GridView：放大布局后未显示ImageViews / ImageButtons

Question

I try to display tiles within a GridView using a custom item layout. Each has a TextView as well as three image buttons below. The XML item layout looks like this. Within the Android Studio designer, the layout looks exactly the way I want it.

<?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="match_parent"
    android:layout_weight="1"
    android:orientation="vertical">

    <TextView
        android:id="@+id/textView3"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="TextView" />

    <LinearLayout
        android:layout_weight="1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <ImageView
            android:id="@+id/imageView3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            app:srcCompat="@drawable/ic_edit" />

        <ImageView
            android:id="@+id/imageView2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            app:srcCompat="@drawable/ic_play" />

        <ImageView
            android:id="@+id/imageView4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            app:srcCompat="@drawable/ic_remove" />
    </LinearLayout>
</LinearLayout>

However, after inflating within my GridView adapter, the TextView is visible but the three image views are not shown. Same happens when I use image button. Curiously, when I replace the three images by a normal button, it works.

Adapter code:

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    final LayoutInflater inflater = LayoutInflater.from(context);
    View v = inflater.inflate(R.layout.layout_subject, parent, false);
    float scale = context.getResources().getDisplayMetrics().density;
    v.setLayoutParams(new ConstraintLayout.LayoutParams((int)(180 * scale + .5f), (int)(180 * scale + .5f)));

    return v;
}

The defined tile size 180 x 180 is indeed large enough, at runtime, there's plenty of empty space where the images should be.

Any idea what could be wrong?

Thank you in advance

Answer 1

The image assets you are using are vectors and you need to make some changes in your build.gradle file. add

 vectorDrawables.useSupportLibrary = true

under defaultConfig in your build.gradle file.

android {
  defaultConfig {
     ...
     ... 
     vectorDrawables.useSupportLibrary = true  //add this
   }
}

In your Activity add this line of code

 AppCompatDelegate.setCompatVectorFromResourcesEnabled(true);

now you can set vector using app:srcCompat instead of android:src .