android contentprovider

花了一天时间，把contentprovider搞明白了.大家可以去下载代码（免积分的，就是要共享，不要任何好处）：http://download.youkuaiyun.com/detail/crazy_zhangqiang/4477123

创建过程:

1，(第一步)创建自己的contentprovider:我的代码如下：

public class MyContentProvider extends ContentProvider {


//这里是静态方法的调用,因此该方法被执行
    private static final UriMatcher sURIMatcher = buildUriMatcher();


    /**
     * Builds up a UriMatcher for search suggestion and shortcut refresh queries.
     */
    private static UriMatcher buildUriMatcher() {
   
        UriMatcher matcher =  new UriMatcher(UriMatcher.NO_MATCH);
        // to get definitions...
        matcher.addURI("com.example.content1.mycontentprovider", "grils", 1);
        matcher.addURI("com.example.content1.mycontentprovider","grils/#",2);
        /* The following are unused in this implementation, but if we include
         * {@link SearchManager#SUGGEST_COLUMN_SHORTCUT_ID} as a column in our suggestions table, we
         * could expect to receive refresh queries when a shortcutted suggestion is displayed in
         * Quick Search Box, in which case, the following Uris would be provided and we
         * would return a cursor with a single item representing the refreshed suggestion data.
         */
   
        return matcher;
    }

@Override
public boolean onCreate() {
// TODO Auto-generated method stub
Log.i("Provider", "==========>mycontent");
return false;
}


@Override
public Cursor query(Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder) {
// TODO Auto-generated method stub

switch(sURIMatcher.match(uri))
{
case 1:
Log.i("Grils","fullcontent");
break;

case 2:
Log.i("Grils","content in id");
String rowId = uri.getLastPathSegment();
Log.i("rowId=====>",rowId);
break;
}
return null;
}


@Override
public String getType(Uri uri) {
// TODO Auto-generated method stub
return null;
}


@Override
public Uri insert(Uri uri, ContentValues values) {
// TODO Auto-generated method stub
return null;
}


@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
// TODO Auto-generated method stub
return 0;
}


@Override
public int update(Uri uri, ContentValues values, String selection,
String[] selectionArgs) {
// TODO Auto-generated method stub
return 0;
}
}

//上面的红色内容是关键，仔细研究一下，在第二个红色内容中，有log输出，证明创建成功

2.(第二步)修改androidmanifest.xml:如下：

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.content1"
    android:versionCode="1"
    android:versionName="1.0" >


    <uses-sdk
        android:minSdkVersion="16"
        android:targetSdkVersion="15" />


    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/title_activity_main" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />


                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        
        <provider 
            android:name=".MyContentProvider"
            android:authorities="com.example.content1.mycontentprovider"
            ></provider>
    </application>


</manifest>

注：关注红色字体,在这里告知系统我有一个内容提供者.系统自动生成。

contentprovider己经准备好了.下面是测试;

3.(第三步)activity_main.xml:

<RelativeLayout 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" >


    <Button 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world"
        android:onClick="btnclick"
        />
</RelativeLayout>

4.(第四步)mainactivity.java:

public class MainActivity extends Activity {


    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }


    public void btnclick(View v)
    {
   
    Uri uri = Uri.parse("content://com.example.content1.mycontentprovider/girls");
    this.managedQuery(uri, null, null, null, null);
    Uri uri1 = Uri.parse("content://com.example.content1.mycontentprovider/girls/22");
    this.managedQuery(uri1, null, null, null, null);
    }
}

运行，单击按钮，log 输出，完成