为什么我自己定义的ContentProvider用contentResolve

2016-12-18 11:01:16 209 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

Android开发应用通信 ContentProvider ContentResolver 它提供了一组方法来查询ContentProviders、插入、更新和删除数据，以及注册ContentObserver以侦听数据中的更改。ContentProvider是一个Android组件，它提供了一个标准接口来在不同的应用程序之间共享数据。它充当应用程序和数据源之间的中介，数据源可以是SQLite数据库、文件，甚至是远程服务器。ContentProvider提供了一组方法来管理对数据的访问，例如查询、插入、更新和删除数据。它还支持内容URI，这些URI是表示一段数据的唯一标识符。阅读详情

这是内容提供者代码片段



	private static final UriMatcher sURIMatcher = new UriMatcher(UriMatcher.NO_MATCH);

	private static final int QUERYSUCESS = 0;  

	private static final int INSERTSUCESS = 1;

	private static final int UPDATESUCESS = 2;

	private static final int DELETESUCESS = 3;

	private MyOpenHelper myOpenHelper;

	static{

		

	

		sURIMatcher.addURI("com.itheima.provider", "query", QUERYSUCESS);

		sURIMatcher.addURI("com.itheima.provider", "insert", INSERTSUCESS);

		sURIMatcher.addURI("com.itheima.provider", "update", UPDATESUCESS);

		sURIMatcher.addURI("com.itheima.provider", "delete", DELETESUCESS);

	}

	

	



	@Override

	public boolean onCreate() {

		myOpenHelper = new MyOpenHelper(getContext());

		return false;

	}





	@Override

	public Cursor query(Uri uri, String[] projection, String selection,

			String[] selectionArgs, String sortOrder) {

		int code = sURIMatcher.match(uri);

		if (code ==QUERYSUCESS ) 

			SQLiteDatabase db = myOpenHelper.getReadableDatabase();

			Cursor cursor = db.query("info", projection, selection, selectionArgs, null, null, sortOrder);

			getContext().getContentResolver().notifyChange(uri, null);

			return cursor;

			

		}else{

			throw new IllegalArgumentException("你错了");

			

		}

			

		

	}

这是解析的



		Uri uri = Uri.parse("content://com.itheima.provider/query");



		Cursor cursor = getContentResolver().query(uri, new String[]{"name","money"}, null, null, null);

         if (cursor!=null) {

			

			while(cursor.moveToNext()){

				String name = cursor.getString(0);

				String money = cursor.getString(1);

				

				System.out.println("name:"+name+"---"+money);

				

			}

         }

这是内容提供者的清单文件

   <application

        android:allowBackup="true"

        android:icon="@drawable/ic_launcher"

        android:label="@string/app_name"

        android:theme="@style/AppTheme" >

        <activity

            android:name="com.itheima.db.MainActivity"

            android:label="@string/app_name" >

            <intent-filter>

                <action android:name="android.intent.action.MAIN" />



                <category android:name="android.intent.category.LAUNCHER" />

            </intent-filter>

        </activity>



        <!-- 配置内容提供者 -->

        <provider

            android:name="com.itheima.db.AccountProvider"

            android:readPermission="com.read"

            android:authorities="com.itheima.provider" >

        </provider>

    </application>

这是报的异常

12-18 14:39:08.586: E/AndroidRuntime(13025): FATAL EXCEPTION: main

12-18 14:39:08.586: E/AndroidRuntime(13025): Process: com.itheima.readdb, PID: 13025

12-18 14:39:08.586: E/AndroidRuntime(13025): java.lang.IllegalStateException: Could not execute method of the activity

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at android.view.View$1.onClick(View.java:3823)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at android.view.View.performClick(View.java:4438)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at android.view.View$PerformClick.run(View.java:18422)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at android.os.Handler.handleCallback(Handler.java:733)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at android.os.Handler.dispatchMessage(Handler.java:95)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at android.os.Looper.loop(Looper.java:136)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at android.app.ActivityThread.main(ActivityThread.java:5017)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at java.lang.reflect.Method.invokeNative(Native Method)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at java.lang.reflect.Method.invoke(Method.java:515)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at dalvik.system.NativeStart.main(Native Method)

12-18 14:39:08.586: E/AndroidRuntime(13025): Caused by: java.lang.reflect.InvocationTargetException

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at java.lang.reflect.Method.invokeNative(Native Method)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at java.lang.reflect.Method.invoke(Method.java:515)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at android.view.View$1.onClick(View.java:3818)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	... 11 more

12-18 14:39:08.586: E/AndroidRuntime(13025): Caused by: java.lang.SecurityException: Permission Denial: opening provider com.itheima.db.AccountProvider from ProcessRecord{b1297448 13025:com.itheima.readdb/u0a5} (pid=13025, uid=10005) that is not exported from uid 10004

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at android.os.Parcel.readException(Parcel.java:1465)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at android.os.Parcel.readException(Parcel.java:1419)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at android.app.ActivityManagerProxy.getContentProvider(ActivityManagerNative.java:2848)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at android.app.ActivityThread.acquireProvider(ActivityThread.java:4415)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at android.app.ContextImpl$ApplicationContentResolver.acquireProvider(ContextImpl.java:2192)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at android.content.ContentResolver.acquireProvider(ContentResolver.java:1378)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at android.content.ContentResolver.insert(ContentResolver.java:1184)

12-18 14:39:08.586: E/AndroidRuntime(13025): 	at com.itheima.readdb.MainActivity.click1(MainActivity.java:34)