ListView 项目中的图像未填充高度

Question

在每个列表项的侧面创建一个带有 XML 可绘制对象的列表视图后，由于某种原因，图像视图没有按预期的方式显示。对于每个项目，每个列表项的顶部只出现一条小的水平线，而不是可绘制的也填满每个列表视图项的高度。为了固定图像的高度需要做什么？

drawable/ic_red.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <size android:width="20dp" />
    <solid android:color="@color/red"/>
</shape>

drawable/ic_yellow.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <size android:width="20dp" />
    <solid android:color="@color/yellow"/>
</shape>

drawable/ic_green.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <size android:width="20dp" />
    <solid android:color="@color/green"/>
</shape>

fragment_helloworld.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ListView
        android:id="@+id/list_helloworld"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

listitem_helloworld.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal" >
    <ImageView
        android:id="@+id/item_img"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:paddingStart="5dp"
        android:paddingEnd="5dp"/>

    <TextView
        android:id="@+id/item_colourtitle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:padding="10dp"
        android:layout_toEndOf="@id/item_img"/>

</RelativeLayout>

FragmentHelloWorld.java

public class FragmentHelloWorld extends android.support.v4.app.Fragment {

    public FragmentHelloWorld() {
    }

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
        View v = inflater.inflate(R.layout.fragment_helloworld, container, false);

        // Array of strings for ListView
        String[] listviewTitle = new String[]{
                "Item 1",
                "Item 2",
                "Item 3"
        };
        // Array of images for ListView
        int[] listviewImage = new int[]{
                R.drawable.ic_red,
                R.drawable.ic_yellow,
                R.drawable.ic_green
        };

        List<HashMap<String, String>> aList = new ArrayList<>();

        for (int i = 0; i < 3; i++) {
            HashMap<String, String> hm = new HashMap<>();
            hm.put("listview_title", listviewTitle[i]);
            hm.put("listview_image", Integer.toString(listviewImage[i]));
            aList.add(hm);
        }

        String[] from = {"listview_image", "listview_title"};
        int[] to = {R.id.item_img, R.id.item_colourtitle};

        SimpleAdapter simpleAdapter = new SimpleAdapter(getActivity().getBaseContext(), aList, R.layout.listitem_helloworld, from, to);
        ListView list_helloworld = (ListView) v.findViewById(R.id.list_helloworld);
        list_helloworld.setAdapter(simpleAdapter);
}

Answer 1

你可能想看看这个帖子here

或者您可以尝试为drawables指定一个矩形形状并使用LinearLayout，这很简单。