Android：ListActivity不顯示任何項目

Question

希望您能幫我解決這個問題。 我的ListActivity類將在列表中顯示ant項目

這是我的代碼：

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();
        }
    }

}

這是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>

筆記：

確保游標上有一些數據。 但是它不會顯示它們

感謝幫助

Answer 1

您錯過了對setContentView（View）的調用，該調用包含一個listview，應該使用Cursor中的數據填充該listview

Answer 2

嘗試這個：

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();
        }
    }

}

我已經將dataSource更改為ListAdapter ，還添加了startManagingCursor 。

另請參閱此處的示例

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

Answer 3

您忘記了使用對ListView的引用，但是由於擴展了ListActivity而不是Activity，因此必須按如下方式獲取對ListActivity的List的引用：

ListView lv = getListView（）;

Answer 4

我認為您需要在從xml加載的列表對象上設置適配器。 就像是：

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

其中R.id.ListViewLista是布局xml聲明內的List資源的ID（不是row.xml）