自定义提供者
1 import android.content.Context;
2 import android.database.DatabaseErrorHandler;
3 import android.database.sqlite.SQLiteDatabase;
4 import android.database.sqlite.SQLiteDatabase.CursorFactory;
5 import android.database.sqlite.SQLiteOpenHelper;
6
7 public class DBHelper extends SQLiteOpenHelper {
8
9 public DBHelper(Context context) {
10 super(context, "users.db", null, 1);
11 }
12
13 @Override
14 public void onCreate(SQLiteDatabase db) {
15 // TODO 初始化数据库
16 db.execSQL("create table t_user(_id integer primary key,uname,upass,money)");
17
18 db.execSQL("create table t_order(_id integer primary key,user_id,price,productname)");
19
20 db.execSQL("insert into t_user(uname,upass,money) values(‘lisi‘,‘123‘,200)");
21
22 db.execSQL("insert into t_user(uname,upass,money) values(‘zhangsi‘,‘1234‘,2000)");
23 }
24
25 @Override
26 public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
27 // TODO 数据库升级时执行该方法
28 if(newVersion>oldVersion)
29 {
30 db.execSQL("drop table if exists t_user");
31 db.execSQL("drop table if exists t_order");
32 //并且重新初始化数据库也可以不重新加载
33 onCreate(db);
34 }
35
36 }
37
38
39
40 }
DBHelper
1 import com.qianfeng.gp08_day25_contentprovider1.tool.DBHelper;
2
3 import android.content.ContentProvider;
4 import android.content.ContentUris;
5 import android.content.ContentValues;
6 import android.content.UriMatcher;
7 import android.database.Cursor;
8 import android.database.sqlite.SQLiteDatabase;
9 import android.net.Uri;
10
11 public class UserContentProvider extends ContentProvider {
12
13 //声明该ContentProvider的唯一标识--通常使用包名+数据库名--必须小写
14 public static final String AUTHORITY ="com.qianfeng.gp08_day25_contentprovider1.users";
15
16 //为该组件中可以被外界访问的数据库中的资源定义Code标识
17 public static final int CODE_USER = 1;
18 public static final int CODE_ORDER = 8;
19
20 //定义访问资源的Uri的匹配器对象--使用该类生成被访问的资源的Uri
21 private static UriMatcher uriMatcher;
22
23 static{
24 uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
25 //content://com.qianfeng.gp08_day25_contentprovider1.users/user
26 uriMatcher.addURI(AUTHORITY, "user", CODE_USER);
27
28 //content://com.qianfeng.gp08_day25_contentprovider1.users/order
29 uriMatcher.addURI(AUTHORITY, "order", CODE_ORDER);
30 }
31
32 private DBHelper dbHelper;
33
34 @Override
35 public boolean onCreate() {
36 // TODO 初始化 数据库操作的工具类
37 dbHelper = new DBHelper(getContext());
38 return false;
39 }
40
41 @Override
42 public Cursor query(Uri uri, String[] projection, String selection,
43 String[] selectionArgs, String sortOrder) {
44 SQLiteDatabase db = dbHelper.getReadableDatabase();
45 Cursor cursor = null;
46
47 int code = uriMatcher.match(uri);
48
49 switch(code)
50 {
51 case CODE_USER:
52 cursor = db.query("t_user", projection, selection, selectionArgs, null, null, sortOrder);
53 break;
54 case CODE_ORDER:
55 cursor = db.query("t_order", projection, selection, selectionArgs, null, null, sortOrder);
56 break;
57 }
58 return cursor;
59 }
60
61
62 @Override
63 public Uri insert(Uri uri, ContentValues values) {
64 // TODO 向数据库中插入数据
65 SQLiteDatabase db =dbHelper.getWritableDatabase();
66 if(uriMatcher.match(uri)==CODE_USER)
67 {
68 long id = db.insert("t_user", null, values);
69
70 //返回新插入的记录的 Uri
71 //content://com.qianfeng.gp08_day25_contentprovider1.users/user/6
72 return ContentUris.withAppendedId(uri, id);
73 }
74 return null;
75 }
76
77 @Override
78 public int delete(Uri uri, String selection, String[] selectionArgs) {
79 // TODO 删除数据库中的数据
80 SQLiteDatabase db = dbHelper.getWritableDatabase();
81 int num = 0;
82 if(uriMatcher.match(uri)==CODE_USER)
83 {
84 num = db.delete("t_user", selection, selectionArgs);
85 }
86 return num;
87 }
88
89 @Override
90 public int update(Uri uri, ContentValues values, String selection,
91 String[] selectionArgs) {
92 // TODO 修改数据库中的数据
93 SQLiteDatabase db = dbHelper.getWritableDatabase();
94 if(uriMatcher.match(uri)==CODE_USER)
95 {
96 return db.update("t_user", values, selection, selectionArgs);
97 }
98 return 0;
99 }
100
101
102 @Override
103 public String getType(Uri uri) {
104 // TODO Auto-generated method stub
105 return null;
106 }
107
108 }
usercontentprovider
查询
1 package com.qianfeng.gp08_day25_contentresolver3;
2
3 import java.util.ArrayList;
4 import java.util.HashMap;
5 import java.util.List;
6 import java.util.Map;
7
8 import entity.Person;
9 import android.net.Uri;
10 import android.os.Bundle;
11 import android.app.Activity;
12 import android.app.AlertDialog;
13 import android.content.ContentResolver;
14 import android.content.ContentUris;
15 import android.content.ContentValues;
16 import android.content.DialogInterface;
17 import android.content.DialogInterface.OnClickListener;
18 import android.database.Cursor;
19 import android.view.ContextMenu;
20 import android.view.Menu;
21 import android.view.MenuItem;
22 import android.view.View;
23 import android.view.ContextMenu.ContextMenuInfo;
24 import android.view.View.OnCreateContextMenuListener;
25 import android.widget.AdapterView.AdapterContextMenuInfo;
26 import android.widget.ArrayAdapter;
27 import android.widget.EditText;
28 import android.widget.ListView;
29 import android.widget.Toast;
30
31 /**
32 * 访问自定义的ContentProvider---UserContentProvider
33 *
34 * @author qq
35 *
36 */
37 public class MainActivity extends Activity {
38
39 private ListView listView;
40 private List<Person> datas;
41 private ArrayAdapter adapter;
42
43 private Uri userUri = Uri
44 .parse("content://com.qianfeng.gp08_day25_contentprovider1.users/user");
45 private String[] columns = { "_id", "uname", "upass", "money" };
46 private int current;
47 private boolean isAdd;
48 private EditText edit_name, edit_pass, edit_money;
49 private View view;
50 private AlertDialog editDialog, deleteDialog;
51
52 @Override
53 protected void onCreate(Bundle savedInstanceState) {
54 super.onCreate(savedInstanceState);
55 setContentView(R.layout.activity_main);
56
57 listView = (ListView) findViewById(R.id.listView);
58 edit_name = (EditText) findViewById(R.id.edit_name);
59 edit_pass = (EditText) findViewById(R.id.edit_pass);
60 edit_money = (EditText) findViewById(R.id.edit_money);
61 datas = new ArrayList<Person>();
62 adapter = new ArrayAdapter<Person>(this,
63 android.R.layout.simple_list_item_1, datas);
64
65 listView.setAdapter(adapter);
66 registerForContextMenu(listView);
67
68 loadData();
69 initDialog();
70 }
71
72 private void loadData() {
73
74 Cursor cursor = getContentResolver().query(userUri, columns, null,
75 null, null);
76
77 while (cursor.moveToNext()) {
78 long id = cursor.getLong(0);
79 String name = cursor.getString(1);
80 String pass = cursor.getString(2);
81 int money = cursor.getInt(3);
82 Person person = new Person();
83 person.set_id(id);
84 person.setMoney(money);
85 person.setUname(name);
86 datas.add(person);
87 }
88 cursor.close();//-------------------------
89 adapter.notifyDataSetChanged();
90 }
91
92 @Override
93 public void onCreateContextMenu(ContextMenu menu, View v,
94 ContextMenuInfo menuInfo) {
95 getMenuInflater().inflate(R.menu.item, menu);
96 current = ((AdapterContextMenuInfo) menuInfo).position;
97 super.onCreateContextMenu(menu, v, menuInfo);
98 }
99
100 @Override
101 public boolean onContextItemSelected(MenuItem item) {
102 switch (item.getItemId()) {
103 case R.id.action_update:
104 isAdd = false;
105 edit_name.setText(datas.get(current).getUname());
106 edit_pass.setText(datas.get(current).getPass());
107 edit_money.setText("" + datas.get(current).getMoney());
108 editDialog.show();
109 break;
110 case R.id.action_delete:
111 deleteDialog.show();
112 break;
113 case R.id.action_add:
114 isAdd = true;
115 edit_name.setText("");
116 edit_pass.setText("");
117 edit_money.setText("");
118 editDialog.show();
119 break;
120 }
121 return super.onContextItemSelected(item);
122 }
123
124 private void showDatas() {
125 datas.clear();
126 ContentResolver resolver = getContentResolver();
127 // 先从联系人表中查询所有人的信息
128 Cursor cursor = resolver.query(userUri, columns, null, null, null);
129 while (cursor.moveToNext()) {
130 long id = cursor.getLong(0);
131 String name = cursor.getString(1);
132 String pass = cursor.getString(2);
133 int money = cursor.getInt(3);
134 Person person = new Person();
135 person.set_id(id);
136 person.setMoney(money);
137 person.setUname(name);
138 person.setPass(pass);
139 datas.add(person);
140 }
141 cursor.close();//----------------------
142 adapter.notifyDataSetChanged();
143 }
144
145 public void initDialog() {
146 view = getLayoutInflater().inflate(R.layout.dialog, null);
147 edit_name = (EditText) view.findViewById(R.id.edit_name);
148 edit_pass = (EditText) view.findViewById(R.id.edit_pass);
149 edit_money = (EditText) view.findViewById(R.id.edit_money);
150
151 editDialog = new AlertDialog.Builder(this).setTitle("联系人添加对话框")
152 .setIcon(android.R.drawable.ic_menu_add).setView(view)
153 .setPositiveButton("确定", new OnClickListener() {
154 @Override
155 public void onClick(DialogInterface dialog, int which) {
156 String name = edit_name.getText().toString();
157 String pass = edit_pass.getText().toString();
158 String money = edit_money.getText().toString();
159
160 ContentValues value = new ContentValues();
161
162 if (isAdd) {
163 if(!name.equals(""))
164 {
165 value.put("uname", name);
166 value.put("upass", pass);
167 value.put("money", money);
168 getContentResolver().insert(userUri, value);
169 }
170 else Toast.makeText(MainActivity.this, "名字不能为空", Toast.LENGTH_SHORT).show();
171 } else {
172 value.put("uname", name);
173 value.put("upass", pass);
174 value.put("money", money);
175 long id = datas.get(current).get_id();
176 getContentResolver().update(userUri, value, "_id="+id, null);
177 }
178 showDatas();
179 }
180 }).setNegativeButton("取消", null).setCancelable(false).create();
181
182 deleteDialog = new AlertDialog.Builder(this).setTitle("提示")
183 .setMessage("确实要删除吗?")
184 .setIcon(android.R.drawable.ic_menu_delete)
185 .setPositiveButton("确定", new OnClickListener() {
186
187 @Override
188 public void onClick(DialogInterface dialog, int which) {
189 long id = datas.get(current).get_id();
190 getContentResolver().delete(userUri, "_id=" + id, null);
191
192 showDatas();
193 }
194 }).setNegativeButton("取消", null).setCancelable(false).create();
195 }
196
197 }
MainActivity
查询结果放在listView中长按有上下文菜单选择增删改访问数据库操作数据库
时间： 2024-10-16 01:45:43