安卓PopupWindow elevation未显示阴影

Question

设置了标高后，Android PopupWindow不会显示阴影。从文档中看，它似乎支持它。我使用的是5.0版的棒棒糖。

如下所示创建弹出窗口：

    popupWindow = new PopupWindow(context);
    popupWindow.setOutsideTouchable(true);
    popupWindow.setFocusable(true);
    popupWindow.setElevation(10);
    popupWindow.setContentView(rootView);
    popupWindow.showAtLocation(anchorView, Gravity.NO_GRAVITY, xPos, yPos);

Answer 1

作为answered by an Android developer。

如果放大的视图没有背景设置，或者弹出窗口本身没有背景设置(或者有透明的背景)，那么你就得不到阴影。

这是我的情况，似乎也是你的情况，因为你没有使用setBackgroundDrawable。

这对我很有效

popupWindow.setBackgroundDrawable(new ColorDrawable(Color.WHITE));

我已经打开了一个新的问题，建议他们更新文档(https://code.google.com/p/android/issues/detail?id=174919)

Answer 2

对于访问此答案并错过OP已有内容的其他人，您应该设置高程以创建阴影：

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
    popupWindow.setElevation(20);
}

​

​

根据您的内容视图，您可能还需要将背景设置为可绘制，尽管这并不总是必要的。如果需要，你可以按照@Maragues建议的那样做：

popupWindow.setBackgroundDrawable(new ColorDrawable(Color.WHITE));

为了支持之前的棒棒糖设备，你可以使用包含阴影的9补丁或图像。

代码

这是上图的代码。

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);

注意：

在代码中设置时，标高以像素为单位，但在xml中设置时，通常以dp为单位。在代码中设置DP值时，应将其转换为像素。

Answer 3

• setElevation没有显示阴影，因为我的容器是透明的，我的容器是透明的，因为我需要在每一面上都有一些填充

Screenshot of the below code

Next容器我做了三个containers

• Outer，最大的容器是transparent

• Next容器里面有一个可绘制的背景与阴影

• 下一个容器持有实际的内容

• 最小宽度的按钮里面的xml帮助规定宽度。与第二个容器的12dp填充相同。

用Kotlin编写的自定义弹出窗口类：

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)
  }
}

用于自定义PopupWindow:的

• XML

<?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>

显示阴影的

• 自定义绘图：

<?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>

使用它的

• ：

val popupWindow = CustomPopupWindow(activity);
popupWindow.show(anyViewInYourActivity);