我在我的 android 应用程序中处理 PayPal 沙盒付款时遇到困难。
一旦我单击通过 PayPal 按钮付款，我的应用程序就会崩溃并给我一个空指针异常。
这是我的 PayPalTask 和 PayPal 按钮 Java 代码片段：
class PaypalTask extends AsyncTask<Void, Void, Void> {
protected final char[] TOTAL_GBP=null;
public Void doInBackground(Void... arg0) {
ppObject = PayPal.initWithAppID(getBaseContext(), "APP-80W284485P519543T", PayPal.ENV_SANDBOX);
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
btnPaypal = ppObject.getCheckoutButton(getApplicationContext(), PayPal.BUTTON_278x43, CheckoutButton.TEXT_PAY);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
params.addRule(RelativeLayout.CENTER_HORIZONTAL);
params.addRule(RelativeLayout.CENTER_VERTICAL);
btnPaypal.setLayoutParams(params);
rlPay.addView(btnPaypal);
if(utils.prefs.getBoolean("isLogged", false)) btnPaypal.setVisibility(View.VISIBLE); else btnPaypal.setVisibility(View.GONE);
btnPaypal.setOnClickListener(new OnClickListener(){
public void onClick(View view) {
// to check whether there are any books in the shopping cart
if(!cid.isEmpty()){
PayPalPayment payment = new PayPalPayment();
payment.setSubtotal(new BigDecimal(TOTAL_GBP));
payment.setCurrencyType("GBP");
payment.setRecipient(Utils.PAYPAL_ACCOUNT);
payment.setPaymentType(PayPal.PAYMENT_TYPE_GOODS);
Intent checkoutIntent = PayPal.getInstance().checkout(payment, getBaseContext());
startActivityForResult(checkoutIntent, 1);
}else{
utils.showToast("Your shopping cart is empty.");
// The PayPal button needs to be updated so that the user can click on it again.
btnPaypal.updateButton();
}
}
});
}
}
如果我更改以下行：
payment.setSubtotal(new BigDecimal(TOTAL_GBP));
到任何双浮点值，例如：
payment.setSubtotal(new BigDecimal("30.00"));
然后它工作得很好，但从不从购物车中提取小计值，而只提取指定的总金额，即在这种情况下为 30.00 英镑
为了更清楚起见，我的购物车列表 Java 代码片段如下：
private void fillCartList(boolean boo){
// to delete the contents of the cartlists
this.deleteCartLists();
TOTAL_QTY = 0; TOTAL_GBP = 0;
int price, qty;
// if is not 0, first will parse all the rows to arraylists from sqlite stored on the phone
Cursor cursor = db.getJoinedTables();
if(cursor != null && cursor.getCount()!=0){
cursor.moveToFirst();
while(!cursor.isAfterLast()){
if(boo == false){
price = Integer.valueOf(cursor.getString(cursor.getColumnIndex(justdealsDatabase.KEY_BPRICE)).replace("£", ""));
qty = cursor.getInt(cursor.getColumnIndex(justdealsDatabase.KEY_CQTY));
cid.add(cursor.getInt(cursor.getColumnIndex(justdealsDatabase.KEY_BID)));
cTitle.add(cursor.getString(cursor.getColumnIndex(justdealsDatabase.KEY_BTITLE)));
cCode.add(cursor.getString(cursor.getColumnIndex(justdealsDatabase.KEY_BCODE)));
cPrice.add(price + "£");
cImage.add(cursor.getString(cursor.getColumnIndex(justdealsDatabase.KEY_BIMAGE)));
cQty.add(qty);
TOTAL_QTY += qty;
TOTAL_GBP += qty * price;
}else{
// to insert a new row to sales table on mysql db
postParameters.removeAll(postParameters);
price = Integer.valueOf(cursor.getString(cursor.getColumnIndex(justdealsDatabase.KEY_BPRICE)).replace("£", ""));
qty = cursor.getInt(cursor.getColumnIndex(justdealsDatabase.KEY_CQTY));
//information will be parsed via PHP if the internet is working
postParameters.add(new BasicNameValuePair("bid", String.valueOf(cursor.getInt(cursor.getColumnIndex(justdealsDatabase.KEY_BID)))));
Log.i(DEBUG, utils.prefs.getString("username", ""));
postParameters.add(new BasicNameValuePair("user", utils.prefs.getString("username", "")));
postParameters.add(new BasicNameValuePair("sQty", String.valueOf(qty)));
postParameters.add(new BasicNameValuePair("sDate", String.valueOf(getCurrentDate())));
postParameters.add(new BasicNameValuePair("sTotal", String.valueOf(qty * price)));
String response = null;
try{
response = CustomHttpClient.executeHttpPost(Utils.LINK_SALES, postParameters).toString();
response = response.replaceAll("\\s+", "");
Log.i(DEBUG, response);
} catch (Exception e) {
Log.e(DEBUG, "Error at fillCartList(): " + e.toString());
}
}
cursor.moveToNext();
}
}
tvValueTotalQty.setText("" + TOTAL_QTY);
tvValueTotalGBP.setText(TOTAL_GBP + "£");
}
您的建议和想法将不胜感激。非常感谢。
车架代码片段：
private static class CartHolder{
TextView tvPrice, tvTitle, tvQty, tvTotals;
public ImageView imgImage;
}
private class CartAdapter extends BaseAdapter{
private LayoutInflater inflater;
private ArrayList<String> list;
public CartAdapter(ArrayList<String> ll){
inflater = (LayoutInflater)ActivityTab.this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
list = ll;
}
//number of items in the data set are linked by this Adapter.
public int getCount() {
return list.size();
}
// to get the data item associated with the specified position in the data set.
public Object getItem(int position) {
return list.get(position);
}
// to get the row id associated with the specified position in the list.
public long getItemId(int position) {
return position;
}
// to get a View that displays the data at the specified position in the data set.
public View getView(int position, View convertView, ViewGroup parent) {
CartHolder holder;
if(convertView == null){
convertView = inflater.inflate(R.layout.item_cart, null);
holder = new CartHolder();
holder.imgImage = (ImageView)convertView.findViewById(R.id.imgImage);
holder.imgImage.getLayoutParams().height = 80;
holder.imgImage.getLayoutParams().width = 80;
holder.tvQty = (TextView)convertView.findViewById(R.id.tvNr);
holder.tvTitle = (TextView)convertView.findViewById(R.id.tvTitle);
holder.tvPrice = (TextView)convertView.findViewById(R.id.tvItemPrice);
holder.tvTotals = (TextView)convertView.findViewById(R.id.tvTotals);
convertView.setTag(holder);
}else{
holder = (CartHolder)convertView.getTag();
}
Bitmap bmp = BitmapFactory.decodeFile(cImage.get(position));
holder.tvQty.setText(String.valueOf(cQty.get(position)));
int price = Integer.valueOf(cPrice.get(position).replace("£", ""));
int qty = cQty.get(position);
int total = price * qty;
holder.imgImage.setImageBitmap(bmp);
holder.tvTitle.setText(cTitle.get(position));
holder.tvPrice.setText(cPrice.get(position));
holder.tvTotals.setText(total+"£");
return convertView;
}
}