合計を得るためにeditText値を更新する

Question

私はそれぞれのデータに従って更新したいEditTextフィールドを複数持っていますので、私はaddTextChangedListenerを使っています。私の目標は、2つのEditText値の合計を取得し、その答えを別のEditTextに表示することです。しかし、私はまた、3番目のEditTextと最初の2つのうちの1つの違いを最初のものに表示しようとしています。だから、amountreceived = totalprice + tip、私はそれに応じて更新したいだけでなく、ユーザーが受信した合計価格と金額にデータを入力した場合、私はtip = amountreceived - totalpriceになりたいと思います。次のように

私のコードは次のとおりです。

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.order_details); 

    eAmountReceived = (EditText) findViewById(R.id.amountReceived); 
    eTotalCost = (EditText) findViewById(R.id.orderTotal); 
    eTip = (EditText) findViewById(R.id.tip); 
    eMileage = (EditText) findViewById(R.id.mileage); 
    eGrandTotal = (EditText) findViewById(R.id.grandTotal); 

    eAmountReceived.addTextChangedListener(this); 
    eTip.addTextChangedListener(this); 

    // eTotalCost.addTextChangedListener(this); 
    // eMileage.addTextChangedListener(this); 
    // eGrandTotal.addTextChangedListener(this); 

    eTip.addTextChangedListener(new TextWatcher() 
    { 
     @Override 
     public void beforeTextChanged(CharSequence s, int start, 
             int count, int after){} 

     @Override 
     public void onTextChanged(CharSequence s, int start, 
            int before, int count) 
     { 
      if(eTip.isFocused() && isSet(eAmountReceived) && isSet(eTotalCost)) 
      { 
       updateSubtract(); 
      } 
     } 

     @Override 
     public void afterTextChanged(Editable s){} 
    }); 

    eAmountReceived.addTextChangedListener(new TextWatcher() 
    { 
     @Override 
     public void beforeTextChanged(CharSequence s, int start, 
             int count, int after){} 

     @Override 
     public void onTextChanged(CharSequence s, int start, 
            int before, int count) 
     { 
      if(eAmountReceived.isFocused() && isSet(eTotalCost) && isSet(eTip)) 
      { 
       updateAdd(); 
      } 
     } 

     @Override 
     public void afterTextChanged(Editable s){} 
    }); 
} 

private void updateAdd() 
{ 
    double dTotalCost = Double.valueOf(eTotalCost.getText().toString()); 
    double dTip = Double.valueOf(eTip.getText().toString()); 
    eAmountReceived.setText(String.valueOf(dTotalCost + dTip)); 
} 

private void updateSubtract() 
{ 
    double dAmountReceived = Double.valueOf(eAmountReceived.getText().toString()); 
    double dTotalCost = Double.valueOf(eTotalCost.getText().toString()); 
    eTip.setText(String.valueOf(dAmountReceived - dTotalCost)); 
} 

private boolean isSet(EditText editText) 
{ 
    return !editText.getText().toString().matches(""); 
} 

@Override 
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {} 

@Override 
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) 
{ 
    updateAdd(); 
    updateSubtract(); 
} 

@Override 
public void afterTextChanged(Editable editable) {} 

public void onClick(View view) 
{ 

    name = (EditText) findViewById(R.id.name); 
    number = (EditText) findViewById(R.id.number); 
    address = (EditText) findViewById(R.id.address); 
    orderTotal = (EditText) findViewById(R.id.orderTotal); 
    amountReceived = (EditText) findViewById(R.id.amountReceived); 
    tip = (EditText) findViewById(R.id.tip); 
    mileage = (EditText) findViewById(R.id.mileage); 
    grandTotal = (EditText) findViewById(R.id.grandTotal); 

    String cName = name.getText().toString(); 
    String num = number.getText().toString(); 
    String cAddress = address.getText().toString(); 
    String cOrderTotal = orderTotal.getText().toString(); 
    String cAmountReceived = amountReceived.getText().toString(); 
    String cTip = tip.getText().toString(); 
    String cMileage = mileage.getText().toString(); 
    String cGrandTotal = grandTotal.getText().toString(); 


    int id = db.addContact(new PhoneBook(cName, num, cAddress, cOrderTotal, 
              cAmountReceived, cTip, cMileage, cGrandTotal)); 
    contactList.add(new PhoneBook(id, cName, num, cAddress, cOrderTotal, 
            cAmountReceived, cTip, cMileage, cGrandTotal)); 
    adapter.notifyDataSetChanged(); 

    Toast.makeText(getApplicationContext(), "Entry Successfully Created.", Toast.LENGTH_LONG).show(); 
} 

私はこれが働くだろうと思ったが、私は、データを入力するためのEditTextフィールドをクリックすると、アプリがクラッシュします。私もlogcatにエラーがないので、何が間違っているのか分かりません。どんな助けでも大歓迎です！

EDIT：次のようにlogcatエラーがある：

FATAL EXCEPTION: main 


    Process: com.example.boley.databaseexample, PID: 2949 
          java.lang.NumberFormatException: Invalid double: "" 
at java.lang.StringToReal.invalidReal(StringToReal.java:63) 
at java.lang.StringToReal.parseDouble(StringToReal.java:267) 
at java.lang.Double.parseDouble(Double.java:301) 
at java.lang.Double.valueOf(Double.java:338) 
at com.example.boley.databaseexample.OrderDetails.updateAdd(OrderDetails.java:193) 
at com.example.boley.databaseexample.OrderDetails.onTextChanged(OrderDetails.java:215) 
at android.widget.TextView.sendOnTextChanged(TextView.java:7991) 
at android.widget.TextView.handleTextChanged(TextView.java:8053) 
at android.widget.TextView$ChangeWatcher.onTextChanged(TextView.java:10157) 
at android.text.SpannableStringBuilder.sendTextChanged(SpannableStringBuilder.java:1033) 
at android.text.SpannableStringBuilder.replace(SpannableStringBuilder.java:559) 
at android.text.SpannableStringBuilder.replace(SpannableStringBuilder.java:492) 
at android.text.SpannableStringBuilder.replace(SpannableStringBuilder.java:491) 
at android.text.method.NumberKeyListener.onKeyDown(NumberKeyListener.java:121) 
at android.widget.TextView.doKeyDown(TextView.java:6098) 
at android.widget.TextView.onKeyDown(TextView.java:5911) 
at android.view.KeyEvent.dispatch(KeyEvent.java:2640) 
at android.view.View.dispatchKeyEvent(View.java:9234) 
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1640) 
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1640) 
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1640) 
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1640) 
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1640) 
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1640) 
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1640) 
at com.android.internal.policy.PhoneWindow$DecorView.superDispatchKeyEvent(PhoneWindow.java:2395) 
at com.android.internal.policy.PhoneWindow.superDispatchKeyEvent(PhoneWindow.java:1727) 
at android.app.Activity.dispatchKeyEvent(Activity.java:2725) 
at android.support.v7.app.AppCompatActivity.dispatchKeyEvent(AppCompatActivity.java:543) 
at android.support.v7.view.WindowCallbackWrapper.dispatchKeyEvent(WindowCallbackWrapper.java:53) 
at android.support.v7.app.AppCompatDelegateImplBase$AppCompatWindowCallbackBase.dispatchKeyEvent(AppCompatDelegateImplBase.java:315) 
at com.android.internal.policy.PhoneWindow$DecorView.dispatchKeyEvent(PhoneWindow.java:2310) 
at android.view.ViewRootImpl$ViewPostImeInputStage.processKeyEvent(ViewRootImpl.java:4127) 
at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:4089) 
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3642) 
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3695) 
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3661) 
at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:3787) 
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3669) 
at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:3844) 
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3642) 
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3695) 
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3661) 
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3669) 
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3642) 
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3695) 
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3661) 
at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:3820) 
at android.view.ViewRootImpl$ImeInputStage.onFinishedInputEvent(ViewRootImpl.java:3981) 
at android.view.inputmethod.InputMethodManager$PendingEvent.run(InputMethodManager.java:2253) 
at android.view.inputmethod.InputMethodManager.invokeFinishedInputEventCallback(InputMethodManager.java:1874) 
at android.view.inputmethod.InputMethodMan 

Answer 1

あなたの問題は、あなたがこのような何かにupdateSubtract()とupdateAdd()を変更する場合は、あなたのdouble値

private void updateSubtract() { 
    double dAmountReceived = Double.valueOf(eAmountReceived.getText().toString()); 
    double dTotalCost = Double.valueOf(eTotalCost.getText().toString()); 
    eTip.setText(String.valueOf(dAmountReceived - dTotalCost)); 
} 

を解析する方法で、ここにありますあなたの問題を解決するはずです。私はテストなしでこれを書きましたが、私はそれがうまくいくはずです。

private void updateSubtract() { 
    String amountReceivedText = eAmountReceived.getText().toString(); 
    String totalCostText = eTotalCost.getText().toString(); 

    if (!TextUtils.isEmpty(amountReceivedText) && !TextUtils.isEmpty(totalCostText)) {} 
     float dAmountReceived = Float.parseFloat(amountReceivedText); 
     float dTotalCost = Float.parseFloat(totalCostText); 
     float dTipValue = dAmountReceived - dTotalCost; 
     eTip.setText(String.valueOf(dTipValue)); 
    } 
} 

また、あなたは必ずそれがFloat値であることを確認またはそれが唯一の入力としてfloat型の値をとるように、あなたのEditTextにinputTypeを適用するためにeAmountReceivedとtotalCostTextの入力を確認するのいずれかのことを確認してください。私は後者を好むのは、EditTextに焦点を合わせるときに数字だけのキーボードを与えるからです。