GreenDao的简单使用说明(二)单表的增,删,改,查
leewinq
8年前
来自： http://blog.csdn.net//chenguang79/article/details/50441343
通过上一篇文章,我们已经把GreenDao框架架起来了,而且三个基础操作类和Users的用户类也建立起来了,哪么下面我们就来实现一下,对于这个单表的增,删,改,查功能.
这里说明一下,因为是做一个简单的例子,所以这里我对数据库的操作,没有做异步处理.
第一步,我们要先来写一个类BaseApplication.java,此类是用来取得GreenDao中的DaoMaster和DaoSession的,先看代码.
package com.example.cg.greendaolearn.db; import android.app.Application; import android.content.Context; import com.example.cg.greendaolearn.THDevOpenHelper; import com.guangda.dao.DaoMaster; import com.guangda.dao.DaoSession; /** * 官方推荐将取得DaoMaster对象的方法放到Application层这样避免多次创建生成Session对象。 * Created by cg on 2015/12/29. */ public class BaseApplication extends Application { private static BaseApplication mInstance; private static DaoMaster daoMaster; private static DaoSession daoSession; @Override public void onCreate() { super.onCreate(); if(mInstance == null) mInstance = this; } /** * 取得DaoMaster * * @param context 上下文 * @return DaoMaster */ public static DaoMaster getDaoMaster(Context context) { if (daoMaster == null) { DaoMaster.OpenHelper helper = new THDevOpenHelper(context,"myDb",null); daoMaster = new DaoMaster(helper.getWritableDatabase()); } return daoMaster; } /** * 取得DaoSession * * @param context 上下文 * @return DaoSession */ public static DaoSession getDaoSession(Context context) { if (daoSession == null) { if (daoMaster == null) { daoMaster = getDaoMaster(context); } daoSession = daoMaster.newSession(); } return daoSession; } } 通过代码上的注释,我们也知道了,只所以要继承自application,主要就是为了避免多次创建生成Session对象,提高性能. 第二步,建立一个操作类,把增,删,改,查的方法,全写进去.方便调用.代码如下
DbService.java
package com.example.cg.greendaolearn.db; import android.content.Context; import android.text.TextUtils; import android.util.Log; import com.guangda.dao.DaoSession; import com.guangda.dao.UsersDao; import java.util.List; import greendao.Users; /** * 用户操作类 * Created by cg on 2015/12/29. */ public class DbService { private static final String TAG = DbService.class.getSimpleName(); private static DbService instance; private static Context appContext; private DaoSession mDaoSession; private UsersDao userDao; private DbService() { } /** * 采用单例模式 * @param context 上下文 * @return dbservice */ public static DbService getInstance(Context context) { if (instance == null) { instance = new DbService(); if (appContext == null){ appContext = context.getApplicationContext(); } instance.mDaoSession = BaseApplication.getDaoSession(context); instance.userDao = instance.mDaoSession.getUsersDao(); } return instance; } /** * 根据用户id,取出用户信息 * @param id 用户id * @return 用户信息 */ public Users loadNote(long id) { if(!TextUtils.isEmpty(id + "")) { return userDao.load(id); } return null; } /** * 取出所有数据 * @return 所有数据信息 */ public List<Users> loadAllNote(){ return userDao.loadAll(); } /** * 生成按id倒排序的列表 * @return 倒排数据 */ public List<Users> loadAllNoteByOrder() { return userDao.queryBuilder().orderDesc(UsersDao.Properties.Id).list(); } /** * 根据查询条件,返回数据列表 * @param where 条件 * @param params 参数 * @return 数据列表 */ public List<Users> queryNote(String where, String... params){ return userDao.queryRaw(where, params); } /** * 根据用户信息,插件或修改信息 * @param user 用户信息 * @return 插件或修改的用户id */ public long saveNote(Users user){ return userDao.insertOrReplace(user); } /** * 批量插入或修改用户信息 * @param list 用户信息列表 */ public void saveNoteLists(final List<Users> list){ if(list == null || list.isEmpty()){ return; } userDao.getSession().runInTx(new Runnable() { @Override public void run() { for(int i=0; i<list.size(); i++){ Users user = list.get(i); userDao.insertOrReplace(user); } } }); } /** * 删除所有数据 */ public void deleteAllNote(){ userDao.deleteAll(); } /** * 根据id,删除数据 * @param id 用户id */ public void deleteNote(long id){ userDao.deleteByKey(id); Log.i(TAG, "delete"); } /** * 根据用户类,删除信息 * @param user 用户信息类 */ public void deleteNote(Users user){ userDao.delete(user); } } 这个类就不多说了,大家一看就明白,很简单,而且里面也已经比较明确的给出了注解. 第三步,设置布局文件
1,Toolbar的代码:
<?xml version="1.0" encoding="utf-8"?> <android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:id="@+id/toolbar" android:layout_width="match_parent" android:layout_height="wrap_content" android:background="?attr/colorPrimary" android:minHeight="?attr/actionBarSize" app:popupTheme="@style/ThemeOverlay.AppCompat.Light" app:theme="@style/ThemeOverlay.AppCompat.ActionBar"> </android.support.v7.widget.Toolbar>
当然了,你要是想使用toolbar,还要为其设置样式,style.xml
<resources> <style name="AppBaseTheme" parent="Theme.AppCompat.Light.NoActionBar"> <!-- toolbar（actionbar）颜色 --> <item name="colorPrimary">#4876FF</item> <!-- 状态栏颜色 --> <item name="colorPrimaryDark">#3A5FCD</item> <!--toolbar文字的颜色--> <item name="@android:textColorPrimary">@android:color/white</item> <!-- 窗口的背景颜色 --> <item name="android:windowBackground">@android:color/white</item> <!-- SearchView --> <item name="searchViewStyle">@style/MySearchViewStyle</item> <item name="actionMenuTextColor">#ffffff</item> </style> <style name="AppTheme" parent="@style/AppBaseTheme"> <item name="android:windowIsTranslucent">true</item> </style> <style name="MySearchViewStyle" parent="Widget.AppCompat.SearchView"></style> <style name="DrawerArrowStyle" parent="Widget.AppCompat.DrawerArrowToggle"> <item name="spinBars">true</item> <item name="color">@android:color/white</item> </style> </resources>
现在来看一下页面主布局,这个布局其实很简单,就是一个Toolbar,Toolbar上菜单有一个添加的按钮,而且下面是一个listView用来显示用户,点击添加按钮,弹出一个对话框,显示你要添加的项,填写完后,保存,新加的数据就会在listView中显示出来.点击列表项,会弹出对框,上面有删除与修改的选项,可以对此项进行删除与修改,
好,先来看一下activity_one_table.xml文件
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.example.cg.greendaolearn.oneTableActivity" android:orientation="vertical"> <include layout="@layout/toolbar" /> <ListView android:id="@+id/lv_oneTable" android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1" /> </LinearLayout>
接下来,看一下,toolbar菜单栏的布局文件,menu_one_table.xml.主要就是添加了一个添加的按钮
<menu xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" tools:context="com.example.cg.greendaolearn.oneTableActivity"> <item android:id="@+id/menu_onetable_add" android:title="添加" app:showAsAction="never" /> </menu>
下面是listView列表显示,哪么我们先为这个列表设置一个item的布局.代码比较简单:'
activity_onetable_lv_item.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" android:background="@color/coral"> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content"> <LinearLayout android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1"> <TextView android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:gravity="center" android:text="姓名:" android:textColor="@color/white" android:padding="5dp"/> <TextView android:id="@+id/txt_onetable_uName" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:textColor="@color/white" android:padding="5dp"/> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1"> <TextView android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:gravity="center" android:text="性别:" android:textColor="@color/white" android:padding="5dp"/> <TextView android:id="@+id/txt_onetable_uSex" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:textColor="@color/white" android:padding="5dp"/> </LinearLayout> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="5dp"> <LinearLayout android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1"> <TextView android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:gravity="center" android:text="年纪:" android:textColor="@color/white" android:padding="5dp"/> <TextView android:id="@+id/txt_onetable_age" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:textColor="@color/white" android:padding="5dp"/> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1"> <TextView android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:gravity="center" android:text="电话:" android:textColor="@color/white" android:padding="5dp"/> <TextView android:id="@+id/txt_onetable_tel" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:textColor="@color/white" android:padding="5dp"/> </LinearLayout> </LinearLayout> </LinearLayout>
为再为它设计一个Adapter
onetable_adapter.java
package com.example.cg.greendaolearn.adpater; import android.content.Context; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.TextView; import com.example.cg.greendaolearn.R; import java.util.List; import greendao.Users; /** * 用户信息显示Adapter * Created by cg on 2015/12/29. */ public class onetable_adapter extends BaseAdapter { private LayoutInflater inflater; private List<Users> list_user; public onetable_adapter(Context context,List<Users> list_user) { this.inflater = LayoutInflater.from(context); this.list_user = list_user; } @Override public int getCount() { return list_user.size(); } @Override public Object getItem(int position) { return list_user.get(position); } @Override public long getItemId(int position) { return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { userInfo uInfo; if(convertView==null) { uInfo = new userInfo(); convertView = inflater.inflate(R.layout.activity_onetable_lv_item,null); uInfo.uAge = (TextView)convertView.findViewById(R.id.txt_onetable_age); uInfo.uName = (TextView)convertView.findViewById(R.id.txt_onetable_uName); uInfo.uSex = (TextView)convertView.findViewById(R.id.txt_onetable_uSex); uInfo.uTel = (TextView)convertView.findViewById(R.id.txt_onetable_tel); convertView.setTag(uInfo); }else { uInfo = (userInfo)convertView.getTag(); } uInfo.uSex.setText(list_user.get(position).getUSex()); uInfo.uTel.setText(list_user.get(position).getUTelphone()); uInfo.uName.setText(list_user.get(position).getUName()); uInfo.uAge.setText(list_user.get(position).getUAge()); return convertView; } public class userInfo { TextView uName; TextView uSex; TextView uAge; TextView uTel; } } listVIew搞定了.我们来完成点击添加时,弹出的对话框,这里采用的DialogFragment
先看布局文件fragment_onetable_dialog.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"> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="vertical"> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content"> <LinearLayout android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1"> <TextView android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:gravity="center" android:text="姓名:"/> <EditText android:id="@+id/edit_onetable_name" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:textColor="@color/black"/> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1"> <TextView android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:gravity="center" android:text="性别:"/> <EditText android:id="@+id/edit_onetable_sex" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:textColor="@color/black"/> </LinearLayout> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content"> <LinearLayout android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1"> <TextView android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:gravity="center" android:text="电话:"/> <EditText android:id="@+id/edit_onetable_tel" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:textColor="@color/black"/> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" > <TextView android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:gravity="center" android:text="年纪:"/> <EditText android:id="@+id/edit_onetable_age" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:textColor="@color/black"/> </LinearLayout> </LinearLayout> </LinearLayout> </LinearLayout>
代码:oneTableDialogFragment.java
package com.example.cg.greendaolearn; import android.app.AlertDialog; import android.app.Dialog; import android.app.DialogFragment; import android.content.DialogInterface; import android.os.Bundle; import android.view.LayoutInflater; import android.view.View; import android.widget.EditText; /** * 用户添加与修改 * Created by cg on 2015/12/30. */ public class oneTableDialogFragment extends DialogFragment { private EditText edit_onetable_name; private EditText edit_onetable_sex; private EditText edit_onetable_tel; private EditText edit_onetable_age; private String uName; //用户姓名 private String uSex; //用户性别 private String uAge; //用户年纪 private String uTel; //用户电话 private int flag; //flag 标识 0:添加 1:修改 private long uId; //用户id,添加时为0,修改时为正确的id /** * 定义点击事件接口 */ public interface addUserOnClickListener { void onAddUserOnClick(long id,String uName, String uSex,String uAge,String uTel,int flag); } public oneTableDialogFragment(long uId,String uName, String uSex, String uAge, String uTel,int flag) { this.uName = uName; this.uSex = uSex; this.uAge = uAge; this.uTel = uTel; this.flag = flag; this.uId = uId; } @Override public Dialog onCreateDialog(Bundle savedInstanceState) { AlertDialog.Builder builder = new AlertDialog.Builder(getActivity()); // Get the layout inflater LayoutInflater inflater = getActivity().getLayoutInflater(); View view = inflater.inflate(R.layout.fragment_onetable_dialog, null); edit_onetable_name = (EditText) view.findViewById(R.id.edit_onetable_name); edit_onetable_sex = (EditText) view.findViewById(R.id.edit_onetable_sex); edit_onetable_tel = (EditText) view.findViewById(R.id.edit_onetable_tel); edit_onetable_age = (EditText)view.findViewById(R.id.edit_onetable_age); edit_onetable_name.setText(uName); edit_onetable_age.setText(uAge); edit_onetable_sex.setText(uSex); edit_onetable_tel.setText(uTel); // Inflate and set the layout for the dialog // Pass null as the parent view because its going in the dialog layout builder.setView(view) // Add action buttons .setTitle("添加用户") .setPositiveButton("添加", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int id) { addUserOnClickListener listener = (addUserOnClickListener) getActivity(); listener.onAddUserOnClick(uId,edit_onetable_name.getText().toString(), edit_onetable_sex.getText().toString(), edit_onetable_age.getText().toString(), edit_onetable_tel.getText().toString(), flag); } }).setNegativeButton("取消", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { edit_onetable_name.setText(""); edit_onetable_sex.setText(""); edit_onetable_age.setText(""); edit_onetable_tel.setText(""); } }); return builder.create(); } } 这里就不多说了,一是代码比较简单,二是里面的注释也比较清楚,大家一眼就明白了.
下面就是对点击item项的时候,弹出的对框进行设计,先看布局,就两个textView
fragment_onetable_itemdialog.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/txt_onetable_update" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="修改" android:padding="10dp" android:gravity="center"/> <View android:layout_width="match_parent" android:layout_height="1dp" android:background="@color/gray"/> <TextView android:id="@+id/txt_onetable_delete" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="删除" android:padding="10dp" android:gravity="center"/> </LinearLayout>
代码:oneTableItemDialogFragment.java
package com.example.cg.greendaolearn; import android.app.DialogFragment; import android.os.Bundle; import android.support.annotation.Nullable; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.view.Window; import android.widget.TextView; /** * Created by cg on 2015/12/30. */ public class oneTableItemDialogFragment extends DialogFragment { private long id; //用户id private int postion; //list中的编号 private TextView txt_onetable_update; private TextView txt_onetable_delete; public interface EditUserOnClickListener { //flag标识,0表示删除,1表示修改 void onEditUserOnClick(long id,int postion,int flag); } public oneTableItemDialogFragment(long id,int postion) { this.id = id; this.postion = postion; } @Nullable @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { getDialog().requestWindowFeature(Window.FEATURE_NO_TITLE); View view = inflater.inflate(R.layout.fragment_onetable_itemdialog,container); return view; } @Override public void onViewCreated(View view, Bundle savedInstanceState) { super.onViewCreated(view, savedInstanceState); txt_onetable_update = (TextView)view.findViewById(R.id.txt_onetable_update); txt_onetable_update.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { EditUserOnClickListener listener = (EditUserOnClickListener) getActivity(); listener.onEditUserOnClick(id,postion,1); } }); txt_onetable_delete = (TextView)view.findViewById(R.id.txt_onetable_delete); txt_onetable_delete.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { EditUserOnClickListener listener = (EditUserOnClickListener) getActivity(); listener.onEditUserOnClick(id,postion,0); } }); } } OK了,现在我们来看一下,主程序的代码:oneTableActivity.java
package com.example.cg.greendaolearn; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.Toolbar; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.widget.AdapterView; import android.widget.ListView; import android.widget.Toast; import com.example.cg.greendaolearn.adpater.onetable_adapter; import com.example.cg.greendaolearn.db.DbService; import java.util.ArrayList; import java.util.List; import greendao.Users; public class oneTableActivity extends AppCompatActivity implements oneTableDialogFragment.addUserOnClickListener,oneTableItemDialogFragment.EditUserOnClickListener { private Toolbar toolbar; //定义toolbar private ListView lv_oneTable; private List<Users> list_user; private onetable_adapter oAdapter; private DbService db; private oneTableItemDialogFragment oneItemDialog; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_one_table); toolbar = (Toolbar)this.findViewById(R.id.toolbar); toolbar.setTitle("单表操作"); // 标题的文字需在setSupportActionBar之前，不然会无效 setSupportActionBar(toolbar); db = DbService.getInstance(this); initControls(); initData(); } /** * 初始化数据,刚进入页面时加载 */ private void initData() { list_user = new ArrayList<>(); list_user = db.loadAllNoteByOrder(); oAdapter = new onetable_adapter(this,list_user); lv_oneTable.setAdapter(oAdapter); } /** * 初始化控件 */ private void initControls() { lv_oneTable = (ListView)findViewById(R.id.lv_oneTable); lv_oneTable.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { Toast.makeText(oneTableActivity.this,list_user.get(position).getUName() + "--" + list_user.get(position).getId(),Toast.LENGTH_SHORT).show(); oneItemDialog = new oneTableItemDialogFragment(list_user.get(position).getId(),position); oneItemDialog.show(getFragmentManager(),"编辑"); } }); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.menu_one_table, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); //noinspection SimplifiableIfStatement if (id == R.id.menu_onetable_add) { oneTableDialogFragment oneDialog = new oneTableDialogFragment(0,"","","","",0); oneDialog.show(getFragmentManager(),"添加用户"); return true; } return super.onOptionsItemSelected(item); } @Override public void onAddUserOnClick(long uId,String uName, String uSex, String uAge, String uTel,int flag) { Users user = new Users(); if(flag==1) { user.setId(uId); } user.setUSex(uSex); user.setUTelphone(uTel); user.setUAge(uAge); user.setUName(uName); if(flag==0) { if (db.saveNote(user) > 0) { list_user.add(0, user); oAdapter.notifyDataSetChanged(); } }else { if (db.saveNote(user) > 0) { int num = 0; for(Users u:list_user) { if(u.getId()==uId) { list_user.remove(num); list_user.add(num,user); break; } num++; } oAdapter.notifyDataSetChanged(); } } } @Override public void onEditUserOnClick(long id,int postion,int flag) { if(flag==0) { db.deleteNote(id); list_user.remove(postion); oAdapter.notifyDataSetChanged(); oneItemDialog.dismiss(); }else { Users updateUser = db.loadNote(id); oneTableDialogFragment oDialog = new oneTableDialogFragment(updateUser.getId(),updateUser.getUName(),updateUser.getUSex(), updateUser.getUAge(), updateUser.getUTelphone(),1); oneItemDialog.dismiss(); oDialog.show(getFragmentManager(),"修改"); } } } 运行效果图:
