Question

所以我的问题是我在onitemclicklistener设置listview1，并且如果订单列表中已经存在项目，那么数量会增加，但我的问题是我的程序保持崩溃

这是我的代码

MainActivity.java

public class MainActivity extends Activity {
Database helper;
ListView lv,lv2;
ArrayAdapter<PostItemList> adapter;
ArrayAdapter<PostInventory> adapterInventory;
ArrayAdapter<PostOrder> adapterOrder;
ArrayList<PostItemList> list;
ArrayList<PostInventory> listInventory;
ArrayList<PostOrder> listorder;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    helper = new Database(MainActivity.this);
    lv = (ListView)findViewById(R.id.itemList);
    lv2 = (ListView)findViewById(R.id.orderList);
    list = helper.getAllData();
    adapter = new PostAdapterItemList(MainActivity.this,list);
    lv.setAdapter(adapter);
    listorder = new ArrayList<PostOrder>(); 

    lv.setOnItemClickListener(new OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> arg0, View arg1,final int pos,
            long arg3) {
        // TODO Auto-generated method stub
        PostItemList getData = list.get(pos);         
        String parseData = getData.toStringOrder();
        String name[] = parseData.split(",");

        int itemQuantity = Integer.parseInt(name[1]);
        double itemPrice = Double.parseDouble(name[2]);
        if (itemQuantity == 0){
            String output = name[0] + " is out of stock.";
            Toast.makeText(getBaseContext(), output, Toast.LENGTH_LONG).show();
        } else {

            itemQuantity = itemQuantity - 1;                    
            String newQuantity = String.valueOf(itemQuantity);
            helper.updateQuantity(name[0], newQuantity);
            list.clear();
            list = helper.getAllData();
            adapter = new PostAdapterItemList(MainActivity.this, list);
            lv.setAdapter(adapter);
            int checker = 0;
            if (listorder.isEmpty()){
                listorder.add(new PostOrder(name[0], "1", name[2]));
                adapterOrder = new PostAdapterOrder(MainActivity.this,listorder);
                lv2.setAdapter(adapterOrder);
            } else if (listorder.size()>0){
                for(PostOrder order : listorder){
                    if (name[0].contentEquals(order.getItemName())){
                        String quantity = order.getItemQuantity();
                        order.setItemQuantity(String.valueOf((Integer.parseInt(quantity))+1));  
                        adapterOrder.notifyDataSetChanged();
                    } else {
                        checker = 1;
                    }
                }                           
            }
            if (checker==1){
                listorder.add(new PostOrder(name[0], "1", name[1]));
                adapterOrder = new PostAdapterOrder(MainActivity.this, listorder);
                lv2.setAdapter(adapterOrder);
            }


        }                       
    }
});

}

logcat的

10-11 00:05:13.190: D/dalvikvm(854): GC_FOR_ALLOC freed 57K, 5% free 3034K/3176K, paused 32ms, total 33ms
10-11 00:05:13.190: I/dalvikvm-heap(854): Grow heap (frag case) to 3.646MB for 635812-byte allocation
10-11 00:05:13.290: D/dalvikvm(854): GC_FOR_ALLOC freed 0K, 4% free 3655K/3800K, paused 22ms, total 22ms
10-11 00:05:13.870: I/Choreographer(854): Skipped 73 frames!  The application may be doing too much work on its main thread.
10-11 00:05:13.950: D/gralloc_goldfish(854): Emulator without GPU emulation detected.
10-11 00:05:14.230: I/Choreographer(854): Skipped 37 frames!  The application may be doing too much work on its main thread.
10-11 00:05:20.070: D/AndroidRuntime(854): Shutting down VM
10-11 00:05:20.070: W/dalvikvm(854): threadid=1: thread exiting with uncaught exception (group=0xb3a67ba8)
10-11 00:05:20.080: E/AndroidRuntime(854): FATAL EXCEPTION: main
10-11 00:05:20.080: E/AndroidRuntime(854): Process: com.example.posv3, PID: 854
10-11 00:05:20.080: E/AndroidRuntime(854): java.util.ConcurrentModificationException
10-11 00:05:20.080: E/AndroidRuntime(854):  at java.util.ArrayList$ArrayListIterator.next(ArrayList.java:573)
10-11 00:05:20.080: E/AndroidRuntime(854):  at com.example.posv3.MainActivity$1.onItemClick(MainActivity.java:71)
10-11 00:05:20.080: E/AndroidRuntime(854):  at android.widget.AdapterView.performItemClick(AdapterView.java:299)
10-11 00:05:20.080: E/AndroidRuntime(854):  at android.widget.AbsListView.performItemClick(AbsListView.java:1113)
10-11 00:05:20.080: E/AndroidRuntime(854):  at android.widget.AbsListView$PerformClick.run(AbsListView.java:2904)
10-11 00:05:20.080: E/AndroidRuntime(854):  at android.widget.AbsListView$3.run(AbsListView.java:3638)
10-11 00:05:20.080: E/AndroidRuntime(854):  at android.os.Handler.handleCallback(Handler.java:733)
10-11 00:05:20.080: E/AndroidRuntime(854):  at android.os.Handler.dispatchMessage(Handler.java:95)
10-11 00:05:20.080: E/AndroidRuntime(854):  at android.os.Looper.loop(Looper.java:136)
10-11 00:05:20.080: E/AndroidRuntime(854):  at android.app.ActivityThread.main(ActivityThread.java:5017)
10-11 00:05:20.080: E/AndroidRuntime(854):  at java.lang.reflect.Method.invokeNative(Native Method)
10-11 00:05:20.080: E/AndroidRuntime(854):  at java.lang.reflect.Method.invoke(Method.java:515)
10-11 00:05:20.080: E/AndroidRuntime(854):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
10-11 00:05:20.080: E/AndroidRuntime(854):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
10-11 00:05:20.080: E/AndroidRuntime(854):  at dalvik.system.NativeStart.main(Native Method)

Answer 1

如果您要从iteration

中删除项目

for(Iterator<MyAdapter> it = result.iterator(); it.hasNext();) {
    MyAdapter s = it.next();
    if(s.getClientPoints().getPointsSpent() == 0) {
        it.remove();
    }   
}

Answer 2

Sir Himanshu Agarwal，谢谢你的帮助。我解决了这个问题，并且在列表中已经列出的项目列出了我的解决方案

for(PostOrder order : listorder){
                        if (name[0].contentEquals(order.getItemName())){
                            String quantity = order.getItemQuantity();
                            order.setItemQuantity(String.valueOf((Integer.parseInt(quantity))+1));  
                            adapterOrder.notifyDataSetChanged();                                    
                            break;
                        } else {
                            counter++;
                        }
                    }                           
                }                               
                if (counter == listorder.size()){
                    listorder.add(new PostOrder(name[0], "1", name[1]));
                    adapterOrder = new PostAdapterOrder(MainActivity.this, listorder);
                    lv2.setAdapter(adapterOrder);
                }

单击项目时Listview将转到另一个列表视图

2 个答案: