我有一个SQLite
查询,返回Cursor
。我希望通过实现Cursor
向MatrixCursor
添加一些额外的行(以便在单击时自动选择保留第一项真实数据)。然后我想将它们映射到SimpleCursorAdapter
。我一直在阅读帖子(和代码),但我仍然觉得如何将其编码为下面列出的现有代码。
Cursor cursor = myDB.query(DATABASE_TABLE_NAME, resultColumns, whereClause,
whereArgs, null, null, null, null);
// Create Spinner View object from layout resource
Spinner spinner = (Spinner) findViewById(R.id.spinner);
SimpleCursorAdapter adapter = new SimpleCursorAdapter(this,
android.R.layout.simple_spinner_item, // Use a template
// that displays a
// text view
cursor, // Give the cursor to the adapter
new String[] {"ename"}, // Map the NAME column in the
// people database to...
new int[] {android.R.id.text1});
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
spinner.setOnItemSelectedListener(new MyOnItemSelectedListener());
答案 0 :(得分:5)
如果您想从简单MatrixCursor
构建Cursor
,则必须解析整个初始Cursor
并附加所需的行:
//...
MatrixCursor mc = new MatrixCursor(resultColumns);
// add extra rows, this will probably not work if you want to insert them
// between the initial cursor rows because of the _id column that need autoincrement values
mc.addRow(new Object[] { new Long(-2), "Extra name1" });
mc.addRow(new Object[] { new Long(-1), "Extra name2" });
// I don't know what your cursor holds, I assumed you have the _id column(long value)
// and a name(String value)
int size = cursor.getCount();
for (int i = 0; i < size; i++) {
cursor.moveToPosition(i);
mc.addRow(new Object[] {
cursor.getLong(cursor.getColumnIndex(/*the _id column*/)),
cursor.getString(cursor.getColumnIndex(/* the name column(ename?!?)*/)) });
}
SimpleCursorAdapter adapter = new SimpleCursorAdapter(this,
android.R.layout.simple_spinner_item, mc, new String[] {"ename"}, new int[] {android.R.id.text1});
//...
如果您这样做只是为了避免在显示OnItemSelectedListener
时触发Spinner
,也许您可以采用其他方法。例如,在你的听众中:
//boolean status = true; flag in MyOnItemSelectedListener
@Override
public void onItemSelected(AdapterView<?> parent, View view,
int position, long id) {
if (status) {
status = false;// this is the first listener trigger so you probably want to ignore it
return;
}
// do stuff here
}
注意:我不知道上述解决方案有多好。如果您看一下这个Spinner
相关问题可能有更好的解决方案。