说说ContentProvider的用法
最近写了一个数据库，这个数据库的服务没包装在Provider中，导致在测试的时候老是出现Cursor没有关闭的问题，搞不定，所以决定把数据的增删查改都写在Provider中，刚开始的时候不知道怎么写，参考了下源码中的闹钟的Provider。
下面是系统源码中的闹钟的Provider：
1 /*
2 * Copyright (C) 2007 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package com.android.alarmclock;
18
19 import android.content.ContentProvider;
20 import android.content.ContentUris;
21 import android.content.ContentValues;
22 import android.content.Context;
23 import android.content.UriMatcher;
24 import android.database.Cursor;
25 import android.database.SQLException;
26 import android.database.sqlite.SQLiteDatabase;
27 import android.database.sqlite.SQLiteOpenHelper;
28 import android.database.sqlite.SQLiteQueryBuilder;
29 import android.net.Uri;
30 import android.text.TextUtils;
31
32 public class AlarmProvider extends ContentProvider {
33 private SQLiteOpenHelper mOpenHelper;
34
35 private static final int ALARMS = 1;
36 private static final int ALARMS_ID = 2;
37 private static final UriMatcher sURLMatcher = new UriMatcher(
38 UriMatcher.NO_MATCH);
39
40 static {
41 sURLMatcher.addURI("com.android.alarmclock", "alarm", ALARMS);
42 sURLMatcher.addURI("com.android.alarmclock", "alarm/#", ALARMS_ID);
43 }
44
45 private static class DatabaseHelper extends SQLiteOpenHelper {
46 private static final String DATABASE_NAME = "alarms.db";
47 private static final int DATABASE_VERSION = 5;
48
49 public DatabaseHelper(Context context) {
50 super(context, DATABASE_NAME, null, DATABASE_VERSION);
51 }
52
53 @Override
54 public void onCreate(SQLiteDatabase db) {
55 db.execSQL("CREATE TABLE alarms (" +
56 "_id INTEGER PRIMARY KEY," +
57 "hour INTEGER, " +
58 "minutes INTEGER, " +
59 "daysofweek INTEGER, " +
60 "alarmtime INTEGER, " +
61 "enabled INTEGER, " +
62 "vibrate INTEGER, " +
63 "message TEXT, " +
64 "alert TEXT);");
65
66 // insert default alarms
67 String insertMe = "INSERT INTO alarms " +
68 "(hour, minutes, daysofweek, alarmtime, enabled, vibrate, message, alert) " +
69 "VALUES ";
70 db.execSQL(insertMe + "(7, 0, 127, 0, 0, 1, '', '');");
71 db.execSQL(insertMe + "(8, 30, 31, 0, 0, 1, '', '');");
72 db.execSQL(insertMe + "(9, 00, 0, 0, 0, 1, '', '');");
73 }
74
75 @Override
76 public void onUpgrade(SQLiteDatabase db, int oldVersion, int currentVersion) {
77 if (Log.LOGV) Log.v(
78 "Upgrading alarms database from version " +
79 oldVersion + " to " + currentVersion +
80 ", which will destroy all old data");
81 db.execSQL("DROP TABLE IF EXISTS alarms");
82 onCreate(db);
83 }
84 }
85
86 public AlarmProvider() {
87 }
88
89 @Override
90 public boolean onCreate() {
91 mOpenHelper = new DatabaseHelper(getContext());
92 return true;
93 }
94
95 @Override
96 public Cursor query(Uri url, String[] projectionIn, String selection,
97 String[] selectionArgs, String sort) {
98 SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
99
100 // Generate the body of the query
101 int match = sURLMatcher.match(url);
102 switch (match) {
103 case ALARMS:
104 qb.setTables("alarms");
105 break;
106 case ALARMS_ID:
107 qb.setTables("alarms");
108 qb.appendWhere("_id=");
109 qb.appendWhere(url.getPathSegments().get(1));
110 break;
111 default:
112 throw new IllegalArgumentException("Unknown URL " + url);
113 }
114
115 SQLiteDatabase db = mOpenHelper.getReadableDatabase();
116 Cursor ret = qb.query(db, projectionIn, selection, selectionArgs,
117 null, null, sort);
118
119 if (ret == null) {
120 if (Log.LOGV) Log.v("Alarms.query: failed");
121 } else {
122 ret.setNotificationUri(getContext().getContentResolver(), url);
123 }
124
125 return ret;
126 }
127
128 @Override
129 public String getType(Uri url) {
130 int match = sURLMatcher.match(url);
131 switch (match) {
132 case ALARMS:
133 return "vnd.android.cursor.dir/alarms";
134 case ALARMS_ID:
135 return "vnd.android.cursor.item/alarms";
136 default:
137 throw new IllegalArgumentException("Unknown URL");
138 }
139 }
140
141 @Override
142 public int update(Uri url, ContentValues values, String where, String[] whereArgs) {
143 int count;
144 long rowId = 0;
145 int match = sURLMatcher.match(url);
146 SQLiteDatabase db = mOpenHelper.getWritableDatabase();
147 switch (match) {
148 case ALARMS_ID: {
149 String segment = url.getPathSegments().get(1);
150 rowId = Long.parseLong(segment);
151 count = db.update("alarms", values, "_id=" + rowId, null);
152 break;
153 }
154 default: {
155 throw new UnsupportedOperationException(
156 "Cannot update URL: " + url);
157 }
158 }
159 if (Log.LOGV) Log.v("*** notifyChange() rowId: " + rowId + " url " + url);
160 getContext().getContentResolver().notifyChange(url, null);
161 return count;
162 }
163
164 @Override
165 public Uri insert(Uri url, ContentValues initialValues) {
166 if (sURLMatcher.match(url) != ALARMS) {
167 throw new IllegalArgumentException("Cannot insert into URL: " + url);
168 }
169
170 ContentValues values;
171 if (initialValues != null)
172 values = new ContentValues(initialValues);
173 else
174 values = new ContentValues();
175
176 if (!values.containsKey(Alarm.Columns.HOUR))
177 values.put(Alarm.Columns.HOUR, 0);
178
179 if (!values.containsKey(Alarm.Columns.MINUTES))
180 values.put(Alarm.Columns.MINUTES, 0);
181
182 if (!values.containsKey(Alarm.Columns.DAYS_OF_WEEK))
183 values.put(Alarm.Columns.DAYS_OF_WEEK, 0);
184
185 if (!values.containsKey(Alarm.Columns.ALARM_TIME))
186 values.put(Alarm.Columns.ALARM_TIME, 0);
187
188 if (!values.containsKey(Alarm.Columns.ENABLED))
189 values.put(Alarm.Columns.ENABLED, 0);
190
191 if (!values.containsKey(Alarm.Columns.VIBRATE))
192 values.put(Alarm.Columns.VIBRATE, 1);
193
194 if (!values.containsKey(Alarm.Columns.MESSAGE))
195 values.put(Alarm.Columns.MESSAGE, "");
196
197 if (!values.containsKey(Alarm.Columns.ALERT))
198 values.put(Alarm.Columns.ALERT, "");
199
200 SQLiteDatabase db = mOpenHelper.getWritableDatabase();
201 long rowId = db.insert("alarms", Alarm.Columns.MESSAGE, values);
202 if (rowId < 0) {
203 throw new SQLException("Failed to insert row into " + url);
204 }
205 if (Log.LOGV) Log.v("Added alarm rowId = " + rowId);
206
207 Uri newUrl = ContentUris.withAppendedId(Alarm.Columns.CONTENT_URI, rowId);
208 getContext().getContentResolver().notifyChange(newUrl, null);
209 return newUrl;
210 }
211
212 public int delete(Uri url, String where, String[] whereArgs) {
213 SQLiteDatabase db = mOpenHelper.getWritableDatabase();
214 int count;
215 long rowId = 0;
216 switch (sURLMatcher.match(url)) {
217 case ALARMS:
218 count = db.delete("alarms", where, whereArgs);
219 break;
220 case ALARMS_ID:
221 String segment = url.getPathSegments().get(1);
222 rowId = Long.parseLong(segment);
223 if (TextUtils.isEmpty(where)) {
224 where = "_id=" + segment;
225 } else {
226 where = "_id=" + segment + " AND (" + where + ")";
227 }
228 count = db.delete("alarms", where, whereArgs);
229 break;
230 default:
231 throw new IllegalArgumentException("Cannot delete from URL: " + url);
232 }
233
234 getContext().getContentResolver().notifyChange(url, null);
235 return count;
236 }
237 }
其实对于数据库的操作，无非是四种，增删查改；在这里我仿照系统的闹钟的Provider自己写了一个Provider。以供以后忘记了的时候好参考参考：
首先我们邀创建一个数据库，并确定数据库是否生成。
1 package com.test.provider;
2
3 import android.content.ContentValues;
4 import android.content.Context;
5 import android.database.sqlite.SQLiteDatabase;
6 import android.database.sqlite.SQLiteOpenHelper;
7 import android.net.Uri;
8 import android.provider.BaseColumns;
9
10 public class AppDataBase extends SQLiteOpenHelper {
11
12 //数据库的名字
13 private static final String DATABASE_NAME = "test.db";
14 private static final int DATABASE_VERSION = 1;
15 //数据表的名字
16 private static final String TABLE_NAME = "test";
17 //数据表中的字段
18 public static final String FIELD_ID = "field_id";
19 public static final String FIELD_SHOW = "field_show";
20 public static final String FIELD_LOCTION = "field_location";
21
22 //用于表示该数据的一个Uri
23 public static final Uri CONTENT_URI = Uri.parse("content://com.fermax.monitor/apps");
24
25 //创建数据库
26 public AppDataBase (Context context) {
27 super(context, DATABASE_NAME, null, DATABASE_VERSION);
28 }
29
30 //创建表
31 @Override
32 public void onCreate (SQLiteDatabase db) {
33 String sql = "Create table "+TABLE_NAME+"("+BaseColumns._ID + " integer primary key autoincrement," +
34 FIELD_ID + " integer not null, " +
35 FIELD_LOCTION + " integer not null, " +
36 FIELD_SHOW + " integer not null );";
37 db.execSQL(sql);
38
39 initDataBase(db);
40 }
41
42 //初始化表
43 private void initDataBase (SQLiteDatabase db) {
44 ContentValues cv = new ContentValues();
45 cv.put(FIELD_ID, 1);
46 cv.put(FIELD_LOCTION, 1);
47 cv.put(FIELD_SHOW, 1);
48 db.insert(TABLE_NAME, null, cv);
49
50 cv.clear();
51 cv.put(FIELD_ID, 2);
52 cv.put(FIELD_LOCTION, 2);
53 cv.put(FIELD_SHOW, 1);
54 db.insert(TABLE_NAME, null, cv);
55
56 cv.clear();
57 cv.put(FIELD_ID, 3);
58 cv.put(FIELD_LOCTION, 3);
59 cv.put(FIELD_SHOW, 0);
60 db.insert(TABLE_NAME, null, cv);
61
62 cv.clear();
63 cv.put(FIELD_ID, 4);
64 cv.put(FIELD_LOCTION, 4);
65 cv.put(FIELD_SHOW, 1);
66 db.insert(TABLE_NAME, null, cv);
67
68 cv.clear();
69 cv.put(FIELD_ID, 5);
70 cv.put(FIELD_LOCTION, 5);
71 cv.put(FIELD_SHOW, 0);
72 db.insert(TABLE_NAME, null, cv);
73
74 cv.clear();
75 cv.put(FIELD_ID, 6);
76 cv.put(FIELD_LOCTION, 6);
77 cv.put(FIELD_SHOW, 0);
78 db.insert(TABLE_NAME, null, cv);
79
80 cv.clear();
81 cv.put(FIELD_ID, 7);
82 cv.put(FIELD_LOCTION, 7);
83 cv.put(FIELD_SHOW, 0);
84 db.insert(TABLE_NAME, null, cv);
85
86 cv.clear();
87 cv.put(FIELD_ID, 8);
88 cv.put(FIELD_LOCTION, 8);
89 cv.put(FIELD_SHOW, 1);
90 db.insert(TABLE_NAME, null, cv);
91
92 cv.clear();
93 cv.put(FIELD_ID, 9);
94 cv.put(FIELD_LOCTION, 9);
95 cv.put(FIELD_SHOW, 0);
96 db.insert(TABLE_NAME, null, cv);
97
98 cv.clear();
99 cv.put(FIELD_ID, 10);
100 cv.put(FIELD_LOCTION, 10);
101 cv.put(FIELD_SHOW, 0);
102 db.insert(TABLE_NAME, null, cv);
103
104 cv.clear();
105 cv.put(FIELD_ID, 11);
106 cv.put(FIELD_LOCTION, 11);
107 cv.put(FIELD_SHOW, 0);
108 db.insert(TABLE_NAME, null, cv);
109
110 cv.clear();
111 cv.put(FIELD_ID, 12);
112 cv.put(FIELD_LOCTION, 12);
113 cv.put(FIELD_SHOW, 0);
114 db.insert(TABLE_NAME, null, cv);
115
116 cv.clear();
117 cv.put(FIELD_ID, 13);
118 cv.put(FIELD_LOCTION, 13);
119 cv.put(FIELD_SHOW, 0);
120 db.insert(TABLE_NAME, null, cv);
121
122 cv.clear();
123 cv.put(FIELD_ID, 14);
124 cv.put(FIELD_LOCTION, 14);
125 cv.put(FIELD_SHOW, 1);
126 db.insert(TABLE_NAME, null, cv);
127
128 cv.clear();
129 cv.put(FIELD_ID, 15);
130 cv.put(FIELD_LOCTION, 15);
131 cv.put(FIELD_SHOW, 1);
132 db.insert(TABLE_NAME, null, cv);
133
134 cv.clear();
135 cv.put(FIELD_ID, 16);
136 cv.put(FIELD_LOCTION, 16);
137 cv.put(FIELD_SHOW, 1);
138 db.insert(TABLE_NAME, null, cv);
139
140 cv.clear();
141 cv.put(FIELD_ID, 17);
142 cv.put(FIELD_LOCTION, 17);
143 cv.put(FIELD_SHOW, 0);
144 db.insert(TABLE_NAME, null, cv);
145
146 cv.clear();
147 cv.put(FIELD_ID, 18);
148 cv.put(FIELD_LOCTION, 18);
149 cv.put(FIELD_SHOW, 1);
150 db.insert(TABLE_NAME, null, cv);
151
152 cv.clear();
153 cv.put(FIELD_ID, 19);
154 cv.put(FIELD_LOCTION, 19);
155 cv.put(FIELD_SHOW, 0);
156 db.insert(TABLE_NAME, null, cv);
157
158 cv.clear();
159 cv.put(FIELD_ID, 20);
160 cv.put(FIELD_LOCTION, 20);
161 cv.put(FIELD_SHOW, 0);
162 db.insert(TABLE_NAME, null, cv);
163
164 cv.clear();
165 cv.put(FIELD_ID, 21);
166 cv.put(FIELD_LOCTION, 21);
167 cv.put(FIELD_SHOW, 0);
168 db.insert(TABLE_NAME, null, cv);
169
170 cv.clear();
171 cv.put(FIELD_ID, 22);
172 cv.put(FIELD_LOCTION, 22);
173 cv.put(FIELD_SHOW, 0);
174 db.insert(TABLE_NAME, null, cv);
175
176 cv.clear();
177 cv.put(FIELD_ID, 23);
178 cv.put(FIELD_LOCTION, 23);
179 cv.put(FIELD_SHOW, 0);
180 db.insert(TABLE_NAME, null, cv);
181
182 cv.clear();
183 cv.put(FIELD_ID, 24);
184 cv.put(FIELD_LOCTION, 24);
185 cv.put(FIELD_SHOW, 0);
186 db.insert(TABLE_NAME, null, cv);
187 }
188
189 //用于更新表
190 @Override
191 public void onUpgrade (SQLiteDatabase db, int oldVersion, int newVersion) {
192 String sql=" DROP TABLE IF EXISTS "+TABLE_NAME;
193 db.execSQL(sql);
194 onCreate(db);
195 }
196 }
上面是创建了一个数据库并初始化了很多值，但我们并不知道数据库是否生成了，我们可以写一个测试类，来测试一下数据库是否生成了。
package com.test.provider;
import android.test.AndroidTestCase;
/**
* test the database.
* @author shang
*
*/
public class DBTest extends AndroidTestCase {
//用于测试数据库是否生成
public void TestHomeDB() throws Exception {
AppDataBase appDataBase = new AppDataBase(this.getContext());
appDataBase.getWritableDatabase();
}
}
写完测试类后不要忘记在manifest.xml文件中加上包和instrumentation：
1 <!-- android:targetPackage 是用来存放生成的数据库的位置的，可以和manifest中的package相同 -->
2 <instrumentation
3 android:name="android.test.InstrumentationTestRunner"
4 android:targetPackage="com.test.provider"
5 android:label="test for my app"/>
如下所示：
还有测试包，这个放在application下面，上面一个放在manifest根目录下面：
1 <!-- 这个是用来说明android测试的包 -->
2 <uses-library android:name="android.test.runner"/>
然后运行测试包，看data中对应的目录下生成了数据库文件没有：
我们可以看到生成了数据库了，好了，既然生成了数据库，我们就要把数据库的增删查改包装在一个Provider中，这个Provider是要继承ContentProvider的：
1 package com.test.provider;
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.database.sqlite.SQLiteOpenHelper;
10 import android.database.sqlite.SQLiteQueryBuilder;
11 import android.net.Uri;
12 import android.text.TextUtils;
13 import android.util.Log;
14
15 public class AppProvider extends ContentProvider {
16
17 private SQLiteOpenHelper mOpenHelper;
18
19 //用于做所有的操作
20 private static final int APPS = 1;
21
22 //用于做跟ID有关的操作
23 private static final int APPS_ID = 2;
24
25 //初始化UriMatcher
26 private static final UriMatcher mUriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
27
28 //在UriMatcher中加入指定的Uri
29 static {
30 mUriMatcher.addURI("com.fermax.monitor", "apps", APPS);
31 mUriMatcher.addURI("com.fermax.monitor", "apps/#", APPS_ID);
32 }
33
34 //拿到OpenHelper的对象
35 @Override
36 public boolean onCreate () {
37 mOpenHelper = new AppDataBase(getContext());
38 return true;
39 }
40
41 //做查询操作
42 @Override
43 public Cursor query (Uri uri, String[] projection, String selection,
44 String[] selectionArgs, String sortOrder) {
45 SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
46
47 int match = mUriMatcher.match(uri);
48 switch (match) {
49 //直接查询表中的所有的数据
50 case APPS:
51 qb.setTables("test");
52 break;
53
54 //根据Id查询
55 case APPS_ID:
56 qb.setTables("test");
57 qb.appendWhere("_id =");
58
59 //拿到Uri后面的第一个参数，并将它赋给数据库中的字段_id.
60 qb.appendWhere(uri.getPathSegments().get(1));
61 break;
62
63 default:
64 throw new IllegalArgumentException("Unknow Uri " + uri);
65 }
66
67 //根据指定的条件查询数据，并返回Cursor
68 SQLiteDatabase db = mOpenHelper.getReadableDatabase();
69 Cursor ret = qb.query(db, projection, selection, selectionArgs, null, null, sortOrder);
70 if(ret == null) {
71 Log.v("ddd","apps: apps query failed");
72 } else {
73 ret.setNotificationUri(getContext().getContentResolver(), uri);
74 }
75 return ret;
76 }
77
78 //返回给定的Uri数据的MIME类型
79 @Override
80 public String getType (Uri uri) {
81 int match = mUriMatcher.match(uri);
82 switch (match) {
83 case APPS:
84 return "vnd.android.cursor.dir/apps";
85
86 case APPS_ID:
87 return "vnd.android.cursor.item/apps";
88
89 default:
90 throw new IllegalArgumentException("Unknow uri");
91 }
92 }
93
94 //做插入操作
95 @Override
96 public Uri insert (Uri uri, ContentValues initialValues) {
97 //插入操作要对所有的字段插入，如果带有参数，则报异常
98 if(mUriMatcher.match(uri) != APPS) {
99 throw new IllegalArgumentException("Can not insert into uri " + uri);
100 }
101
102 //将给定的值插入数据库，如果给的值为空，则设默认值0
103 ContentValues values;
104 if(initialValues != null) {
105 values = new ContentValues(initialValues);
106 } else {
107 values = new ContentValues();
108 }
109
110 if(!values.containsKey(AppDataBase.FIELD_ID)) {
111 values.put(AppDataBase.FIELD_ID, 0);
112 }
113
114 if(!values.containsKey(AppDataBase.FIELD_LOCTION)) {
115 values.put(AppDataBase.FIELD_LOCTION, 0);
116 }
117
118 if(!values.containsKey(AppDataBase.FIELD_SHOW)) {
119 values.put(AppDataBase.FIELD_SHOW, 0);
120 }
121
122 //向表中插入数据。
123 SQLiteDatabase db = mOpenHelper.getWritableDatabase();
124 long rowId = db.insert("test", null, values);
125 if(rowId < 0) {
126 throw new IllegalArgumentException("Failed to insert to " + uri);
127 }
128
129 Uri newUri = ContentUris.withAppendedId(AppDataBase.CONTENT_URI, rowId);
130 getContext().getContentResolver().notifyChange(newUri, null);
131 return newUri;
132 }
133
134 //删除数据
135 @Override
136 public int delete (Uri uri, String selection, String[] selectionArgs) {
137 SQLiteDatabase db = mOpenHelper.getWritableDatabase();
138 int count;
139 int match = mUriMatcher.match(uri);
140 switch (match) {
141
142 //如果没有参数，则删除指定的参数的列
143 case APPS:
144 count = db.delete("test", selection, selectionArgs);
145 break;
146
147 //如果带有参数ID，则删除指定的参数和指定Id的列
148 case APPS_ID:
149 String segment = uri.getPathSegments().get(1);
150 if(TextUtils.isEmpty(selection)) {
151 selection = "_id=" + segment;
152 } else {
153 selection = "_id=" + segment + "and (" + selection + ")" ;
154 }
155
156 //执行删除操作
157 count = db.delete("test", selection, selectionArgs);
158 break;
159
160 default:
161 throw new IllegalArgumentException("can not delete from uri " + uri);
162
163 }
164 getContext().getContentResolver().notifyChange(uri, null);
165 return count;
166 }
167
168 //执行更新操作
169 @Override
170 public int update (Uri uri, ContentValues values, String selection,
171 String[] selectionArgs) {
172 int count;
173 long rowId = 0;
174 int match = mUriMatcher.match(uri);
175 SQLiteDatabase db = mOpenHelper.getWritableDatabase();
176 switch (match) {
177 //对指定的id的列进行更新
178 case APPS_ID:
179
180 //拿到Uri参数中的id，并转化成long类型，然后根据指定的id更新
181 String segment = uri.getPathSegments().get(1);
182 rowId = Long.valueOf(segment);
183 count = db.update("test", values, "_id = " + rowId, null);
184 break;
185
186 default:
187 throw new IllegalArgumentException("can not update the uri " + uri);
188 }
189 getContext().getContentResolver().notifyChange(uri, null);
190 return count;
191 }
192
193 }
完了之后我们要在manifest里面注册这个Provider：
1 <!-- 注册数据库的Provider -->
2 <provider
3 android:name=".AppProvider"
4 android:authorities="com.fermax.monitor"
5 android:exported="true"/
完了之后就可以在测试类中测试了，用Provider做增删查改非常方便：
1
2 //用于测试插入一条数据到数据库
3 public void testInsert() throws Exception {
4 ContentValues cv = new ContentValues();
5 cv.put(AppDataBase.FIELD_ID, 100);
6 cv.put(AppDataBase.FIELD_LOCTION, 100);
7 cv.put(AppDataBase.FIELD_SHOW, 100);
8 getContext().getContentResolver().insert(AppDataBase.CONTENT_URI, cv);
9 }
10
11 //用于测试从数据库中删除一条数据
12 public void testDelete() throws Exception {
13 int _id = 25;
14 String uriStr = "content://com.fermax.monitor/apps/" + _id;
15 Uri uri = Uri.parse(uriStr);
16 getContext().getContentResolver().delete(uri, null, null);
17 }
18
19 //用于测试从数据库中查询数据
20 public void testQuery() throws Exception {
21 Cursor c = getContext().getContentResolver().query(AppDataBase.CONTENT_URI, null, null, null, null);
22 if(c != null && c.getCount() != 0) {
23 while(c.moveToNext()) {
24 int location = c.getInt(c.getColumnIndexOrThrow(AppDataBase.FIELD_LOCTION));
25 System.out.println("location = " + location);
26 }
27 }
28 c.close();
29 }
30
31 //用于测试从数据库中更新一条数据
32 public void testUpdate() throws Exception {
33 int _id = 24;
34 String uriString = "content://com.fermax.monitor/apps/" + _id;
35 Uri uri = Uri.parse(uriString);
36 ContentValues cv = new ContentValues();
37 cv.put(AppDataBase.FIELD_LOCTION, 150);
38 getContext().getContentResolver().update(uri, cv, null, null);
39 }
运行完成之后可以去数据库中查看数据库中的数据是否发生了变化，这里我就不在赘述。
下面是这个工程的打包文件：
点击我下载
