Question

我有一个ListView，其项目可以处于以下三种状态之一：已选中，多选或无。

当选择该项时，表示用户刚刚点击它（选中它），并且该行的背景应更改为所选的drawable。

如果是多选，则表示用户长按某个项目，并将该列表置于多选模式。该初始项设置为多选，并且任何后续单击的项将被置于多选模式，直到多选结束（退格，取消选择所有多选项等）。多选行的背景应设置为多选的drawable。

否则它处于“无”状态且背景是透明的。

我遇到的问题是，当某个项目处于选定模式时，我会在View.setSelected(true)的所选位置的视图上调用getView()。我在我的应用程序中有两个地方使用此模式。在一个地方它完美地运作，但在另一个地方，似乎某些（不是我）在从View.setSelected(false)返回后在我选择的行上调用getView()。

以下是我初始化ListView的方法（通货膨胀后）：

lv.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL);
lv.setOnItemClickListener(new OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> parent, final View clickedItem, int position, long id) {
        if(adapter.isMultiSelect()) {
            ((ListView)parent).setItemChecked(position, !adapter.isPositionInMultiSelect(position));
        }
        else {
            adapter.setNewSelectedPosition(position);

            //do something
        }
    }
});
lv.setMultiChoiceModeListener(new MyMultiChoiceModeListener(adapter));

adapter.setNewSelectedPosition()来电notifyDataSetChanged()。这是我的getView()：

public View getView(final int position, View convertView, final ViewGroup parent) {     
    if(convertView == null) {
        convertView = new MyListRow(context);
    }

    boolean isSelected = isPositionInMultiSelect(position) || position == getSelectedPosition();

    SelectionType selectionType = SelectionType.NONE;
    if(isMultiSelect() && selectedPosition == position) {
        if(isPositionInMultiSelect(position)) {
            selectionType = SelectionType.MULTI_SELECT;
        }
        else {
            selectionType = SelectionType.NONE;
        }
        selectedPosition = NO_SELECTION_POSITION;
    }
    else if(isSelected) {
        if(isMultiSelect()) {
            selectionType = SelectionType.MULTI_SELECT;
        }
        else {
            selectionType = SelectionType.SELECTED_ITEM;
        }
    }

    ((MyListRow) convertView).updateViews(isSelected, selectionType);

    return convertView;
}

这是MyListRow：

public MyListRow(Context context) {
    super(context);

    LayoutInflater inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    inflater.inflate(R.layout.my_row, this, true);

    setPadding(20, 20, 20, 20);

    setViewBackground(R.drawable.list_row_selector);

    setDescendantFocusability(FOCUS_BLOCK_DESCENDANTS);     
}

public void updateViews(boolean isSelected, SelectionType selectionType) {
    if(isSelected) {
        if(selectionType == SelectionType.MULTI_SELECT) {
            setSelected(false);
        }
        else {
            setSelected(true);
        }
    }
    else {
        setSelected(false);
    }

    //do stuff
}

@SuppressWarnings("deprecation")
@SuppressLint("NewApi")
private void setViewBackground(int res) {
    Drawable d = getContext().getResources().getDrawable(res);
    Rect drawablePadding = new Rect();
    d.getPadding(drawablePadding);
    int top = getPaddingTop() + drawablePadding.top;
    int left = getPaddingLeft() + drawablePadding.left;
    int right = getPaddingRight() + drawablePadding.right;
    int bottom = getPaddingBottom() + drawablePadding.bottom;

    if(Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
        setBackgroundDrawable(d);
    }
    else {
        setBackground(d);
    }

    setPadding(left, top, right, bottom);
}

最后，这是list_row_selector.xml：

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item
    android:drawable="@drawable/list_selector_pressed"
    android:state_pressed="true" />
<item
    android:drawable="@drawable/list_selector_pressed"
    android:state_selected="true" />
<item
    android:drawable="@drawable/list_selector_activated"
    android:state_activated="true" />
<item
    android:drawable="@android:color/transparent" />

Answer 1

无论出于何种原因，post setSelected（true）使其有效：

public void updateViews(boolean isSelected, SelectionType selectionType) {
    if(isSelected) {
        if(selectionType == SelectionType.MULTI_SELECT) {
            setSelected(false);
        }
        else {
            post(new Runnable() {
                @Override
                public void run() {
                    setSelected(true);
                }
            });
        }
    }
    else {
        setSelected(false);
    }

    //do stuff
}

ListView中的Android自定义视图setSelected（true）Undone

1 个答案: