Question

如何使用onCreateContextMenu从ListView中删除项目？下面的代码中存在一些问题。任何解决方案？

当长按列表视图中的项目时，会弹出一个菜单，其中有一个删除选项。

public class ContextMenuTest extends AppCompatActivity {

    ListView listView;
    String []name={"ANKUSH", "ANOUSHKA", "SHIVA", "SOMANSHU"};
    String current;
    ArrayAdapter<String> adapter;
    int pos;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_context_menu_test);

        listView = (ListView) findViewById(R.id.lvContextMenu);
        adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, name);

        listView.setAdapter(adapter);
        registerForContextMenu(listView);
    }


    @Override
    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
        super.onCreateContextMenu(menu, v, menuInfo);

        menu.setHeaderTitle("SELECT OPTION");
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.menu_test, menu);
    }

    @Override
    public boolean onContextItemSelected(MenuItem item) {
        AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo();
        switch (item.getItemId())
        {
            case R.id.delete:
                adapter.remove(adapter.getItem(info.position));
                break;
        }
        return true;
    }

}

Answer 1

在onContextItemSelected方法中，添加adapter.notifyDataSetChanged()以通知适配器数据更改。

public boolean onContextItemSelected(MenuItem item) {
    AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo();
    switch (item.getItemId())
    {
        case R.id.delete:
            adapter.remove(adapter.getItem(info.position));
            adapter.notifyDataSetChanged();
            break;
    }
    return true;
}

Answer 2

要使用onCreateContextMenu从ListView中删除项目，您可以这样做：

int currentposition;

listview.setOnCreateContextMenuListener(new OnCreateContextMenuListener() {

    @Override
    public void onCreateContextMenu(ContextMenu menu, View v,
            ContextMenuInfo menuInfo) {
        // TODO Auto-generated method stub
        AdapterContextMenuInfo info = (AdapterContextMenuInfo) menuInfo;
        currentposition = info.position;
        menu.setHeaderTitle("SELECT OPTION");
        menu.add(0, v.getId(), 0, "Delete ");

    }

});

然后：

public boolean onContextItemSelected(MenuItem item) {
    AdapterContextMenuInfo info = (AdapterContextMenuInfo) item
            .getMenuInfo();
    if (item.getTitle() == "Delete ") {
        mArray.remove(currentposition);
        ca.notifyDataSetChanged();
        Toast.makeText(this, "Deleted ", Toast.LENGTH_SHORT)
                .show();
    } 
    return true;
}

Answer 3

本作品

public class ContextMenuTest extends AppCompatActivity {

ListView listView;
List<String> list = new ArrayList<String>();
ArrayAdapter<String> adapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_context_menu_test);

    listView = (ListView) findViewById(R.id.lvContextMenu);

    list.add("ANKUSH");
    list.add("ANOUSHKA");
    list.add("SHIVA");
    list.add("SOMANSHU");

    adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, list);

    listView.setAdapter(adapter);
    registerForContextMenu(listView);
}


@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
    super.onCreateContextMenu(menu, v, menuInfo);

    menu.setHeaderTitle("SELECT OPTION");
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.menu_test, menu);
}

@Override
public boolean onContextItemSelected(MenuItem item) {

    AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo();

    switch (item.getItemId())
    {
        case R.id.delete:
            list.remove(info.position);
            adapter.notifyDataSetChanged();
            return true;

        default:
            return super.onContextItemSelected(item);
    }
}
}

使用onCreateContextMenu从ListView中删除项目

3 个答案: