这是这个问题的跟进 ViewPager和Fragments - 存储Fragment状态的正确方式是什么?。我需要有人来解释答案中的代码部分。
另一种方法是重写FragmentPageAdapter.instantiateItem(View, int),并在返回前保存从super调用返回的fragment的引用(如果已经存在,则它具有找到fragment的逻辑)。
我正在使用PagerAdapter将数据从cursor加载到viewpager中。我已经重写了PagerAdapter.intantiateItem。我只需要能够保存被点击的Button的状态。这是我的代码。
我也尝试了这个答案,但它没有起作用。参考链接:在ViewPager中保存Fragment状态。非常感谢。
另一种方法是重写FragmentPageAdapter.instantiateItem(View, int),并在返回前保存从super调用返回的fragment的引用(如果已经存在,则它具有找到fragment的逻辑)。
我正在使用PagerAdapter将数据从cursor加载到viewpager中。我已经重写了PagerAdapter.intantiateItem。我只需要能够保存被点击的Button的状态。这是我的代码。
public class CustomQuestionPagerAdapter extends PagerAdapter {
private Cursor cursor;
private Cursor cursorCategory;
private LayoutInflater inflater;
private Context context;
private ArrayList<String> optionsArray;
String rightAnswer;
String wrongAnswer1;
String wrongAnswer2;
Button option1;
Button option2;
Button option3;
public CustomQuestionPagerAdapter(Context context, Cursor cursor1, Cursor cursor2) {
this.context = context;
this.cursor = cursor1;
this.cursorCategory = cursor2;
this.inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
public void swapCursor(Cursor cursor) {
this.cursor = cursor;
}
public void swapAnotherCursor(Cursor cursor) {
this.cursorCategory = cursor;
}
public void destroyItem(View view, int position, Object object) {
((ViewPager) view).removeView((ScrollView) object);
}
@Override
public int getCount() {
if (cursor == null) {
return 0;
}else {
return cursor.getCount();
}
}
/* (non-Javadoc)
* @see android.support.v4.view.PagerAdapter#instantiateItem(android.view.View, int)
*/
@Override
public Object instantiateItem(View view, int position) {
cursor.moveToPosition(position);
final ViewPager pager = (ViewPager) view.findViewById(R.id.pager_nav);
ScrollView layout = (ScrollView) inflater.inflate(R.layout.question_activity, null);
if (cursorCategory != null && cursorCategory.moveToFirst()){
String s = cursorCategory.getString(cursorCategory.getColumnIndex("name"));
((TextView)layout.findViewById(R.id.text_category)).setText(s);
}
Typeface tpf = Typeface.createFromAsset(context.getAssets(), "Roboto-Light.ttf");
String text = cursor.getString(cursor.getColumnIndex("question_text"));
TextView question_text = (TextView)layout.findViewById(R.id.text_question);
question_text.setText(text);
question_text.setTypeface(tpf);
String qPos = Integer.toString(position + 1) + ".";
TextView question_position = (TextView) layout.findViewById(R.id.text_position);
question_position.setText(qPos);
question_position.setTypeface(tpf);
this.rightAnswer = cursor.getString(cursor.getColumnIndex(DBHelper.RIGHT_ANSWER));
this.wrongAnswer1 = cursor.getString(cursor.getColumnIndex(DBHelper.WRONG_ANSWER1));
this.wrongAnswer2 = cursor.getString(cursor.getColumnIndex(DBHelper.WRONG_ANSWER2));
optionsArray = new ArrayList<String>();
optionsArray.clear();
optionsArray.add(this.rightAnswer);
optionsArray.add(this.wrongAnswer1);
optionsArray.add(this.wrongAnswer2);
Collections.shuffle(optionsArray);
option1 = (Button) layout.findViewById(R.id.button_option1);
option1.setText((CharSequence) this.optionsArray.get(0));
option2 = (Button) layout.findViewById(R.id.button_option2);
option2.setText((CharSequence) this.optionsArray.get(1));
option3 = (Button) layout.findViewById(R.id.button_option3);
option3.setText((CharSequence) this.optionsArray.get(2));
final Button next = (Button) layout.findViewById(R.id.next_button);
next.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
int j = getItem(+1) + 1;
Toast.makeText(context, context.getResources().getString(R.string.question_no) + " " + j, Toast.LENGTH_SHORT).show();
pager.setCurrentItem(getItem(+1), true);
next.setBackgroundColor(0xffeeeeee); // i need to save this new bacground color
}
private int getItem(int i) {
return i += pager.getCurrentItem();
}
});
我也尝试了这个答案,但它没有起作用。参考链接:在ViewPager中保存Fragment状态。非常感谢。