SQLite数据库使用

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1、对话框的添加

为之前的应用添加对话框

需要完成的任务：

1）创建DatePickerFragment

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    
    return new AlertDialog.Builder(getActivity())
            .setView(v)
            .setTitle(R.string.date_picker_title)
            .setPositiveButton(android.R.string.ok,null)
            .create();
}

2）借助FragmentManager显示对话框

要传递crime给DatePickerFragment需要新建一个

newInstance(Date)方法：

public class DatePickerFragment extends DialogFragment {

private static final String ARG_DATE = "date";
private DatePicker mDatePicker;
public static DatePickerFragment newInstance(Date date) {

    Bundle args = new Bundle();
    args.putSerializable(ARG_DATE, date);

    DatePickerFragment fragment = new DatePickerFragment();
    fragment.setArguments(args);
    return fragment;
}

同时在string.xml中添加字符串：

<string name="date_picker_title">Date of crime:</string>

对话框的响应：

public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode != Activity.RESULT_OK) {
        return;
    }

    if (requestCode == REQUEST_DATE) {
        Date date = (Date) data
                .getSerializableExtra(DatePickerFragment.EXTRA_DATE);
        mCrime.setDate(date);
        updateCrime();
        updateDate();
    }

2、工具栏及菜单

1）生成图标：

右键单击drawable目录，选择new→Image Asset 如图

 点击next 进入预览画面：

2）响应菜单项选择

需在CrimeListFragment中

实现onOptionsItemSelected(MenuItem)方法    

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case R.id.new_crime:
            Crime crime = new Crime();
            CrimeLab.get(getActivity()).addCrime(crime);
            updateUI();
            mCallbacks.onCrimeSelected(crime);
            return true;
        default:
            return super.onOptionsItemSelected(item);
    }
}

在CrimeListFragment中

响应SHOWSUBTITLE菜单项单击事件

case R.id.show_subtitle:
    mSubtitleVisible = !mSubtitleVisible;
    getActivity().invalidateOptionsMenu();
    updateSubtitle();
    return true;

3、SQLite数据库

1）创建初始数据库

创建CrimeBaseHelper类，代码如下：  

public class CrimeBaseHelper extends SQLiteOpenHelper {
    private static final int VERSION = 1;
    private static final String DATABASE_NAME = "crimeBase.db";
    public CrimeBaseHelper(Context context) {
        super(context, DATABASE_NAME, null, VERSION);
    }
    @Override
    public void onCreate(SQLiteDatabase db) {
    }
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    }
}

2)编写SQL创建初始代码  

db.execSQL("create table " + CrimeTable.NAME + "(" +
        " _id integer primary key autoincrement, " +
        CrimeTable.Cols.UUID + ", " +
        CrimeTable.Cols.TITLE + ", " +
        CrimeTable.Cols.DATE + ", " +
        CrimeTable.Cols.SOLVED + ", " +
        CrimeTable.Cols.SUSPECT +
        ")"
);

代码中需要导入CrimeTable，在CrimeTable一词上，

按alt+回车，选中提示选项

3）读取数据库    

调用query(...)方法查询记录

private CrimeCursorWrapper queryCrimes(String whereClause, String[] whereArgs) {
    Cursor cursor = mDatabase.query(
            CrimeTable.NAME,
            null, // Columns - null selects all columns
            whereClause,
            whereArgs,
            null, // groupBy
            null, // having
            null  // orderBy
    );
    return new CrimeCursorWrapper(cursor);
}

SQLite数据库使用

标签：wrap   ida   selected   int   ase   base   nts   androi   导入   

原文地址：http://www.cnblogs.com/JieG/p/7660088.html