我在Android开发方面很新，我试图在我的Listview上放置一个使用CursorAdapter的上下文菜单，我按照这个示例https://www.youtube.com/watch?v=Pq9YQl0nfEk Using contextmenu with listview in android但菜单没有出现，我不是没有原因，显然一切都没问题。
这是我活动的代码
public class ProductsView extends AppCompatActivity {
private FloatingActionButton botonAnadir;
private ListView lvProducts;
SetOfProductList mylist;
private ProductAdapter productAdapter;
Cursor cursor;
private ProductList productList;
private Long idProductList;
private DBManager dbManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Bundle bundle = getIntent().getExtras();
if (bundle != null){
productList = bundle.getParcelable("productList");
setTitle(getResources().getString(R.string.show_products) + " " + productList.getName());
}
setContentView(R.layout.products_view);
initialize();
}
private void initialize(){
botonAnadir = (FloatingActionButton)findViewById(R.id.button_add_product);
lvProducts = (ListView)findViewById(R.id.listViewProducts);
dbManager = new DBManager(getApplicationContext());
loadProducts();
registerForContextMenu(lvProducts);
botonAnadir.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
creaNuevaLista();
}
});
lvProducts.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Product aux = getProduct(position);
goToNewProduct(aux);
}
});
lvProducts.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
// markAsPurchased(position);
return true;
}
});
}
private void markAsPurchased(int position){
Product p = getProduct(position);
TextView item = (TextView) findViewById(R.id.textview_product_name);
if (p.getPurchased() == 0){
p.setPurchased(1); //mark as a purchased
item.setPaintFlags(item.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
}
else{
p.setPurchased(0); //mark as a purchased
item.setPaintFlags(item.getPaintFlags() & (~Paint.STRIKE_THRU_TEXT_FLAG));
}
editProduct(p); //makes de update
loadProducts();
}
private void editProduct(Product product){
dbManager.updateProduct(product);
}
private void goToNewProduct(Product p){
Intent intent = new Intent(this,NewProductActivity.class);
Bundle b = new Bundle();
b.putBoolean("editMode",true);
b.putParcelable("product", p);
intent.putExtras(b);
startActivity(intent);
}
private void creaNuevaLista(){
Intent i = new Intent(this,NewProductActivity.class);
Bundle b = new Bundle();
b.putParcelable("productList", productList);
i.putExtras(b);
startActivityForResult(i, 0);
}
private void loadProducts(){
cursor = dbManager.getAllProductsWithCursor(productList);
productAdapter = new ProductAdapter(this,cursor);
lvProducts.setAdapter(productAdapter);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
super.onCreateContextMenu(menu, v, menuInfo);
if (v.getId() == R.id.listViewProducts){
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.prodcut_view_context_menu,menu);
}
}
@Override
public boolean onContextItemSelected(MenuItem item) {
AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo();
switch (item.getItemId()){
case R.id.delete_id:
return true;
default:
return super.onContextItemSelected(item);
}
}
}
这是我正在使用的适配器
public class ProductAdapter extends CursorAdapter {
private LayoutInflater inflater;
//Constructor
public ProductAdapter(Context context, Cursor cursor) {
super(context, cursor,false);
}
// The newView method is used to inflate a new view and return it,
// you don't bind any data to the view at this point.
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
inflater = (LayoutInflater) context.getSystemService(context.LAYOUT_INFLATER_SERVICE);
View view = inflater.inflate(R.layout.layout_product_row,parent,false);
return view;
}
// The bindView method is used to bind all data to a given view
// such as setting the text on a TextView.
@Override
public void bindView(View view, Context context, Cursor cursor) {
TextView tv_product_name = (TextView) view.findViewById(R.id.textview_product_name); // Find fields to populate in inflated template
String product_name = cursor.getString(cursor.getColumnIndexOrThrow("name"));// Extract properties from cursor
// Populate fields with extracted properties
tv_product_name.setText(product_name);
if (cursor.getInt(cursor.getColumnIndexOrThrow("purchased")) == 1){
tv_product_name.setPaintFlags(tv_product_name.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
}
}
public Product getProduct(int position, Cursor cursor) {
Product p=null;
if(cursor.moveToPosition(position)) {
Log.e("PRODUCTLISTADAPTER","nombre es: "+cursor.getString(cursor.getColumnIndex("name")));
p = new Product (cursor.getLong(cursor.getColumnIndex("_id")),cursor.getString(cursor.getColumnIndex("name")),
cursor.getString(cursor.getColumnIndex("unit_type")),cursor.getDouble(cursor.getColumnIndex("value")),cursor.getInt(cursor.getColumnIndex("purchased")),cursor.getLong(cursor.getColumnIndex("id_pl")));
}
return p;
}
}
任何人都可以选择我为什么不工作？是不是必须在LongClickListener上创建一些东西？因为我没有看到正在创建菜单。
提前致谢。
答案 0 :(得分：0)
您已为OnItemLongClickListener设置ListView，该true将在创建上下文菜单之前运行。从onItemLongClick()方法返回OnItemLongClickListener表示在此处使用了长按，因此不会创建菜单。
如果您实际上不需要false，则可以删除相关代码。如果您确实需要它，出于某种原因，您可以从onItemLongClick()返回'ae' => __( 'United Arab Emirates', 'polylang' ),
，然后您的菜单就会显示。