android:listview:获取项目点击的光标值
作者:互联网
我用列创建一个数据库和表(类别)(_id,title,…)
我想从db中读取类别并将类别列表显示为列表视图.
这是y代码:
public class MainActivity extends listActivity{
private ArrayAdapter arrayAdapter;
ArrayList results = new ArrayList();
ListView catlist;
Cursor cur;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
catlist = getListView();
int parentid = getIntent().getIntExtra("catid", 0);
openAndQueryDatabase(parentid);
displayCatListView();
}
private void displayCatListView() {
setListAdapter(new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, results));
catlist.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View v,
final int position, long id) {
Toast.makeText(MainActivity.this,
"List View Clicked:" + position, Toast.LENGTH_LONG)
.show();
}
});
}
private void openAndQueryDatabase(int parentid) {
DataBaseHelper db = new DataBaseHelper(this);
SQLiteDatabase dbr = db.getReadableDatabase();
cur = dbr.rawQuery(
"SELECT _id, title, has_sub FROM categories where parent_id=?",
new String[] { String.valueOf(parentid) });
if (cur != null) {
while (cur.moveToNext()) {
int cat_id = cur.getInt(cur.getColumnIndex("_id"));
String cattitle = cur.getString(cur.getColumnIndex("title"));
int has_sub = cur.getInt(cur.getColumnIndex("has_sub"));
results.add(cat_id + cattitle + has_sub);
}
cur.close();
}
db.close();
}
}
1)我可以获得onItemClick的位置.但是我希望获得类别_id onItemClick.请帮忙
2)我是新人.我的代码有什么错误吗?
非常感谢
解决方法:
代替
int cat_id = cur.getInt(cur.getColumnIndex("_id"));
String cattitle = cur.getString(cur.getColumnIndex("title"));
int has_sub = cur.getInt(cur.getColumnIndex("has_sub"));
results.add(cat_id + cattitle + has_sub);
创建一个Category类来包含这些值,并使用参数化的ArrayList.就像是
class Category {
public int cat_id;
public String cattitle;
public int has_sub;
public Category(int cat_id, ...) {
// constructor logic here
}
}
和
results.add(new Category(cat_id, cattitle, has_sub));
有了这个,你可以这样设置onItemClickListener:
catlist.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View v,
final int position, long id) {
Category clickedCategory = results.get(position);
int id = clickedCategory.cat_id;
// do something with id
}
});
您的ArrayList是ArrayAdapter的数据源,position对应于其中单击的Category的索引.
标签:android,android-listview,onitemclicklistener,onitemclick 来源: https://codeday.me/bug/20190714/1460382.html