Question

我希望你帮我解决这个问题。我的ListActivity类woudlnt在列表中显示ant项目

这是我的代码：

import android.os.Bundle;
import android.provider.BaseColumns;
import android.app.Activity;
import android.app.ListActivity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.CursorAdapter;
import android.widget.EditText;
import android.widget.SimpleCursorAdapter;
import android.support.v4.app.NavUtils;

public class Sale2 extends ListActivity {
    private static final int DIALOG_ID = 100;

    private SQLiteDatabase database;

    DBAdapter db;

    private CursorAdapter dataSource;

    private View entryView;

    private EditText firstNameEditor;

    private EditText lastNameEditor;

    private static final String fields[] = { "_id", "_date", "_soldPrice" };

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        try {
            db = new DBAdapter(this);
            db.open();
            Cursor data = db.getAllSales2();
            System.out.println("after getallsales2");
            dataSource = new SimpleCursorAdapter(this, R.layout.row, data,
                    fields, new int[] { R.id._id, R.id.first, R.id.last });
            System.out.println("after simplecursoradapter"
                    + dataSource.toString());

            setListAdapter(dataSource);
            System.out.println("setListAdapter");
        } catch (Exception e) {
            Log.e("ERROR", "ERROR IN CODE: " + e.toString());
            e.printStackTrace();
        }
    }

}

这是row.xml

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

    <TextView
        android:id="@+id/_id"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/first"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/last"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

注意：

我确定光标上有一些数据。但它不会显示它们

感谢帮助

Answer 1

你缺少对setContentView（View）的调用，它包含一个listview，应该使用Cursor中的数据填充

Answer 2

试试这个：

public class Sale2 extends ListActivity {
    private static final int DIALOG_ID = 100;

    private SQLiteDatabase database;

    DBAdapter db;

    private ListAdapter dataSource;

    private View entryView;

    private EditText firstNameEditor;

    private EditText lastNameEditor;

    private static final String fields[] = { "_id", "_date", "_soldPrice" };

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        try {
            db = new DBAdapter(this);
            db.open();
            Cursor data = db.getAllSales2();
            System.out.println("after getallsales2");
            startManagingCursor(data);
            dataSource = new SimpleCursorAdapter(this, R.layout.row, data,
                    fields, new int[] { R.id._id, R.id.first, R.id.last });
            System.out.println("after simplecursoradapter"
                    + dataSource.toString());

            setListAdapter(dataSource);
            System.out.println("setListAdapter");
        } catch (Exception e) {
            Log.e("ERROR", "ERROR IN CODE: " + e.toString());
            e.printStackTrace();
        }
    }

}

我已将dataSource更改为ListAdapter并添加了startManagingCursor。

另见这里的例子

http://developer.android.com/reference/android/app/ListActivity.html

Answer 3

您忘记使用对ListView的引用，但由于您已扩展ListActivity而不是Activity，因此您必须获得对ListActivity列表的引用，如下所示：

ListView lv = getListView（）;

Answer 4

我认为您需要在从xml加载的列表对象上设置适配器。类似的东西：

listaNodiView = (ListView) findViewById(R.id.ListViewLista);
listaNodiView.setListAdapter(dataSource);

其中R.id.ListViewLista是布局xml声明（NOT row.xml）中List资源的id

Android：ListActivity不显示任何Item

4 个答案: