当setListAdapter扩展AppCompatActivity时，如何使用AppCompatActivity？

Question

我是android的新手，我遵循2014年的Lynda教程，使用适配器制作ListView。下面是MainActivity：

public class MainActivity extends AppCompatActivity {

    TextView output;
    ProgressBar pb;
    List<MyTask> tasks;

    List<Flower> flowerList;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        // Initialize the TextView for vertical scrolling
        output = (TextView) findViewById(R.id.textView);
        output.setMovementMethod(new ScrollingMovementMethod());

        pb = (ProgressBar) findViewById(R.id.progressBar);
        pb.setVisibility(View.INVISIBLE);

        tasks = new ArrayList<>();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (item.getItemId() == R.id.action_do_task) {
            if (isOnline()) {
                requestData("http://services.hanselandpetal.com/secure/flowers.json");
            } else {
                Toast.makeText(this, "Network isn't available", Toast.LENGTH_LONG).show();
            }
            return false;
        }
        return false;
    }

    private void requestData(String uri) {
        MyTask task = new MyTask();
        task.execute(uri);
    }

    protected void updateDisplay() {
       FlowerAdapter adapter = new FlowerAdapter(this, R.layout.item_flower, flowerList);
        setListAdapter(adapter); //<---Here is the error

    }

在setListAdapter(adapter) I get无法解决方法的错误。

我从another answer了解到，如果MainActivity扩展了ListActivity而不是AppCompatActivity，那么这个错误就解决了。但是，我得到了许多其他我无法解决的错误。所以感谢你的解决方案。

如果您需要，下面是FlowerAdapter类

public class FlowerAdapter extends ArrayAdapter<Flower> {

    private Context context;
    private List<Flower> flowerList;

    public FlowerAdapter(Context context, int resource, List<Flower> objects) {
        super(context, resource, objects);
        this.context = context;
        this.flowerList = objects;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        LayoutInflater inflater =
                (LayoutInflater) context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
        View view = inflater.inflate(R.layout.item_flower, parent, false);

        //Display flower name in the TextView widget
        Flower flower = flowerList.get(position);
        TextView tv = (TextView) view.findViewById(R.id.textView1);
        tv.setText(flower.getName());

        return view;
    }

}

下面是我在ListView中创建的content_main.xml

<ListView
    android:id="@+id/listView"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:scrollbars="vertical"
    android:text="" />

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:context="com.flowershop.myapplication.MainActivity">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/AppTheme.PopupOverlay" />

    </android.support.design.widget.AppBarLayout>

    <include
        android:id="@+id/id_content_main"
        layout="@layout/content_main" />

</android.support.design.widget.CoordinatorLayout>

Answer 1

您必须在您的ListView中创建activity_main.xml：

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

并使用它：

ListView listView = (ListView) findViewById(R.id.list);
listView.setAdapter(adapter);

试用本教程：discription&aid=65&aaid=90

或者这个：view.htm

Answer 2

您的ListView位于content_main布局中，而不是直接作为activity_main的一部分。

为content_main布局提供一个id，如下所示：

<include 
    android:id="+id/id_content_main"
    layout="@layout/content_main" />

然后像这样访问它

View contentView = findViewById(R.id.id_content_main);
listView = (ListView) contentView.findViewById(R.id.listView);
listView.setAdapter(adapter);