android.gesture.GestureOverlayView没有显示在图形布局上

Question

The following is part of my xml code:

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/table_detail"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="16dp"
    tools:context=".SignCheckFragment" >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical" >

        <android.gesture.GestureOverlayView
            android:id="@+id/gestureOverlayView1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="16dp" >
        </android.gesture.GestureOverlayView>          

        <TextView
            android:id="@+id/label_subtotal"
            style="?android:attr/textAppearanceMedium"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/subtotal" />

The following figure is the corresponding graphical layout. The problem is that there is no GestureOverlayView

Answer 1

I know this is an old question, but here is an answer.

The problem is that in your XML code you have the follow dimensions for the gestureOverlayView android:layout_width="match_parent" android:layout_height="wrap_content"

This means that until you specify some content the height will be 0dp, even though it will stretch all the way across the view - the width is match parent.

The way to make this appear is to add some text or some other content.

Alternatively give the GestureOverlayView some height and a background color and it should become visible.