20);
}
Depending on what your content view is, you might also need to set the background drawable, although this is not always necessary. If needed you can do as @Maragues suggested:
popupWindow.setBackgroundDrawable(new ColorDrawable(Color.WHITE));
To support pre-Lollipop devices you could use a 9-patch or image that includes the shadow within it.
Code
This is the code for the image above.
LayoutInflater inflater = (LayoutInflater) getSystemService(LAYOUT_INFLATER_SERVICE);
View popupView = inflater.inflate(R.layout.popup_window, null);
int width = LinearLayout.LayoutParams.WRAP_CONTENT;
int height = LinearLayout.LayoutParams.WRAP_CONTENT;
boolean focusable = true;
final PopupWindow popupWindow = new PopupWindow(popupView, width, height, focusable);
popupView.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
popupWindow.dismiss();
return true;
}
});
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
popupWindow.setElevation(20);
}
popupWindow.showAtLocation(anyView, Gravity.CENTER, 0, 0);
Note:
The elevation is in pixels when set in code, but usually in dp when set in xml. You should convert a dp value to pixels when setting it in code.
setElevationwas not showing a shadow, because my container was transparent- My container was transparent because I needed some padding on each side
- I made three containers
- Outer most container is transparent
- Next container inside has a Drawable background with the shadow
- Next container holds the actual content
- Min width of the button inside the
xmlhelps dictate the width. Same with the 2nd container's 12dp of padding.
Custom Popup Window class written in Kotlin:
class CustomPopupWindow(
private val context: Context
) : PopupWindow(context) {
init {
val view = LayoutInflater.from(context).inflate(R.layout.popup_window_layout, null)
contentView = view
height = ListPopupWindow.WRAP_CONTENT
width = ListPopupWindow.MATCH_PARENT
isOutsideTouchable = true
setTouchDismissListener()
// set the background of the second container to the drawable
// with the shadow to get our shadow
contentView.findViewById<LinearLayout>(R.id.outer_content_container).setBackgroundDrawable(context.resources.getDrawable(R.drawable.background_shadow))
}
// Add a listener to dismiss the popup Window when someone
// clicks outside of it
private fun setTouchDismissListener() {
setTouchInterceptor { _, event ->
if (event != null && event.action == MotionEvent.ACTION_OUTSIDE) {
dismiss()
return@setTouchInterceptor true
}
false
}
}
// this anchor view can be ANY view
fun show(anchor: View) {
// Remove the default background that is annoying
setBackgroundDrawable(BitmapDrawable())
// Grab the pixel count for how far down you want to put it.
// toolbar_height is 56dp for me
val yOffSetInPixels = context.resources.getDimensionPixelSize(R.dimen.toolbar_height)
// Animation to make it appear and disappear like a Dialog
animationStyle = android.R.style.Animation_Dialog
// Show it
showAtLocation(anchor, Gravity.TOP, 0, yOffSetInPixels)
}
}
- XML for Custom PopupWindow:
<?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="@android:color/transparent"
android:orientation="vertical">
<android.support.constraint.ConstraintLayout
android:id="@+id/transparent_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:background="@android:color/transparent"
android:padding="12dp">
<LinearLayout
android:id="@+id/outer_content_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/white"
android:orientation="vertical"
app:layout_constraintBottom_toBottomOf="@+id/transparent_container"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/transparent_container">
<LinearLayout
android:id="@+id/content_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="12dp">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Header" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center_vertical"
android:layout_marginTop="8dp"
android:orientation="horizontal">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:paddingEnd="0dp"
android:paddingStart="8dp"
android:text="Message" />
</LinearLayout>
<TextView
android:id="@+id/add_to_bag_button"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="16dp"
android:height="48dp"
android:background="@color/gray"
android:gravity="center"
android:minWidth="350dp"
android:text="BUTTON"
android:textAllCaps="true" />
</LinearLayout>
</LinearLayout>
</android.support.constraint.ConstraintLayout>
</LinearLayout>
- Custom Drawable that shows a shadow:
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<!-- Drop Shadow Stack -->
<item>
<shape>
<padding
android:bottom="1dp"
android:left="1dp"
android:right="1dp"
android:top="0dp" />
<solid android:color="#00CCCCCC" />
<corners android:radius="3dp" />
</shape>
</item>
<item>
<shape>
<padding
android:bottom="1dp"
android:left="1dp"
android:right="1dp"
android:top="0dp" />
<solid android:color="#10CCCCCC" />
<corners android:radius="3dp" />
</shape>
</item>
<item>
<shape>
<padding
android:bottom="1dp"
android:left="1dp"
android:right="1dp"
android:top="0dp" />
<solid android:color="#20CCCCCC" />
<corners android:radius="3dp" />
</shape>
</item>
<item>
<shape>
<padding
android:bottom="1dp"
android:left="1dp"
android:right="1dp"
android:top="0dp" />
<solid android:color="#30CCCCCC" />
<corners android:radius="3dp" />
</shape>
</item>
<item>
<shape>
<padding
android:bottom="1dp"
android:left="1dp"
android:right="1dp"
android:top="0dp" />
<solid android:color="#50CCCCCC" />
<corners android:radius="3dp" />
</shape>
</item>
<!-- Background -->
<item>
<shape>
<solid android:color="@android:color/white" />
<corners android:radius="0dp" />
</shape>
</item>
</layer-list>
- Using it all:
val popupWindow = CustomPopupWindow(activity);
popupWindow.show(anyViewInYourActivity);
来源：https://stackoverflow.com/questions/27259614/android-popupwindow-elevation-does-not-show-shadow