http://blog.csdn.net/woshixuye/article/details/8280879
实例代码
当数据需要在应用程序间共享时，我们就可以利用ContentProvider为数据定义一个URI。之后其他应用程序对数据进行查询或者修改时，只需要从当前上下文对象获得一个ContentResolver(内容解析器)传入相应的URI就可以了。
contentProvider和Activity一样是Android的组件，故使用前需要在AndroidManifest.xml中注册，必须放在主应用所在包或其子包下。
1 <application android:icon="@drawable/icon" android:label="@string/app_name"> 2 <activity android:name=".MainActivity" 3 android:label="@string/app_name"> 4 <intent-filter> 5 <action android:name="android.intent.action.MAIN" /> 6 <category android:name="android.intent.category.LAUNCHER" /> 7 </intent-filter> 8 <intent-filter> 9 <data android:mimeType="vnd.android.cursor.dir/person" /> 10 </intent-filter> 11 <intent-filter> 12 <data android:mimeType="vnd.android.cursor.item/person" /> 13 </intent-filter> 14 </activity> 15 <!-- 配置内容提供者,android:authorities为该内容提供者取名作为在本应用中的唯一标识 --> 16 <provider android:name=".providers.PersonProvider" 17 android:authorities="cn.xyCompany.providers.personProvider"/> 18 </application> 19 20 内容提供者和测试代码 21
1 package cn.xy.cotentProvider.app.providers;
2 import android.content.ContentProvider;
3 import android.content.ContentUris;
4 import android.content.ContentValues;
5 import android.content.UriMatcher;
6 import android.database.Cursor;
7 import android.database.sqlite.SQLiteDatabase;
8 import android.net.Uri;
9 import android.util.Log;
10 import cn.xy.cotentProvider.service.DBOpeningHelper;
11
12 /**
13 * contentProvider作为一种组件必须放在应用所在包或其子包下，主要作用是对外共享数据
14 * 测试步骤1：将本项目先部署
15 * 测试步骤2：调用测试方法
16 * @author xy
17 *
18 */
19 public class PersonProvider extends ContentProvider
20 {
21 private DBOpeningHelper dbHelper;
22
23 // 若不匹配采用UriMatcher.NO_MATCH(-1)返回
24 private static final UriMatcher MATCHER = new UriMatcher(UriMatcher.NO_MATCH);
25
26 // 匹配码
27 private static final int CODE_NOPARAM = 1;
28 private static final int CODE_PARAM = 2;
29
30 static
31 {
32 // 对等待匹配的URI进行匹配操作，必须符合cn.xyCompany.providers.personProvider/person格式
33 // 匹配返回CODE_NOPARAM，不匹配返回-1
34 MATCHER.addURI("cn.xyCompany.providers.personProvider", "person", CODE_NOPARAM);
35
36 // #表示数字 cn.xyCompany.providers.personProvider/person/10
37 // 匹配返回CODE_PARAM，不匹配返回-1
38 MATCHER.addURI("cn.xyCompany.providers.personProvider", "person/#", CODE_PARAM);
39 }
40
41 @Override
42 public boolean onCreate()
43 {
44 dbHelper = new DBOpeningHelper(this.getContext());
45 return true;
46 }
47
48 /**
49 * 外部应用向本应用插入数据
50 */
51 @Override
52 public Uri insert(Uri uri, ContentValues values)
53 {
54 SQLiteDatabase db = dbHelper.getWritableDatabase();
55 switch (MATCHER.match(uri))
56 {
57 case CODE_NOPARAM:
58 // 若主键值是自增长的id值则返回值为主键值，否则为行号，但行号并不是RecNo列
59 long id = db.insert("person", "name", values);
60 Uri insertUri = ContentUris.withAppendedId(uri, id);
61 return insertUri;
62 default:
63 throw new IllegalArgumentException("this is unkown uri:" + uri);
64 }
65 }
66
67 /**
68 * 外部应用向本应用删除数据
69 */
70 @Override
71 public int delete(Uri uri, String selection, String[] selectionArgs)
72 {
73 SQLiteDatabase db = dbHelper.getWritableDatabase();
74 switch (MATCHER.match(uri))
75 {
76 case CODE_NOPARAM:
77 return db.delete("person", selection, selectionArgs); // 删除所有记录
78 case CODE_PARAM:
79 long id = ContentUris.parseId(uri); // 取得跟在URI后面的数字
80 Log.i("provider", String.valueOf(id));
81 String where = "id = " + id;
82 if (null != selection && !"".equals(selection.trim()))
83 {
84 where += " and " + selection;
85 }
86 return db.delete("person", where, selectionArgs);
87 default:
88 throw new IllegalArgumentException("this is unkown uri:" + uri);
89 }
90 }
91
92 /**
93 * 外部应用向本应用更新数据
94 */
95 @Override
96 public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs)
97 {
98 SQLiteDatabase db = dbHelper.getWritableDatabase();
99 switch (MATCHER.match(uri))
100 {
101 case CODE_NOPARAM:
102 return db.update("person",values,selection, selectionArgs); // 更新所有记录
103 case CODE_PARAM:
104 long id = ContentUris.parseId(uri); // 取得跟在URI后面的数字
105 String where = "id = " + id;
106 if (null != selection && !"".equals(selection.trim()))
107 {
108 where += " and " + selection;
109 }
110 return db.update("person",values,where,selectionArgs);
111 default:
112 throw new IllegalArgumentException("this is unkown uri:" + uri);
113 }
114 }
115
116 /**
117 * 返回对应的内容类型
118 * 如果返回集合的内容类型，必须以vnd.android.cursor.dir开头
119 * 如果是单个元素，必须以vnd.android.cursor.item开头
120 */
121 @Override
122 public String getType(Uri uri)
123 {
124 switch(MATCHER.match(uri))
125 {
126 case CODE_NOPARAM:
127 return "vnd.android.cursor.dir/person";
128 case CODE_PARAM:
129 return "vnd.android.cursor.item/person";
130 default:
131 throw new IllegalArgumentException("this is unkown uri:" + uri);
132 }
133 }
134
135 @Override
136 public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder)
137 {
138 SQLiteDatabase db = dbHelper.getReadableDatabase();
139 switch (MATCHER.match(uri))
140 {
141 case CODE_NOPARAM:
142 return db.query("person", projection, selection, selectionArgs, null, null, sortOrder);
143 case CODE_PARAM:
144 long id = ContentUris.parseId(uri); // 取得跟在URI后面的数字
145 String where = "id = " + id;
146 if (null != selection && !"".equals(selection.trim()))
147 {
148 where += " and " + selection;
149 }
150 return db.query("person", projection, where, selectionArgs, null, null, sortOrder);
151 default:
152 throw new IllegalArgumentException("this is unkown uri:" + uri);
153 }
154 }
155
156 }
157
158
159
160 测试代码
161 package cn.xy.test.test;
162 import android.content.ContentResolver;
163 import android.content.ContentValues;
164 import android.database.Cursor;
165 import android.net.Uri;
166 import android.test.AndroidTestCase;
167 import android.util.Log;
168
169 /**
170 * 测试代码
171 * @author xy
172 *
173 */
174 public class TestProviders extends AndroidTestCase
175 {
176 // 在执行该测试方法时需要先将还有内容提供者的项目部署到Android中，否则无法找到内容提供者
177 public void testInsert()
178 {
179 Uri uri = Uri.parse("content://cn.xyCompany.providers.personProvider/person");
180 ContentResolver resolver = this.getContext().getContentResolver();
181 ContentValues values = new ContentValues();
182 values.put("name", "xy");
183 values.put("phone", "111");
184 resolver.insert(uri, values); // 内部调用内容提供者的insert方法
185 }
186
187 // 不带id参数的删除
188 public void testDelete1()
189 {
190 Uri uri = Uri.parse("content://cn.xyCompany.providers.personProvider/person");
191 ContentResolver resolver = this.getContext().getContentResolver();
192 int rowAffect = resolver.delete(uri, null, null);
193 Log.i("rowAffect", String.valueOf(rowAffect));
194 }
195
196 // 带参数的删除，通过URI传递了id至contentProvider并可追加其他条件
197 public void testDelete2()
198 {
199 Uri uri = Uri.parse("content://cn.xyCompany.providers.personProvider/person/18");
200 ContentResolver resolver = this.getContext().getContentResolver();
201 int rowAffect = resolver.delete(uri, "name = ?", new String[] { "XY2" }); // 在provider中手动进行了拼装
202 Log.i("rowAffect", String.valueOf(rowAffect));
203 }
204
205 public void testUpdate()
206 {
207 Uri uri = Uri.parse("content://cn.xyCompany.providers.personProvider/person/19");
208 ContentResolver resolver = this.getContext().getContentResolver();
209 ContentValues values = new ContentValues();
210 values.put("name", "newxy");
211 values.put("phone", "new111");
212 int rowAffect = resolver.update(uri, values, null, null);
213 Log.i("rowAffect", String.valueOf(rowAffect));
214 }
215
216 public void testQuery()
217 {
218 Uri uri = Uri.parse("content://cn.xyCompany.providers.personProvider/person/19");
219 ContentResolver resolver = this.getContext().getContentResolver();
220 Cursor cursor = resolver.query(uri, new String[]{"id","name","phone"}, null, null, "id asc");
221 if(cursor.moveToFirst())
222 {
223 Log.i("query", cursor.getString(cursor.getColumnIndex("name")));
224 }
225 cursor.close();
226 }
227 }
时间： 2024-10-11 18:07:28