好的，我花了我的时间。我从SQLiteDatabase 提出自己的简单建议实施。
我们将创建 3 个类，如下所示
-
MainActivity - 用于测试来自数据库的 SearchView 建议
-
SuggestionDatabase - 这将存储您最近的搜索关键字。
-
SuggestionSimpleCursorAdapter - 这是SimpleCursorAdapter 的子类。我会解释为什么我做这个类而不是使用SimpleCursorAdapter。
代码
// MainActivity.java
public class MainActivity
extends Activity
implements SearchView.OnQueryTextListener,
SearchView.OnSuggestionListener
{
private SuggestionsDatabase database;
private SearchView searchView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
database = new SuggestionsDatabase(this);
searchView = (SearchView) findViewById(R.id.searchView1);
searchView.setOnQueryTextListener(this);
searchView.setOnSuggestionListener(this);
}
@Override
public boolean onSuggestionSelect(int position) {
return false;
}
@Override
public boolean onSuggestionClick(int position) {
SQLiteCursor cursor = (SQLiteCursor) searchView.getSuggestionsAdapter().getItem(position);
int indexColumnSuggestion = cursor.getColumnIndex( SuggestionsDatabase.FIELD_SUGGESTION);
searchView.setQuery(cursor.getString(indexColumnSuggestion), false);
return true;
}
@Override
public boolean onQueryTextSubmit(String query) {
long result = database.insertSuggestion(query);
return result != -1;
}
@Override
public boolean onQueryTextChange(String newText) {
Cursor cursor = database.getSuggestions(newText);
if(cursor.getCount() != 0)
{
String[] columns = new String[] {SuggestionsDatabase.FIELD_SUGGESTION };
int[] columnTextId = new int[] { android.R.id.text1};
SuggestionSimpleCursorAdapter simple = new SuggestionSimpleCursorAdapter(getBaseContext(),
android.R.layout.simple_list_item_1, cursor,
columns , columnTextId
, 0);
searchView.setSuggestionsAdapter(simple);
return true;
}
else
{
return false;
}
}
}
它是如何工作的
- 当用户点击搜索按钮时，
onQueryTextSubmit() 将被触发，然后搜索关键字将保存在我们的数据库中。假设我们提交了一个关键字“Hello”
- 如果用户在
SearchView 中写入例如“Hel”或“H”的字符串，则将调用onQueryTextChange()，然后我们在SQLiteDatabase (SuggestionDatabase) 中搜索此关键字。如果 "Hel" 或 "H" 与 "Hello" 匹配，则通过将返回的 Cursor 设置为 SuggestionSimpleCursorAdapter 来显示查询结果，然后将此适配器设置为 SearchView。这是图片。
3. 当然我们会点击“你好”的建议，onSuggestionClick(int position) 会被调用。我们从SearchView的适配器（SuggestionSimpleCursorAdapter）中获取SQLiteCursor对象并从中获取建议文本，将建议文本设置在SearchView对象中
SQLiteCursor cursor = (SQLiteCursor) searchView.getSuggestionsAdapter().getItem(position);
int indexColumnSuggestion = cursor.getColumnIndex( SuggestionsDatabase.FIELD_SUGGESTION);
searchView.setQuery(cursor.getString(indexColumnSuggestion), false);
如果我们使用SimpleCursorAdapter，它也可以正常工作，但假设我们有这种情况
- 如果我们在智能手机上运行此程序并输入关键字“Hel”，建议将正确显示。
- 如果我们横向旋转屏幕会怎样？它将切换到全屏模式，您仍然可以输入关键字。
建议会发生什么？一起来看看吧。
看到奇怪的建议了吗？我们如何解决这个问题？通过覆盖返回CharSequence的convertToString(Cursor cursor)
// SuggestionSimpleCursorAdapter.java
public class SuggestionSimpleCursorAdapter
extends SimpleCursorAdapter
{
public SuggestionSimpleCursorAdapter(Context context, int layout, Cursor c,
String[] from, int[] to) {
super(context, layout, c, from, to);
}
public SuggestionSimpleCursorAdapter(Context context, int layout, Cursor c,
String[] from, int[] to, int flags) {
super(context, layout, c, from, to, flags);
}
@Override
public CharSequence convertToString(Cursor cursor) {
int indexColumnSuggestion = cursor.getColumnIndex(SuggestionsDatabase.FIELD_SUGGESTION);
return cursor.getString(indexColumnSuggestion);
}
}
通过覆盖 convertToString(Cursor cursor) ，结果如下
这是数据库
// SuggestionDatabase.java
public class SuggestionsDatabase {
public static final String DB_SUGGESTION = "SUGGESTION_DB";
public final static String TABLE_SUGGESTION = "SUGGESTION_TB";
public final static String FIELD_ID = "_id";
public final static String FIELD_SUGGESTION = "suggestion";
private SQLiteDatabase db;
private Helper helper;
public SuggestionsDatabase(Context context) {
helper = new Helper(context, DB_SUGGESTION, null, 1);
db = helper.getWritableDatabase();
}
public long insertSuggestion(String text)
{
ContentValues values = new ContentValues();
values.put(FIELD_SUGGESTION, text);
return db.insert(TABLE_SUGGESTION, null, values);
}
public Cursor getSuggestions(String text)
{
return db.query(TABLE_SUGGESTION, new String[] {FIELD_ID, FIELD_SUGGESTION},
FIELD_SUGGESTION+" LIKE '"+ text +"%'", null, null, null, null);
}
private class Helper extends SQLiteOpenHelper
{
public Helper(Context context, String name, CursorFactory factory,
int version) {
super(context, name, factory, version);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE "+TABLE_SUGGESTION+" ("+
FIELD_ID+" integer primary key autoincrement, "+FIELD_SUGGESTION+" text);");
Log.d("SUGGESTION", "DB CREATED");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
}
}
我希望这个答案对其他程序员有用。 :)