如何使用addHeaderView将简单的ImageView添加到ListView

Question

我的目标很简单.我想添加一个"红矩形"作为headerview到ListView.所以我创建了一个简单的活动

public class MainActivity extends Activity {
    private String[] adapterData = new String[] { "Afghanistan", "Albania", "Algeria", 
            "American Samoa", "Andorra", "Angola"}; 

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ListView lv;
        lv = (ListView)findViewById(R.id.list);

        LayoutInflater lf;
        View headerView;
        lf = this.getLayoutInflater();
        headerView = (View)lf.inflate(R.layout.header, null, false);

        lv.addHeaderView(headerView, null, false);

        lv.setAdapter(new ArrayAdapter<String>(this, R.layout.list_item, adapterData)); 
    }
}

activity_main.xml中

<ListView xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="#FF0" 
        android:cacheColorHint="#0000"
        android:paddingLeft="20dip"
        android:paddingRight="20dip"
        android:divider="#0000"
        android:scrollbarStyle="outsideOverlay" />

list_item.xml

<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@android:id/text1"
    android:layout_width="match_parent"
    android:layout_height="0dip"
    android:minHeight="40dip"
    android:singleLine="true"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:gravity="center_vertical"
/>

最重要的是header.xml

<?xml version="1.0" encoding="utf-8"?>
<ImageView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="100dip"
    android:background="#F00"/>

但它似乎没有用.没有显示任何内容.

可以对此提出一些建议吗？非常感谢您的帮助.

Answer 1

老问题,但我只是复制它并运行它,确实红色没有出现.

你遗漏了一件简单的事情:无论你怎么称呼inflate你总是¹必须传递父视图(第二个参数),以便它可以找出LayoutParams要实例化的子类.
¹:总有^1个例外

.inflate(R.layout.header,lv,false)

关于这个问题的更多信息,我强烈建议:http://www.doubleencore.com/2013/05/layout-inflation-as-intended/(值得一读甚至几次)

您的完整代码已修改(xml文件可以保持原样):

public class MainActivity extends Activity {
    private static final String[] ADAPTER_DATA = {
            "Afghanistan", "Albania", "Algeria", "American Samoa", "Andorra", "Angola"
    };

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ListView list = (ListView) findViewById(R.id.list);
        View header = getLayoutInflater().inflate(R.layout.header, list, false);

        list.addHeaderView(header, null, false);
        list.setAdapter(new ArrayAdapter<String>(this, R.layout.list_item, ADAPTER_DATA));
    }
}

Answer 2

这是我添加标题的方式:

    View view = View.inflate(context, R.layout.header, null);
    lv = (ListView) findViewById(R.id.list);


    lv.addHeaderView(view);