2017-04-21 77 views
0

我有一个功能齐全的应用程序,它接受用户输入并将其保存到数据库中。点击“日志”按钮后,信息显示在列表视图中。我创建了一个for循环来保存我的一个列的总数。列名是“grandTotal”,这是我在夜间提出的一些提示。一切都很好,直到我意外地点击保存按钮而没有输入任何内容,现在它崩溃了,我无法弄清楚如何找到解决方法。任何帮助,将不胜感激!我的代码如下:Android应用程序在向数据库输入值时关闭

@Override 
public View getView(int position, View convertView, ViewGroup parent) { 

    if (inflater == null) 
     inflater = (LayoutInflater) activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
    if (convertView == null) 
     convertView = inflater.inflate(R.layout.contact_entry, null); 

    TextView name= (TextView) convertView.findViewById(R.id.contactName); 
    TextView contact = (TextView) convertView.findViewById(R.id.contact); 
    TextView address = (TextView) convertView.findViewById(R.id.addressConverted); 
    TextView orderTotal = (TextView) convertView.findViewById(R.id.orderTotalConverted); 
    TextView amountReceived = (TextView) convertView.findViewById(R.id.amountReceivedConverted); 
    TextView tip = (TextView) convertView.findViewById(R.id.tipConverted); 
    TextView mileage = (TextView) convertView.findViewById(R.id.mileageConverted); 
    TextView grandTotal = (TextView) convertView.findViewById(R.id.grandTotalConverted); 
    Button delete = (Button) convertView.findViewById(R.id.delete); 

    PhoneBook list = contactList.get(position); 

    name.setText(list.getName()); 
    contact.setText(list.getPhoneNumber()); 
    address.setText(list.getAddress()); 
    orderTotal.setText(list.getOrderTotal()); 
    amountReceived.setText(list.getAmountReceived()); 
    tip.setText(list.getTip()); 
    mileage.setText(list.getMileage()); 
    grandTotal.setText(list.getGrandTotal()); 
    delete.setOnClickListener(new ListItemClickListener(position, list)); 


    TextView deliveryNumber = (TextView) convertView.findViewById(R.id.deliveryNum); 
    deliveryNumber.setText("Delivery # " + (position + 1)); 

    TextView runningTotal = (TextView) convertView.findViewById(R.id.runningTotal); 

    float sum = 0; 
    for (int i = 0; i <= position; i++) 
    { 
     sum = Float.valueOf(list.getGrandTotal()) + sum; 
    } 
    runningTotal.setText("Running Total: " + sum); 

    return convertView; 
} 

我得到的错误是这行代码在我的for循环:

sum = Float.valueOf(list.getGrandTotal()) + sum; 

就像我说的,应用程序正在运行伟大,只要我实际上是将数据保存到数据库中,但是当我保存(没有)时,它最终崩溃并且从此没有运行。

我得到的logcat的错误是:

FATAL EXCEPTION: main 
                       Process: com.example.boley.databaseexample, PID: 23988 
                       java.lang.NumberFormatException: Invalid float: "" 
                        at java.lang.StringToReal.invalidReal(StringToReal.java:63) 
                        at java.lang.StringToReal.parseFloat(StringToReal.java:308) 
                        at java.lang.Float.parseFloat(Float.java:306) 
                        at java.lang.Float.valueOf(Float.java:343) 
                        at com.example.boley.databaseexample.PhonebookAdapter.getView(PhonebookAdapter.java:86) 
                        at android.widget.AbsListView.obtainView(AbsListView.java:2929) 
                        at android.widget.ListView.measureHeightOfChildren(ListView.java:1305) 
                        at android.widget.ListView.onMeasure(ListView.java:1212) 
                        at android.view.View.measure(View.java:20158) 
                        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6328) 
                        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1464) 
                        at android.widget.LinearLayout.measureHorizontal(LinearLayout.java:1111) 
                        at android.widget.LinearLayout.onMeasure(LinearLayout.java:631) 
                        at android.view.View.measure(View.java:20158) 
                        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6328) 
                        at android.widget.FrameLayout.onMeasure(FrameLayout.java:194) 
                        at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:135) 
                        at android.view.View.measure(View.java:20158) 
                        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6328) 
                        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1464) 
                        at android.widget.LinearLayout.measureVertical(LinearLayout.java:747) 
                        at android.widget.LinearLayout.onMeasure(LinearLayout.java:629) 
                        at android.view.View.measure(View.java:20158) 
                        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6328) 
                        at android.widget.FrameLayout.onMeasure(FrameLayout.java:194) 
                        at android.view.View.measure(View.java:20158) 
                        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6328) 
                        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1464) 
                        at android.widget.LinearLayout.measureVertical(LinearLayout.java:747) 
                        at android.widget.LinearLayout.onMeasure(LinearLayout.java:629) 
                        at android.view.View.measure(View.java:20158) 
                        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6328) 
                        at android.widget.FrameLayout.onMeasure(FrameLayout.java:194) 
                        at com.android.internal.policy.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:3158) 
                        at android.view.View.measure(View.java:20158) 
                        at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2644) 
                        at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1599) 
                        at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1891) 
                        at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1487) 
                        at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7467) 
                        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:920) 
                        at android.view.Choreographer.doCallbacks(Choreographer.java:695) 
                        at android.view.Choreographer.doFrame(Choreographer.java:631) 
                        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:906) 
                        at android.os.Handler.handleCallback(Handler.java:739) 
                        at android.os.Handler.dispatchMessage(Handler.java:95) 
                        at android.os.Looper.loop(Looper.java:158) 
                        at android.app.ActivityThread.main(ActivityThread.java:7224) 
                        at java.lang.reflect.Method.invoke(Native Method) 
                        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230) 
                        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120) 

也许我会找出被保存我的数据库,在那里,并删除我无意中保存的条目并删除它。从现在开始,只要确保我实际上在保存价值,但如果有办法解决这个问题,我一定会很感激这些知识。

+0

请阅读例外...这是不言自明的。 – Selvin

回答

1

当我救了(什么),它结束了崩溃

,所以我觉得你list.getGrandTotal()没有任何价值或具有空字符串,它会导致NumberFormatException

之前,所以检查解析为浮点数:

String value = list.getGrandTotal(); 
if (value != null && value.length() > 0) { 
    sum = Float.valueOf(value) + sum; 
    } 
+0

当我将上面的代码输入到我的for循环中时,由于某些原因总计不能正确计算。我试着将3个条目放到我的数据库中,总数为8.75,9.06和3.75。每场比赛的总成绩分别为8.75,18.12和11.25。看来这些值正在乘以数据库中的位置编号。 –

+0

在之前的总显示ok ..? – rafsanahmad007

+0

尝试把'String value = list.getGrandTotal();'for循环之外.. – rafsanahmad007

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