当有人说“我尝试遵循一些教程......”但它们不起作用时，我首先想到的是，这有点难以置信。
那将是一个更容易解决的问题。
给你一个简单的 ListView 例子：
首先，根据您的喜好创建一个资源文件：（example.xml）
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="@+id/disco_image"
android:layout_alignParentTop="true"
android:src="@drawable/ic_home"
android:layout_width="96dp"
android:layout_height="96dp"/>
<TextView
android:id="@+id/disco_title"
android:padding="12dp"
android:layout_toRightOf="@+id/disco_image"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<TextView
android:id="@+id/disco_info"
android:padding="12dp"
android:layout_toRightOf="@+id/disco_image"
android:layout_below="@+id/disco_title"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</RelativeLayout>
然后，创建一个自定义适配器，它们非常简单。现在只需扩展一个 BaseAdapter。
public class ExampleAdapter extends BaseAdapter {
//Let's create some constants first, to fill out the rows
private static final String [] DISCO_NAMES = {"Disco One", "Disco Two", "Disco Three", "Disco Four"};
private static final String [] DISCO_INFO = {"Some Info One", "Some Info Two", "Some Info Three", "Some Info Four"};
private LayoutInflater mInflater;
//Our custom adapter needs a constructor, so you can create from your activity.
public ExampleAdapter (final Context context) {
//for now, let's just get the context, we'll need it to inflate views
mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public int getCount() {
//this needs to return to the amount of rows you want to display.
//right now we return a fixed value, this could vary based on your needs
return DISCO_NAMES.length;
}
@Override
public Object getItem(int pos) {
//this is useful for knowing what item is at what position
//for now, let's just return the disco name shall we?
return DISCO_NAMES[pos];
}
@Override
public long getItemId(int pos) {
//This returns an id to the item
//personally I don't use this, so you can just return the position
return pos;
}
@Override
public View getView(int position, View view, ViewGroup viewGroup) {
//Ha, here's the important part
//ListViews reuse rows, so let's check if the view (also known as convertview) is new or being reused
if (view == null) {
//this means it's a new view, so we need to inflate it
view = mInflater.inflate(R.layout.example, null);
}
((TextView) view.findViewById(R.id.disco_title)).setText(DISCO_NAMES[position]);
((TextView) view.findViewById(R.id.disco_info)).setText(DISCO_INFO[position]);
//You can also set some images to the imageview on the layout we created earlier
return view;
}
}
然后，让我们创建一个 ListActivity 作为示例。注意ListActivit 不需要通过 setContentView 设置 Layout Resource，所以我们这里不调用它。
public class ExampleListActivity extends ListActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//create the adapter
ExampleAdapter mExampleAdapter = new ExampleAdapter(this);
//fill the listView
setListAdapter(mExampleAdapter);
}
}
这应该按原样编译，但出于性能原因，您可能需要查看 ViewHolder 模式和等等等等。显然您需要阅读更多内容，但我希望这有助于作为一个起点。