java - 通过CUSTOM listview显示SQLite信息

Question

我有一个可用的 sqlite 数据库，可以将项目添加到其中并通过 ListView 查看。我现在想动态地向每个 View 添加一个编辑/删除按钮。

按照教程 http://looksok.wordpress.com/2012/11/03/android-custom-listview-tutorial/我创建了一个带有编辑/删除按钮的自定义 XML 文件。然而，我无法按照该教程进行操作，因为它没有显示用于检索和显示 sqlite 信息。

自定义 ListView 的 XML 布局:

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

    <EditText
        android:id="@+id/itemName"
        android:layout_width="0sp"
        android:layout_height="fill_parent"
        android:layout_weight="2"
        android:gravity="center_vertical"
        android:hint="@string/title"
        android:textAppearance="?android:attr/textAppearanceSmall" />

    <EditText
        android:id="@+id/itemQuantity"
        android:layout_width="0sp"
        android:layout_height="fill_parent"
        android:layout_weight="1"
        android:gravity="center"
        android:inputType="numberDecimal"
        android:text="@string/quantity"
        android:textAppearance="?android:attr/textAppearanceSmall" />

    <ImageButton
        android:id="@+id/editItem"
        android:layout_width="@dimen/width_button"
        android:layout_height="fill_parent"
        android:contentDescription="@string/app_name"
        android:onClick="editOnClick"
        android:src="@android:drawable/ic_menu_edit" />
    
    <ImageButton
        android:id="@+id/deleteItem"
        android:layout_width="@dimen/width_button"
        android:layout_height="fill_parent"
        android:contentDescription="@string/app_name"
        android:onClick="removeOnClick"
        android:src="@android:drawable/ic_menu_delete" />
</LinearLayout>

当前库存 XML(显示 ListView 的位置):

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/currentInventory"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    xmlns:tools="http://schemas.android.com/tools" >

    <TextView android:layout_marginTop="5dip"
        android:id="@+id/selectCat"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/selectCategory"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <Spinner
        android:id="@+id/categoryChoose"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:entries="@array/catergory_arrays" />
    
    
    <ListView
        android:id="@+id/customDbListView"
        android:layout_width="match_parent"
        android:layout_height="350dip"
        android:layout_marginBottom="20dip"
        android:layout_marginTop="20dip"
        tools:listitem="@layout/list_view_custom" >

    </ListView>

    <Button
        android:id="@+id/scanCurrent"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:layout_marginBottom="5dip"
        android:text="@string/scan" />

    <Button
        android:id="@+id/editItemCurrent"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:layout_marginBottom="5dp"
        android:text="@string/editItem" />

</LinearLayout>

创建数据库:

package com.example.fooditemmonitor;

import java.util.ArrayList;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

public final class ItemDatabase {

    // the Activity or Application that is creating an object from this class.
    Context context;

    // a reference to the database used by this application/object
    private SQLiteDatabase db;

    // These constants are specific to the database.
    private final String DATABASE_NAME = "ItemDatabase.sqlite";
    private final int DATABASE_VERSION = 7;

    // These constants are specific to the database table.
    private final String TABLE_NAME = "foodItems";
    private final String COLUMN_NAME_ENTRY_ID = "entryid";
    private final String COLUMN_NAME_BARCODE = "barcode";
    private final String COLUMN_NAME_TITLE = "title";
    private final String COLUMN_NAME_QUANTITY = "quantity";
    private final String COLUMN_NAME_DATE = "date";
    private final String COLUMN_NAME_CATEGORY = "category";
    String SQL_DELETE_ENTRIES = "DROP TABLE IF EXISTS " + TABLE_NAME;
    String SQL_CREATE_TABLE = "create table " + TABLE_NAME + " ("
            + COLUMN_NAME_ENTRY_ID
            + " integer primary key autoincrement not null," + COLUMN_NAME_DATE
            + " date," + COLUMN_NAME_BARCODE + " text," + COLUMN_NAME_TITLE
            + " text," + COLUMN_NAME_QUANTITY + " int," + COLUMN_NAME_CATEGORY
            + " text" + ");";

    public ItemDatabase(Context context) {
        this.context = context;

        // create or open the database
        ItemDatabaseHelper helper = new ItemDatabaseHelper(context);
        this.db = helper.getWritableDatabase();
    }

    public void addRow(String rowStringOne, String rowStringTwo,
            String rowStringThree, String rowStringFour, int rowIntFive) {
        // this is a key value pair holder used by android's SQLite functions
        ContentValues values = new ContentValues();
        values.put(COLUMN_NAME_DATE, rowStringOne);
        values.put(COLUMN_NAME_BARCODE, rowStringTwo);
        values.put(COLUMN_NAME_TITLE, rowStringThree);
        values.put(COLUMN_NAME_CATEGORY, rowStringFour);
        values.put(COLUMN_NAME_QUANTITY, rowIntFive);

        // ask the database object to insert the new data
        try {
            db.insert(TABLE_NAME, null, values);
        } catch (Exception e) {
            Log.e("DB ERROR", e.toString());
            e.printStackTrace();
        }
    }

    public void updateRow(long rowID, String rowStringOne, String rowStringTwo,
            String rowStringThree, int rowIntFour) {
        // this is a key value pair holder used by android's SQLite functions
        ContentValues values = new ContentValues();
        values.put(COLUMN_NAME_DATE, rowStringOne);
        values.put(COLUMN_NAME_BARCODE, rowStringTwo);
        values.put(COLUMN_NAME_TITLE, rowStringThree);
        values.put(COLUMN_NAME_QUANTITY, rowIntFour);

        // ask the database object to update the database row of given rowID
        try {
            db.update(TABLE_NAME, values, COLUMN_NAME_ENTRY_ID + "=" + rowID,
                    null);
        } catch (Exception e) {
            Log.e("DB Error", e.toString());
            e.printStackTrace();
        }
    }

    public void deleteRow(long rowID) {
        // ask the database manager to delete the row of given id
        try {
            db.delete(TABLE_NAME, COLUMN_NAME_ENTRY_ID + "=" + rowID, null);
            getAllRowsAsArrays();
        } catch (Exception e) {
            Log.e("DB ERROR", e.toString());
            e.printStackTrace();
        }
    }

    public ArrayList<ArrayList<Object>> getCategoryOfArrays(String category) {
        // create an ArrayList that will hold all of the data collected from
        // the database.
        ArrayList<ArrayList<Object>> dataArrays = new ArrayList<ArrayList<Object>>();
        // this is a database call that creates a "cursor" object.
        // the cursor object store the information collected from the
        // database and is used to iterate through the data.
        Cursor cursor;

        try {
            // ask the database object to create the cursor.

            cursor = db.query(TABLE_NAME, new String[] { COLUMN_NAME_DATE,
                    COLUMN_NAME_TITLE, COLUMN_NAME_QUANTITY,
                    COLUMN_NAME_CATEGORY }, COLUMN_NAME_CATEGORY + "='"
                    + category + "'", null, null, null, COLUMN_NAME_TITLE
                    + " ASC");

            // move the cursor's pointer to position zero.
            cursor.moveToFirst();

            // if there is data after the current cursor position, add it to the
            // ArrayList.
            if (!cursor.isAfterLast()) {
                do {

                    ArrayList<Object> dataList = new ArrayList<Object>();

                    dataList.add(cursor.getString(cursor
                            .getColumnIndex(COLUMN_NAME_DATE)));
                    dataList.add(cursor.getString(cursor
                            .getColumnIndex(COLUMN_NAME_TITLE)));
                    dataList.add(cursor.getInt(cursor
                            .getColumnIndex(COLUMN_NAME_QUANTITY)));

                    dataArrays.add(dataList);
                } while (cursor.moveToNext());
            }

            // let java know that you are through with the cursor.
            cursor.close();
        } catch (SQLException e) {
            Log.e("DB Error", e.toString());
            e.printStackTrace();
        }
        // return the ArrayList that holds the data collected from the database.
        return dataArrays;
    }

    public ArrayList<ArrayList<Object>> getAllRowsAsArrays() {
        // create an ArrayList that will hold all of the data collected from
        // the database.
        ArrayList<ArrayList<Object>> dataArrays = new ArrayList<ArrayList<Object>>();
        // this is a database call that creates a "cursor" object.
        // the cursor object store the information collected from the
        // database and is used to iterate through the data.
        Cursor cursor;

        try {
            // ask the database object to create the cursor.

            cursor = db.query(TABLE_NAME, new String[] { COLUMN_NAME_TITLE,
                    COLUMN_NAME_QUANTITY, COLUMN_NAME_CATEGORY }, null, null,
                    null, null, COLUMN_NAME_TITLE + " ASC");

            // move the cursor's pointer to position zero.
            cursor.moveToFirst();

            // if there is data after the current cursor position, add it to the
            // ArrayList.
            if (!cursor.isAfterLast()) {
                do {
                    ArrayList<Object> dataList = new ArrayList<Object>();

                    dataList.add(cursor.getString(cursor
                            .getColumnIndex(COLUMN_NAME_TITLE)));
                    dataList.add(cursor.getInt(cursor
                            .getColumnIndex(COLUMN_NAME_QUANTITY)));

                    dataArrays.add(dataList);
                } while (cursor.moveToNext());
            }

            // let java know that you are through with the cursor.
            cursor.close();

        } catch (SQLException e) {
            Log.e("DB Error", e.toString());
            e.printStackTrace();
        }
        // return the ArrayList that holds the data collected from the database.
        return dataArrays;
    }

    public class ItemDatabaseHelper extends SQLiteOpenHelper {
        public ItemDatabaseHelper(Context context) {
            super(context, DATABASE_NAME, null, DATABASE_VERSION);
        }

        public void onCreate(SQLiteDatabase db) {
            // execute the query string to the database.
            db.execSQL(SQL_CREATE_TABLE);
        }

        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            // This database is only a cache for online data, so its upgrade
            // policy is to simply to discard the data and start over
            db.execSQL(SQL_DELETE_ENTRIES);
            onCreate(db);
        }
    }
}

显示数据库数据的当前代码:

package com.example.fooditemmonitor;

import java.util.ArrayList;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Spinner;

public class CurrentItems extends Activity {

    ItemDatabase db;
    Context context;
    Button addButton, editButton;
    ListView listView;
    int spinnerID;

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

        db = new ItemDatabase(this);

        // create references and listeners for the GUI interface
        setupViews();

        // make the buttons clicks perform actions
        addButtonListeners();

        // display search results
        displaySearch();

    }

    private void setupViews() {
        // bring up current database items
        listView = (ListView) findViewById(R.id.customDbListView);

        // THE BUTTONS
        addButton = (Button) findViewById(R.id.scanCurrent);
        editButton = (Button) findViewById(R.id.editItemCurrent);
    }

    private void addButtonListeners() {

        Spinner selectCat = (Spinner) findViewById(R.id.categoryChoose);
        selectCat
                .setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
                    public void onItemSelected(AdapterView<?> parent,
                            View view, int pos, long id) {
                        displaySearch();
                    }

                    public void onNothingSelected(AdapterView<?> parent) {
                        // Do nothing
                    }
                });

        addButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(CurrentItems.this, AddItem.class));

            }
        });

        editButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(CurrentItems.this, EditItems.class));

            }
        });
    }

    public int getSelectedItemPosition() {
        Spinner selectCat = (Spinner) findViewById(R.id.categoryChoose);
        spinnerID = selectCat.getSelectedItemPosition();
        return spinnerID;
    }

    private void displaySearch() {
        // TODO Auto-generated method stub
        Spinner selectCat = (Spinner) findViewById(R.id.categoryChoose);
        spinnerID = selectCat.getSelectedItemPosition();
        String catSelected;
        final ArrayList<String> items = new ArrayList<String>();
        final ArrayAdapter<String> itemArray;
        itemArray = new ArrayAdapter<String>(this,
                android.R.layout.simple_list_item_1, items);

        {
            if (getSelectedItemPosition() == 0) {
                ArrayList<ArrayList<Object>> data = db.getAllRowsAsArrays();
                for (int position = 0; position < data.size(); position++) {
                    ArrayList<Object> row = data.get(position);
                    items.add("\nTitle:  " + row.get(0).toString()
                            + "\nQuantity:  " + row.get(1).toString() + "\n");
                    itemArray.notifyDataSetChanged();
                }
                listView.setAdapter(itemArray);
            } else if (getSelectedItemPosition() == 1) {
                catSelected = "Fridge";
                ArrayList<ArrayList<Object>> data = db
                        .getCategoryOfArrays(catSelected);
                for (int position = 0; position < data.size(); position++) {
                    ArrayList<Object> row = data.get(position);
                    items.add("\nDate:  " + row.get(0).toString()
                            + "\nTitle:  " + row.get(1).toString()
                            + "\nQuantity:  "
                            + Integer.parseInt(row.get(2).toString()) + "\n");
                    itemArray.notifyDataSetChanged();
                }
                listView.setAdapter(itemArray);
            } else if (getSelectedItemPosition() == 2) {
                catSelected = "Can";
                ArrayList<ArrayList<Object>> data = db
                        .getCategoryOfArrays(catSelected);
                for (int position = 0; position < data.size(); position++) {
                    ArrayList<Object> row = data.get(position);
                    items.add("\nDate:  " + row.get(0).toString()
                            + "\nTitle:  " + row.get(1).toString()
                            + "\nQuantity:  "
                            + Integer.parseInt(row.get(2).toString()) + "\n");
                    itemArray.notifyDataSetChanged();
                }
                listView.setAdapter(itemArray);
            } else if (getSelectedItemPosition() == 3) {
                catSelected = "Fruit";
                ArrayList<ArrayList<Object>> data = db
                        .getCategoryOfArrays(catSelected);
                for (int position = 0; position < data.size(); position++) {
                    ArrayList<Object> row = data.get(position);
                    items.add("\nDate:  " + row.get(0).toString()
                            + "\nTitle:  " + row.get(1).toString()
                            + "\nQuantity:  "
                            + Integer.parseInt(row.get(2).toString()) + "\n");
                    itemArray.notifyDataSetChanged();
                }
                listView.setAdapter(itemArray);
            } else if (getSelectedItemPosition() == 4) {
                catSelected = "Vegetable";
                ArrayList<ArrayList<Object>> data = db
                        .getCategoryOfArrays(catSelected);
                for (int position = 0; position < data.size(); position++) {
                    ArrayList<Object> row = data.get(position);
                    items.add("\nDate:  " + row.get(0).toString()
                            + "\nTitle:  " + row.get(1).toString()
                            + "\nQuantity:  "
                            + Integer.parseInt(row.get(2).toString()) + "\n");
                    itemArray.notifyDataSetChanged();
                }
                listView.setAdapter(itemArray);
            } else {
                ArrayList<ArrayList<Object>> data = db.getAllRowsAsArrays();
                for (int position = 0; position < data.size(); position++) {
                    ArrayList<Object> row = data.get(position);
                    items.add("\nTitle:  " + row.get(0).toString()
                            + "\nQuantity:  " + row.get(1).toString() + "\n");
                    itemArray.notifyDataSetChanged();
                }

            }
        }
    }

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

当前代码仅将数据显示为常规 ListView 。我需要数据显示为:

标题数量(编辑按钮)(删除按钮)

所有帮助将不胜感激!谢谢

Answer 1

由于我有点无聊，我冒昧地实现了适配器。由于您没有发布相应的类表示，因此您必须编辑从数据库检索元素的方式以及访问类信息的方式。

但是，您可以实现 CursorAdapter 而不是 BaseAdapter。

public class QuantatiyAdapter extends BaseAdapter {

    private Context context;
    private List<Item> data;

    public QuantatiyAdapter(Context context) {
        this.context = context;
        //TODO actually put all your data into that list.
        this.data = Database.getAllData();
    }

    @Override
    public int getCount() {
        return this.data.size();
    }

    @Override
    public Object getItem(int arg0) {
        return this.data.get(arg0);
    }

    @Override
    public long getItemId(int arg0) {
        return 0;
    }

    @Override
    public View getView(int position, View converView, ViewGroup container) {

        ViewHolder holder = null;

        if (converView == null) {
            converView = LayoutInflater.from(context).inflate(R.layout.cutomLayout, null);
            holder = new ViewHolder();
            holder.title = (TextView) converView.findViewById(R.id.itemName);
            holder.quantity = (TextView) converView.findViewById(R.id.itemQuantity);
            holder.edit = (ImageButton) converView.findViewById(R.id.editItem);
            holder.delete = (ImageButton) converView.findViewById(R.id.deleteItem);
            converView.setTag(holder);
        } else {
            holder = (ViewHolder) converView.getTag();
        }

        // filling text
        holder.title.setText(getItem(position).getTitle());


        // adding action listeners to buttons
        holder.edit.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO fill methods for buttons

            }
        });


        return converView;
    }

    private static class ViewHolder {
        TextView title,quantity;
        ImageButton edit,delete;
    }

}