ContentProvider的实现
这几天有些忙，要做关于访问exchange服务器的技术调研，环境总出问题。微软的东西还真复杂！看了看android2.2的源码，本来想写点东西，但想想也没什么好写的。主要是关于软键盘事件的传递，网上有很多这方面的文章。今天看了看contentprovider，就写点这方面的东西吧。
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android为我们提供了ContentProvider来实现数据的共享，一个程序如果想让别的程序可以操作自己的数据，就定义自己的ContentProvider。今天就简单介绍一它的实现方法。换肤可能会用到。
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第一步：继承ContentProvider，代码如下:
package com.test.android.skin.main;import java.util.List;import android.content.ContentProvider;import android.content.ContentValues;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;import android.net.Uri;import android.util.Log;public class Provider extends ContentProvider{private SQLiteOpenHelper helper;@Overridepublic boolean onCreate() {helper = new SqLHelper(this.getContext());return false;}@Overridepublic Cursor query(Uri uri, String[] projection, String selection,String[] selectionArgs, String sortOrder) {List<String> paths = uri.getPathSegments();String tableName = paths.get(0);SQLiteDatabase db = helper.getReadableDatabase();return db.query(tableName, null, null, null, null, null, null);}@Overridepublic String getType(Uri uri) {return null;}@Overridepublic Uri insert(Uri uri, ContentValues values) {List<String> paths = uri.getPathSegments();String tableName = paths.get(0);Log.d("Tag",tableName + ":::"+uri.toString());SQLiteDatabase db = helper.getWritableDatabase();db.insert(tableName, null, values);return uri;}@Overridepublic int delete(Uri uri, String selection, String[] selectionArgs) {return 0;}@Overridepublic int update(Uri uri, ContentValues values, String selection,String[] selectionArgs) {return 0;}}?
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第二部：在AndroidManifest.xml添加provider
<provider android:authorities="com.test.android.skin.main.provider" android:name="Provider"></provider>
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以上就做完一个provider了。
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使用方式：
package com.test.android.skin.myskin;import android.app.Activity;import android.content.ContentResolver;import android.content.ContentValues;import android.database.Cursor;import android.net.Uri;import android.os.Bundle;import android.util.Log;public class MainActivity extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); ContentResolver resolver = this.getContentResolver(); Uri url = Uri.parse("content://com.test.android.skin.main.provider/skinTab"); ContentValues values = new ContentValues(); values.put("id", "40"); values.put("packname", "org.yangzc.package40"); resolver.insert(url, values); Uri queryurl = Uri.parse("content://com.test.android.skin.main.provider/skinTab"); Cursor c = resolver.query(queryurl, null, null, null, null); while(c.moveToNext()){ String id = c.getString(c.getColumnIndex("id")); String packname = c.getString(c.getColumnIndex("packname")); Log.d("Tag", "Id:"+id + " packname:" + packname); } }}?