Android 中ContentProvider内容提供者和ContentResolver内容访问者

今天利用空闲时间研究了下ContentProvider,当应用继承ContentProvider类，并重写该类用于提供数据和存储数据的方法，就可以向其他应用共享其数据。

@Override
public boolean onCreate() {
DbHelper dbHelper=new DbHelper(getContext(),"person.db",null,2);
sqLiteDatabase = dbHelper.getReadableDatabase();
//匹配器
uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
uriMatcher.addURI("com.example.g0825_android_16.PERSONS","persons",1);
uriMatcher.addURI("com.example.g0825_android_16.PERSONS","persons/#",2);
return false;
}

@Nullable
@Override
public Cursor query(Uri uri, String[] strings, String s, String[] strings1, String s1) {
int type=uriMatcher.match(uri);
switch (type){
//所有
case 1:
return sqLiteDatabase.query(false,"person",strings,s,strings1,null,null,s1,null);
case 2:
long id=ContentUris.parseId(uri);
return sqLiteDatabase.query(false,"person",strings,"_id=?",new String[]{id+""},null,null,s1,null);
}
return null;
}

@Nullable
@Override
public String getType(Uri uri) {
return null;
}

@Nullable
@Override

 public Uri insert(Uri uri, ContentValues contentValues) {
Log.i("test","insert");
contentValues.get("name");
contentValues.get("age");
sqLiteDatabase.insert("person","name",contentValues);
return null;
}

@Override
public int delete(Uri uri, String s, String[] strings) {
return sqLiteDatabase.delete("person",s,strings);
}

@Override
public int update(Uri uri, ContentValues contentValues, String s, String[] strings) {

return sqLiteDatabase.update("person",contentValues,s,strings);
}

2.在AndroidManifest.xml中配置

<provider
android:authorities="com.example.g0825_android_16.PERSONS"
android:name="com.zking.provider.MypersonProvider"
android:exported="true"
></provider>

3.接收者中的代码

public void onClick(View view) {
//判断输入框是否为空
if(TextUtils.isEmpty(et_main_id.getText().toString())){
//查询所有
//协议   http://www.baidu.com //content://
uri = Uri.parse("content://com.example.g0825_android_16.PERSONS/persons");
}else{
//查询单个
String id=et_main_id.getText().toString();
uri = Uri.parse("content://com.example.g0825_android_16.PERSONS/persons/"+id);
}
//访问数据
Cursor cursor=cr.query(uri,null,null,null,null);
while(cursor.moveToNext()){
int pid=cursor.getInt(cursor.getColumnIndex("_id"));
String name=cursor.getString(cursor.getColumnIndex("name"));
int age=cursor.getInt(cursor.getColumnIndex("age"));
Toast.makeText(MainActivity.this, pid+" "+name+" "+age, Toast.LENGTH_SHORT).show();
}
}

//解析布局文件
View v=getLayoutInflater().inflate(R.layout.dialog_listview,null);
et_dialog_listview_name = (EditText) v.findViewById(R.id.et_dialog_listview_name);
et_dialog_listview_age = (EditText) v.findViewById(R.id.et_dialog_listview_age);
((Button)v.findViewById(R.id.btn_dialog_listview_sure)).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
String name=et_dialog_listview_name.getText().toString();
String age=et_dialog_listview_age.getText().toString();
ContentValues contentValues=new ContentValues();
contentValues.put("name",name);
contentValues.put("age",age);
uri = Uri.parse("content://com.example.g0825_android_16.PERSONS");
cr.insert(uri,contentValues);
Toast.makeText(MainActivity.this, "执行添加操作", Toast.LENGTH_SHORT).show();
dialog.dismiss();//关闭当前的对话框
}