我有两个按钮：+和 - 。我希望当我点击按钮+时，片段类（列表视图外）中存在的textview的值会发生变化。我怎么能这样做？
这是我的Adapter类：
public class CartBaseAdapter extends BaseAdapter {
private Context mContext;
private ArrayList<PojoCart> mList;
private ViewHolder viewHolder;
private HashMap<String, Integer> mHashMap = new HashMap<String, Integer>();
private Integer total;
private DataBaseHandler dbh;
private int Id = 1;
private String value1, value2;
private int z;
private FragmentTransactionListener fragmentTransactionListener = (FragmentTransactionListener) new Cart();
public CartBaseAdapter(Context mContext, ArrayList<PojoCart> mList) {
this.mContext = mContext;
this.mList = mList;
dbh = new DataBaseHandler(mContext);
}
@Override
public int getCount() {
return mList.size();
}
@Override
public Object getItem(int position) {
return mList.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
if (convertView == null) {
LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.cart_item, parent, false);
viewHolder = new ViewHolder();
viewHolder.mImgItem = (ImageView) convertView.findViewById(R.id.cart_image);
viewHolder.mTvItemName = (TextView) convertView.findViewById(R.id.tv_item_name);
viewHolder.mTvItemPrice = (TextView) convertView.findViewById(R.id.tv_item_price);
viewHolder.mTvNumber = (TextView) convertView.findViewById(R.id.tv_number);
viewHolder.mBtnAdd = (Button) convertView.findViewById(R.id.btn_add);
viewHolder.mBtnMinus = (Button) convertView.findViewById(R.id.btn_sub);
viewHolder.mImgDelete = (ImageView) convertView.findViewById(R.id.img_del);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
convertView.setTag(viewHolder);
final PojoCart pojoCart = (PojoCart) getItem(position);
viewHolder.mTvItemName.setText(pojoCart.getmItemName());
viewHolder.mTvItemPrice.setText(pojoCart.getmItemPrice());
// viewHolder.mImgDelete.setTag(pojoCart.getmCategoryId());
/* try {
URL url = new URL(pojoCart.getmItemImage());
Bitmap bmp = BitmapFactory.decodeStream(url.openConnection().getInputStream());
viewHolder.mImgItem.setImageBitmap(bmp);
} catch (Exception e) {
e.printStackTrace();
// Log.e("exception", "" + e.getMessage());
}*/
viewHolder.mImgItem.setImageBitmap(Utility.StringToBitMap(pojoCart.getmItemImage()));
viewHolder.mBtnAdd.setTag(pojoCart);
viewHolder.mBtnMinus.setTag(pojoCart);
viewHolder.mTvItemPrice.setTag(pojoCart);
viewHolder.mTvNumber.setTag(pojoCart);
viewHolder.mImgDelete.setTag(position);
if (pojoCart.getmQuantity() > 0) {
viewHolder.mTvNumber.setText("" + pojoCart.getmQuantity());
} else {
viewHolder.mTvNumber.setText("" + 0);
}
viewHolder.mBtnAdd.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
PojoCart pojoCart = (PojoCart) v.getTag();
int mValue = pojoCart.getmQuantity();
mValue++;
viewHolder.mTvNumber.setText("" + mValue);
pojoCart.setmQuantity(mValue);
notifyDataSetChanged();
value1 = viewHolder.mTvNumber.getText().toString();
value2 = pojoCart.getmItemPrice();
int x = Integer.parseInt(value1);
int y = Integer.parseInt(value2);
// viewHolder.Dish_rate.setVisibility(View.GONE);
Log.e("value1", value1);
Log.e("value2", value2);
z = x * y;
pojoCart.setmItemPrice(String.valueOf(z));
Log.e("z", "" + z);
if (x > 2) {
int n = x - 1;
int k = z / n;
Log.e("k", "" + k);
pojoCart.setmItemPrice(String.valueOf(k));
} else {
pojoCart.setmItemPrice(String.valueOf(z));
}
dbh.updateSingleRow(pojoCart.getmCategoryId(), pojoCart.getmItemPrice(), pojoCart.getmQuantity());
int total = dbh.getTotalOfAmount();
pojoCart.setmTotalPrice(total);
}
});
viewHolder.mBtnMinus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
PojoCart pojoCart = (PojoCart) v.getTag();
int mValue = pojoCart.getmQuantity();
if (mValue > 0) {
mValue--;
viewHolder.mTvNumber.setText("" + mValue);
value1 = viewHolder.mTvNumber.getText().toString();
value2 = pojoCart.getmItemPrice();
int x = Integer.parseInt(value1);
int y = Integer.parseInt(value2);
if (x >= 1) {
Log.e("value11", value1);
Log.e("value22", value2);
int n = x + 1;
Log.e("n", "" + n);
int k = y / n;
Log.e("k", "" + k);
z = k * x;
Log.e("z", "" + z);
pojoCart.setmItemPrice(String.valueOf(z));
} else {
pojoCart.setmItemPrice(pojoCart.getmItemPrice());
}
}
pojoCart.setmQuantity(mValue);
notifyDataSetChanged();
dbh.updateSingleRow(pojoCart.getmCategoryId(), pojoCart.getmItemPrice(), pojoCart.getmQuantity());
pojoCart.setmTotalPrice(dbh.getTotalOfAmount());
}
}
);
viewHolder.mImgDelete.setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View view) {
int categoryId = pojoCart.getmCategoryId();
// int id = (Integer) view.getTag();
// id++;
Log.e("removeIdFromTheTable", "" + categoryId);
dbh.delete_byID(categoryId);
mList.remove(position);
notifyDataSetChanged();
pojoCart.setmTotalPrice(dbh.getTotalOfAmount());
}
}
);
return convertView;
}
private class ViewHolder {
TextView mTvItemName, mTvItemPrice, mTvNumber;
ImageView mImgItem, mImgDelete;
Button mBtnAdd, mBtnMinus;
}
}
这是我的片段类：
public class Cart extends Fragment implements View.OnClickListener {
private ArrayList<PojoCart> mCartList;
private ListView mListView;
private CartBaseAdapter mCartBaseAdapter;
private DataBaseHandler dbh;
private List<PojoCartDataBase> pojoCartDataBase;
private TextView mTvProcesscheck, mTvTotalPrice;
private String ItemName, ItemPrice;
private String ItemImage;
private ArrayList<String> mTotalPrice;
private Toolbar toolbar;
private int ItemQuantity;
int id = 1;
private String categoryId;
private int sumOfPrice;
private PojoCart pojoCart;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_cart, container, false);
}
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
initialize();
// addData();
displayTotalAmount();
try {
getDataFromDatabase();
} catch (IOException e) {
e.printStackTrace();
}
}
private void initialize() {
mTotalPrice = new ArrayList<String>();
mCartList = new ArrayList<PojoCart>();
mListView = (ListView) getActivity().findViewById(R.id.listview_cart);
mCartBaseAdapter = new CartBaseAdapter(getContext(), mCartList);
Parcelable state = mListView.onSaveInstanceState();
mListView.setAdapter(mCartBaseAdapter);
mListView.onRestoreInstanceState(state);
mTvProcesscheck = (TextView) getActivity().findViewById(R.id.tv_checkout);
mTvTotalPrice = (TextView) getActivity().findViewById(R.id.tv_total_price);
toolbar = (Toolbar) getActivity().findViewById(R.id.toolbar);
dbh = new DataBaseHandler(getContext());
mTvProcesscheck.setOnClickListener(this);
toolbar.setTitle("Cart");
mCartBaseAdapter.notifyDataSetChanged();
final RippleView rippleView = (RippleView) getActivity().findViewById(R.id.ripple_view_cart);
rippleView.setOnRippleCompleteListener(new RippleView.OnRippleCompleteListener() {
@Override
public void onComplete(RippleView rippleView) {
Log.d("Sample", "Ripple completed");
Fragment fragment = new LogIn();
getFragmentManager().beginTransaction().replace(R.id.frame, fragment).addToBackStack(null).commit();
toolbar.setTitle("Restaurant List");
}
});
}
/* private void addData() {
for (int i = 0; i < mItemName.length; i++) {
PojoCart pojoCart = new PojoCart();
pojoCart.setmItemName(mItemName[i]);
pojoCart.setmItemPrice(mItemPrice[i]);
pojoCart.setmItemImage(mItemImage[i]);
mCartList.add(pojoCart);
}
// mCartList.add(pojoCartDataBase);
}
*/
private void getDataFromDatabase() throws IOException {
Cursor c = dbh.getAllRows();
if (c.moveToFirst()) {
while (c.isAfterLast() == false) {
// int id = c.getInt(0);
int id = c.getInt(1);
Log.e("id.....", "" + id);
ItemName = c.getString(2);
ItemPrice = c.getString(3);
Log.e("itemname", ItemName);
Log.e("itemprice", ItemPrice);
ItemQuantity = c.getInt(4);
Log.e("itemquantity", "" + ItemQuantity);
ItemImage = c.getString(5);
Log.e("itemimage.........", ItemImage);
pojoCart = new PojoCart();
pojoCart.setmItemName(ItemName);
pojoCart.setmItemPrice(ItemPrice);
pojoCart.setmItemImage(ItemImage);
pojoCart.setmQuantity(ItemQuantity);
pojoCart.setmCategoryId(id);
mCartList.add(pojoCart);
mCartBaseAdapter.notifyDataSetChanged();
c.moveToNext();
}
}
}
@Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.tv_checkout:
/* Fragment fragment = new LogIn();
getFragmentManager().beginTransaction().replace(R.id.frame, fragment).addToBackStack(null).commit();*/
// toolbar.setTitle("Checkout");
}
}
public void displayTotalAmount() {
int total = dbh.getTotalOfAmount();
mTvTotalPrice.setText(String.valueOf(total));
}
}
我想在点击按钮+和 - 时更改mTvTotalPric（Textview）的值，该按钮出现在列表视图中。我想要更改的值的textview在listview之外。
答案 0 :(得分：0)
创建界面：
public interface MyListener {
// you can define any parameter as per your requirement
public void callback(View view, int value);
}
在listview适配器中，点击按钮+或 - 如下所示使用如下界面：
MyListener ml;
ml = (MyListener) context;
ml.callback(this, "success");
在activity中实现MyListener而不是回调方法覆盖那里，而不是从片段到活动执行的操作。
答案 1 :(得分：-1)
在Adapter class创建一个interface
Adapter.class
public class CartBaseAdapter extends BaseAdapter {
private Context mContext;
private ArrayList<PojoCart> mList;
private ViewHolder viewHolder;
private HashMap<String, Integer> mHashMap = new HashMap<String, Integer>();
private Integer total;
private DataBaseHandler dbh;
private int Id = 1;
private String value1, value2;
private int z;
private FragmentTransactionListener fragmentTransactionListener = (FragmentTransactionListener) new Cart();
private SendDataToFragment sendDataToFragment;
public CartBaseAdapter(FragmentCart fragmentCart, Context mContext, ArrayList<PojoCart> mList) {
this.mContext = mContext;
this.mList = mList;
dbh = new DataBaseHandler(mContext);
sendDataToFragment = (SendDataToFragment) fragmentCart;
}
//Interface to send data from adapter to fragment
public interface SendDataToFragment {
void sendData(String Data);
}
@Override
public int getCount() {
return mList.size();
}
@Override
public Object getItem(int position) {
return mList.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
if (convertView == null) {
LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.cart_item, parent, false);
viewHolder = new ViewHolder();
viewHolder.mImgItem = (ImageView) convertView.findViewById(R.id.cart_image);
viewHolder.mTvItemName = (TextView) convertView.findViewById(R.id.tv_item_name);
viewHolder.mTvItemPrice = (TextView) convertView.findViewById(R.id.tv_item_price);
viewHolder.mTvNumber = (TextView) convertView.findViewById(R.id.tv_number);
viewHolder.mBtnAdd = (Button) convertView.findViewById(R.id.btn_add);
viewHolder.mBtnMinus = (Button) convertView.findViewById(R.id.btn_sub);
viewHolder.mImgDelete = (ImageView) convertView.findViewById(R.id.img_del);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
convertView.setTag(viewHolder);
final PojoCart pojoCart = (PojoCart) getItem(position);
viewHolder.mTvItemName.setText(pojoCart.getmItemName());
viewHolder.mTvItemPrice.setText(pojoCart.getmItemPrice());
viewHolder.mImgItem.setImageBitmap(Utility.StringToBitMap(pojoCart.getmItemImage()));
viewHolder.mBtnAdd.setTag(pojoCart);
viewHolder.mBtnMinus.setTag(pojoCart);
viewHolder.mTvItemPrice.setTag(pojoCart);
viewHolder.mTvNumber.setTag(pojoCart);
viewHolder.mImgDelete.setTag(position);
if (pojoCart.getmQuantity() > 0) {
viewHolder.mTvNumber.setText("" + pojoCart.getmQuantity());
} else {
viewHolder.mTvNumber.setText("" + 0);
}
viewHolder.mBtnAdd.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//Send data via interface to your fragment
sendDataToFragment.sendData("Your Data");
//Your existing code
}
});
viewHolder.mBtnMinus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//Send data via interface to your fragment
sendDataToFragment.sendData("Your Data");
//Your existing code
}
});
return convertView;
}
private class ViewHolder {
TextView mTvItemName, mTvItemPrice, mTvNumber;
ImageView mImgItem, mImgDelete;
Button mBtnAdd, mBtnMinus;
}
}
在fragment interface工具内部，只要在button中点击adapter，您就会获得片段中的数据。
Fragment.class
public class FragmentCart extends Fragment implements
View.OnClickListener, CartBaseAdapter.SendDataToFragment{
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.your_layout, null);
return rootView;
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
CartBaseAdapter adapter = new CartBaseAdapter(FragmentCart.this, getActivity(), yourList);
}
@Override
public void onClick(View v) {
}
@Override
public void sendData(String Data) {
//set this data to your textView
}
}