如何在方向更改时保留所选微调器/下拉项的状态? [英] How do I preserve the state of a selected spinner/dropdown item on orientation change?

问题描述

我在我的代码中使用了一个微调下拉菜单，其中我有 4 到 5 个动态填充的值，假设我将苹果"设置为默认值，然后从下拉列表中选择橙色"并将我的屏幕旋转到横向纵向，它会返回到默认的苹果"以及与之关联的视图.如何保存状态，以便当我选择橙色"并旋转到横向时，它会填充选定的值/保持在相同的选定状态和保持视图完整/填充在与所选值对应的纵向模式中选择的视图.这是我使用的适配器代码:

I am using a spinner dropdown in my code , in which I have 4 to 5 dynamically populated values, say if I have "apples" set to default and I select "oranges" from the dropdown and rotate my screen to landscape from portrait, it goes back to default "apples" along with the view associated with it.How do I save the state such that when I select "oranges" and rotate to landscape, it populates the selected value/remains in the same selected state and keeps the view intact/populates the view that was selected in the portrait mode corresponding to the selected value. Here's the adapter code I use for the same:

public class MarketsSpinnerAdapter extends CustomRowAdapter<AdapterRow> {


    private List<AdapterRow> mRenderList;

    public MarketsSpinnerAdapter(final Context context, final List<AdapterRow> renderList) {
        super(context);


        mRenderList = new ArrayList<AdapterRow>();
        mRenderList.addAll(renderList);
    }

    @Override
    protected void setEntries(final List<AdapterRow> renderList) {
        mRenderList = renderList;
    }

    @Override
    protected List<AdapterRow> getEntries() {
        return mRenderList;
    }

    @Override
    public View getDropDownView(final int position, final View convertView, final ViewGroup parent) {
        return getEntries().get(position).getDropDownView(mContext, convertView);
    }

}

各自片段中的对应用法:

Corresponding usage in the respective fragment:

 private void populateCategoryRows(final Cursor cursor) {
            mCategories.clear();
            mAllCategories.clear();
            cursor.moveToPosition(-1);
            Map<String, String> categoryParentNames = new HashMap<String, String>();

            int selectedPosition = 0;
            String previousHeader = "";
            String previousAllHeader = "";

            while (cursor.moveToNext()) {
                final int categoryLevel = cursor.getInt(cursor.getColumnIndex(MarketsCategory.Columns.LEVEL));
                final String categoryName = cursor.getString(cursor.getColumnIndex(MarketsCategory.Columns.NAME));
                final String categoryDisplayName = cursor.getString(cursor.getColumnIndex(MarketsCategory.Columns.DISPLAY_NAME));

                if (categoryLevel == 1) {
                    categoryParentNames.put(categoryName, categoryDisplayName);
                }
            }

            cursor.moveToPosition(-1);
            while (cursor.moveToNext()) {
                final int categoryLevel = cursor.getInt(cursor.getColumnIndex(MarketsCategory.Columns.LEVEL));
                final boolean categoryIsDefault = cursor.getInt(cursor.getColumnIndex(MarketsCategory.Columns.IS_DEFAULT)) == 1;
                final boolean categoryIsSelected = cursor.getInt(cursor.getColumnIndex(MarketsCategory.Columns.IS_SELECTED)) == 1;
                final String categoryParent = cursor.getString(cursor.getColumnIndex(MarketsCategory.Columns.PARENT));
                final String categoryName = cursor.getString(cursor.getColumnIndex(MarketsCategory.Columns.NAME));
                final String categoryDisplayName = cursor.getString(cursor.getColumnIndex(MarketsCategory.Columns.DISPLAY_NAME));


                if (categoryLevel == 2 ) {
                    String categoryParentDisplayName = categoryParentNames.get(categoryParent);
                        if (!categoryParent.equals(previousHeader)) {
                            if (categoryIsSelected) {

                                mCategories.add(new CategoryHeader(categoryParentDisplayName));
                                previousHeader = categoryParent;
                            }
                        }

                        if (!categoryParent.equals(previousAllHeader)) {
                            mAllCategories.add(new CategoryHeader(categoryParentDisplayName));
                            previousAllHeader = categoryParent;
                        }

                        if (categoryIsSelected) {
                            mCategories.add(new SpinnerMarketCategoryRow(categoryName, categoryDisplayName, categoryParent));
                        }
                        mAllCategories.add(new MarketsCategoryCheckableRow(categoryName, categoryDisplayName, categoryIsSelected, categoryIsDefault));

                        if(categoryIsDefault){
                            selectedPosition = mCategories.size()-1;
                        }
                }
            }

            mSpinnerAdapter = new MarketsSpinnerAdapter(Application.getAppContext(), mCategories);
            headerView.setSpinnerAdapter(mSpinnerAdapter);
            headerView.setSpinnerSelectedItemPosition(selectedPosition);
        }
        if (selectedItem instanceof SpinnerMarketCategoryRow) {
            selectedCategory = (SpinnerMarketCategoryRow) mSpinnerAdapter.getItem(position);
        } else {
            if (mSpinnerAdapter.getCount() - 1 >= position + 1) {
                selectedCategory = (SpinnerMarketCategoryRow) mSpinnerAdapter.getItem(position + 1);
            } else {
                selectedCategory = (SpinnerMarketCategoryRow) mSpinnerAdapter.getItem(position - 1);
            }
        }

        final MarketsFragment parentFragment = (MarketsFragment) getParentFragment();
        parentFragment.onCategorySelected(selectedCategory.getCategoryName(), selectedCategory.getCategoryParentName());
    }
@Override
    public void showResults(final Uri uri) {
        LayoutUtils.showResults(getView(), headerView.getSpinnerId());
        headerView.setVisibility(View.VISIBLE);
    }

    @Override
    public void showNoResults(final Uri uri) {
        final MarketsFragment parentFragment = (MarketsFragment) getParentFragment();
        parentFragment.hideSpinner();
        //LayoutUtils.showNoResult(getView(), headerView.getSpinnerId());
    }

    @Override
    public void onDismiss(DialogInterface dialog) {
        headerView.setSelected(false);
    }
    @Override
    public void onNothingSelected(IcsAdapterView<?> parent) {
    }

有什么想法吗?

谢谢！

推荐答案

你可以这样做...

@Override
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    outState.putInt("yourSpinner", yourSpinner.getSelectedItemPosition());
    // do this for each or your Spinner
    // You might consider using Bundle.putStringArray() instead
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    // initialize all your visual fields        
    if (savedInstanceState != null) {
        yourSpinner.setSelection(savedInstanceState.getInt("yourSpinner", 0));
        // do this for each of your text views
    }
}

希望能帮到你

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