列表视图中的多选

Question

我已经使用数组适配器创建了简单的多选列表视图。我想设置背景颜色特定的列表项。但是假设我选择了 2 项意味着设置背景，并且还设置了第 12 个位置和第 22 个位置，就像自动选择的那样。请提出问题。

黑色代码。

public class MainActivity extends Activity {

ListView lvCountry;

ArrayList<Integer> list = new ArrayList<Integer>();
String[] country = { "India", "USA", "Russsia", "China", "Pakistan",
        "Canada", "UK", "arcot", "vellore", "gudiyattam", "arani",
        "palani", "chennai", "padi", "velacherry", "ambattur",
        "ambatttur ot", "maduravoyal", "guindy" };

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

    lvCountry = (ListView) findViewById(R.id.listView1);
    // Array adapter
    ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(
            MainActivity.this, android.R.layout.simple_list_item_1, country);
    lvCountry.setAdapter(arrayAdapter);

    // list selection part
    lvCountry.setOnItemClickListener(new OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> arg0, View arg1,
                int position, long arg3) {
            // color selection select item
            arg1.setBackgroundColor(Color.GRAY);
        }
    });
}}

Answer 1

实际上，当您滑动列表视图时，项目正在随机播放。为避免此问题，请将列表视图放在滚动视图中。如果您想要代码示例，我可以提供。

Answer 2

创建您自己的适配器，其中每个项目都有“已选择”标志，默认清除。在单击侦听器中为给定项目设置标志并强制重绘。你应该使用 RecuclerView，因为它工作得更快。当视图膨胀时，检查选择标志并相应地设置背景

Answer 3

XML 文件

      <ScrollView
          android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginBottom="5dp"
    android:scrollbars="none"
    android:visibility="gone">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <ListView

            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_margin="1dp"
            android:scrollbars="none"
            android:visibility="visible" />
    </LinearLayout>

</ScrollView>

java类

    listview.setAdapter(agentRequestAdapter);

    setListViewHeightBasedOnChildren(lvAgntRqstView);
         ////////////////////////////

    private static void setListViewHeightBasedOnChildren(ListView myListView) {
    try {
        ListAdapter myListAdapter = myListView.getAdapter();
        if (myListAdapter == null) {
            //do nothing return null
            return;
        }
        //set listAdapter in loop for getting final size
        int totalHeight = 0;
        for (int size = 0; size < myListAdapter.getCount(); size++) {
            View listItem = myListAdapter.getView(size, null, myListView);
            listItem.measure(0, 0);
            totalHeight += listItem.getMeasuredHeight();
        }
        //setting listview item in adapter
        ViewGroup.LayoutParams params = myListView.getLayoutParams();
        params.height = totalHeight + (myListView.getDividerHeight() * (myListAdapter.getCount() - 1));
        myListView.setLayoutParams(params);
        // print height of adapter on log
        Log.i("height of listItem:", String.valueOf(totalHeight));


    } catch (NullPointerException e) {

    }
}

Answer 4

在 bhatt4982 的这个答案中，您可以设置属性以使该选项可用于选择列表中的多个条目：

首先你可以像这个例子一样在 listView 本身中设置

    listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
    listView.setItemCanFocus(false);

其次，您可以在布局或 layout_simple_list_item_1.xml 中声明它。 示例：

    <ListView
    ...
    android:background="@drawable/your_drawable"
    android:checkMark="?android:attr/listChoiceIndicatorMultiple"/>

然后你可以在你的自定义drawable中设置背景。

Source

Answer 5

public class MainActivity extends AppCompatActivity {

List<Items> data;
RecyclerView rv;
ActionMode actionMode;
ListAdapterr listAdapterr;
int countSelected;
int total;


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

    rv = (RecyclerView) findViewById(R.id.rv);
    rv.setLayoutManager(new LinearLayoutManager(getApplicationContext()));
    CallAPI();

    rv.addOnItemTouchListener(new RecyclerItemClickListener(getApplicationContext(), rv, new RecyclerItemClickListener.OnItemClickListener() {
        @Override
        public void onItemClick(View view, int position) {

            if (countSelected > 0)
            {
                if (actionMode == null)
                {
                    actionMode = MainActivity.this.startSupportActionMode(call);
                }
                toggleSelection(position);
                String s = countSelected + " " + "S" + " " + total ;
                actionMode.setTitle(s);

                if (countSelected == 0)
                {
                    actionMode.finish();
                }
            }else if (countSelected == 0)
            {
                Toast.makeText(MainActivity.this, "Ok", Toast.LENGTH_SHORT).show();
            }
        }

        @Override
        public void onItemLongClick(View view, int position) {

            if (actionMode == null)
            {
                actionMode = MainActivity.this.startSupportActionMode(call);
            }
            toggleSelection(position);
            String s = countSelected + " " + "S" + " " + total ;
            actionMode.setTitle(s);

            if (countSelected == 0)
            {
                actionMode.finish();
            }
        }
    }));

}

ActionMode.Callback call = new ActionMode.Callback() {
    @Override
    public boolean onCreateActionMode(ActionMode mode, Menu menu) {
        mode.getMenuInflater().inflate(R.menu.menu_item,menu);
        actionMode = mode;
        countSelected = 0;
        return true;
    }

    @Override
    public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
        return false;
    }

    @Override
    public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
        return false;
    }

    @Override
    public void onDestroyActionMode(ActionMode mode) {
        if (countSelected > 0) {
            deselectAll();
        }
        actionMode = null;
    }
};

ArrayList<Items> selectedList = new ArrayList<>();

private void toggleSelection(int position) {
    data.get(position).isSelected = !data.get(position).isSelected;

    if (data.get(position).isSelected) {
        selectedList.add(data.get(position));
        countSelected++;
        total +=Integer.valueOf(data.get(position).getAmount());
    } else {
        selectedList.remove(data.get(position));
        countSelected--;
        total -= Integer.valueOf(data.get(position).getAmount());
    }
    listAdapterr.notifyDataSetChanged();
}

private void deselectAll() {
    for (int i = 0, l = data.size(); i < l; i++) {
        data.get(i).isSelected = false;
    }
    countSelected = 0;
    listAdapterr.notifyDataSetChanged();
}

回收站视图：

   public class RecyclerItemClickListener implements RecyclerView.OnItemTouchListener {
public interface OnItemClickListener {
    void onItemClick(View view, int position);
    void onItemLongClick(View view, int position);
}

private OnItemClickListener mListener;
private GestureDetector mGestureDetector;

public RecyclerItemClickListener(Context context, final RecyclerView recyclerView, OnItemClickListener listener) {
    mListener = listener;

    mGestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
        @Override
        public boolean onSingleTapUp(MotionEvent e) {
            return true;
        }

        @Override
        public void onLongPress(MotionEvent e) {
            View childView = recyclerView.findChildViewUnder(e.getX(), e.getY());

            if (childView != null && mListener != null) {
                mListener.onItemLongClick(childView, recyclerView.getChildAdapterPosition(childView));
            }
        }
    });
}

@Override
public boolean onInterceptTouchEvent(RecyclerView view, MotionEvent e) {
    View childView = view.findChildViewUnder(e.getX(), e.getY());

    if (childView != null && mListener != null && mGestureDetector.onTouchEvent(e)) {
        mListener.onItemClick(childView, view.getChildAdapterPosition(childView));
    }

    return false;
}

@Override
public void onTouchEvent(RecyclerView view, MotionEvent motionEvent) {
}

@Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {

}

}