Android GridView 多选

Question

我实现并激活了 GridView

mGridView.setChoiceMode(GridView.CHOICE_MODE_MULTIPLE_MODAL);

模式。现在，当我长按一个项目时，我可以从我的网格中选择多个项目。我想通过正常的短按来实现此行为。这可能吗？

Answer 1

首先，我建议考虑这个用户场景是否正是您一直在寻找的。默认情况下，在 Android UX 中选择你长按的东西，这是用户习惯的模式。所以，也许您应该重新考虑整个流程。

话说，你真的需要GridView.CHOICE_MODE_MULTIPLE_MODAL吗？

您可以在适配器级别处理它，只需存储选定的位置并在 onClick 处理程序中更新此列表:

static final String[] numbers = new String[] {
        "A", "B", "C", "D", "E",....
        "U", "V", "W", "X", "Y", "Z"};

.....

gridView = (GridView) findViewById(R.id.gridView1);
final CustomAdapter adapter = new CustomAdapter(numbers);
gridView.setAdapter(adapter);
gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    public void onItemClick(AdapterView<?> parent, View v,
                            int position, long id) {
        int selectedIndex = adapter.selectedPositions.indexOf(position);
        if (selectedIndex > -1) {
            adapter.selectedPositions.remove(selectedIndex);
            ((CustomView)v).display(false);
        } else {
            adapter.selectedPositions.add(position);
            ((CustomView)v).display(true);
        }
    }
});

自定义 BaseAdapter 以显示自定义 View :

public class CustomAdapter extends BaseAdapter {
    private String[] strings;
    List<Integer> selectedPositions = new ArrayList<>();

    CustomAdapter(String [] strings) {
        this.strings = strings;
    }

    @Override
    public int getCount() {
        return strings.length;
    }

    @Override
    public Object getItem(int position) {
        return strings[position];
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        CustomView customView = (convertView == null) ? 
                                    new CustomView(MainActivity.this) : (CustomView) convertView;
        customView.display(strings[position], selectedPositions.contains(position));
        return customView;
    }
}

自定义 View (在我的例子中 - 带有 TextView 的单元格)。 XML:

<merge xmlns:android="http://schemas.android.com/apk/res/android">
    <TextView
        android:id="@+id/textView"
        android:textColor="#FFF"
        android:gravity="center"
        android:layout_width="match_parent"
        android:layout_height="60dp" />
</merge>

代码:

class CustomView extends FrameLayout {

    TextView textView;

    public CustomView(Context context) {
        super(context);
        LayoutInflater.from(context).inflate(R.layout.custom_view, this);
        textView = (TextView)getRootView().findViewById(R.id.textView);
    }

    public void display(String text, boolean isSelected) {
        textView.setText(text);
        display(isSelected);
    }

    public void display(boolean isSelected) {
        textView.setBackgroundColor(isSelected? Color.RED : Color.LTGRAY);
    }
}