Question

我目前有这段代码在列表视图中显示所选项目：

public class DisplayOrder extends AppCompatActivity {

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

    Button btn = (Button) findViewById(R.id.btnHome);
    btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent myIntent = new Intent(DisplayOrder.this, Options.class);
            startActivity(myIntent);

        }
    });
}

private void bar() {


    ListView lv = (ListView) findViewById(R.id.listViewDisplay);

    List<String> itemsOrdered = new ArrayList<String>();


    for (Map.Entry<Item, Integer> entry : Datastore.currentTable.getOrder().getItems().entrySet()) {
        itemsOrdered.add((entry.getKey().name) + " x " + String.valueOf(entry.getValue()) + " £" + (entry.getKey().price * entry.getValue()));
    }


    // This is the array adapter, it takes the context of the activity as a
    // first parameter, the type of list view as a second parameter and your
    // array as a third parameter.
    ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(getBaseContext(), R.layout.activity_display_order, R.id.textView8, itemsOrdered);

    lv.setAdapter(arrayAdapter);
}
}

我想要做的是，当我点击其中一个项目时，要将其删除，但我不知道该怎么做。任何指导都将非常感谢。

Answer 1

您应该通过ListView检测点击setOnItemClickListener的每个项目的时间然后在这个方法中，只需删除list datasource和notifyDataSetChanged

lv.setOnItemClickListener(new OnItemClickListener() {

    @Override
    public void onItemClick(AdapterView < ? > parent, View view,int position, long id) {

        itemsOrdered.remove(position); // remove item at index in list datasource
        arrayAdapter.notifyDataSetChanged(); // call it for refresh ListView

        Toast.makeText(getApplicationContext(), "remove item at " + position, Toast.LENGTH_LONG).show(); 
    }

});

Answer 2

您必须像这样覆盖侦听器“setOnItemClickListener”：

listView.setOnItemClickListener(new OnItemClickListener() {
  @Override
  public void onItemClick(AdapterView<?> parent, View view,
    int position, long id) {
    itemsOrdered.remove(item);
    arrayAdapter.notifyDataSetChanged();

  }
});

此代码从列表中删除了ítem，但您必须通知适配器的更改。当通知适配器时，列表视图会更新。

单击项目时从列表视图中删除项目

2 个答案: