Question

我开始使用Android，并将此课程列为成分列表。每个成分都有复选框和添加按钮。我希望将此数据传输到本地数据库，但不确定如何进行此操作。我需要数据库帮助程序类吗？请给我一些代码示例或如何在我的onclick方法中实现它。以下是我的代码......

Tab2Activity.java

public class Tab2Activity extends Fragment {

public ArrayList<String> shoppingList;
public ArrayList<CheckBox> checkboxes;

// public CheckBox cb;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.tab_two, container, false);

    shoppingList = new ArrayList<String>();
    checkboxes = new ArrayList<CheckBox>();

    LinearLayout l = (LinearLayout)inflater.inflate(R.layout.tab_two, container, false);
   // RelativeLayout s = (RelativeLayout)inflater.inflate(R.layout.tab_two, container, false);
   // RelativeLayout r = (RelativeLayout)s.findViewById(R.layout.text);

    Bundle b = getArguments();
    String ingredientsString = b.getString("ingredients");

    System.out.println("string: " + ingredientsString);
    String[] ingredients = ingredientsString.split(",");

    System.out.println("size: " + ingredients.length);

    ScrollView sv = new ScrollView(getActivity());
    LinearLayout ll = new LinearLayout(getActivity());
    ll.setOrientation(LinearLayout.VERTICAL);
    sv.addView(ll);

    for(int i = 0; i <ingredients.length; i++) {
        final CheckBox cb = new CheckBox(getActivity());
        cb.setText(ingredients[i]);
        cb.setTag("checkbox" + i);
        cb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                if (isChecked) {
                    buttonView.getTag();
                    shoppingList.add(cb.getText().toString());
                    System.out.println("ADDING: " + cb.getText().toString());
                } else {
                    shoppingList.remove(cb.getText().toString());
                    System.out.println("REMOVING: " + cb.getText().toString());
                }

            }
        });
        ll.addView(cb);
    }
    Button button = new Button(getActivity());
    button.setText("Add to list");
    button.setPadding(0, 10, 0, 10);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            String list = "";

            for (int x=0; x<shoppingList.size(); x++)
                list += shoppingList.get(x) + "\n";

            new AlertDialog.Builder(getActivity())
                    .setIcon(android.R.drawable.ic_dialog_alert)
                    .setTitle("Save List")
                    .setMessage("Add following items to list?\n\n" + list)
                    .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {

                        }

                    })
                    .setNegativeButton("No", null)
                    .show();

        }
    });
    ll.addView(button);
    l.addView(sv);
    return l;

   // return v;
}

}

更新：我做了一个数据库课......你觉得我走在正确的轨道上吗？

public class DBhelper extends SQLiteOpenHelper {
private static final String DATABASE_NAME = "Ingredients_DB";
private static final int DATABASE_VERSION = 2;
private static final String TABLE_NAME = "INGREDIENTS";
public static final String Col_1 = "TITLE";

public DBhelper(Context context) {

    super(context, DATABASE_NAME, null, 2);
    SQLiteDatabase db = this.getWritableDatabase();

}

@Override
public void onCreate(SQLiteDatabase db) {
    db.execSQL("create table" + TABLE_NAME + "(TITLE STRING PRIMARY KEY AUTOINCREMENT, TITLE TEXT");
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    db.execSQL("DROP TABLE IF EXISTS" + TABLE_NAME);
    onCreate(db);
}

public boolean insertData(String Title) {
    SQLiteDatabase db = this.getWritableDatabase();
    ContentValues contentValues = new ContentValues();
    contentValues.put(Col_1, Title);
    long result = db.insert(TABLE_NAME, null, contentValues);

    if(result == -1){
        return false;
    }
    else
        return true;
}

}

Answer 1

有几个options。将其存储在本地数据库中可能是也可能不是最好的方法。无论哪种方式，官方文档都可以指导您如何使用以下任何选项：

共享首选项 - 将私有原始数据存储在键值对中。
内部存储 - 将私人数据存储在设备内存中。
外部存储 - 将公共数据存储在共享外部存储上。
SQLite数据库 - 将结构化数据存储在私有数据库中。
网络连接 - 使用您自己的网络服务器在网络上存储数据。

请参阅Android documentation "Storage Options"了解如何实施适合您情况的最佳方案。

将数据添加到数据库Android

1 个答案: