Android似乎没有正确计算

-2

基本上，有一个文本字段，用户可以输入用餐的小计。然后，当它们完成时，done方法应该取最终字段值，并将其乘以小计值，以便总计包含这两个数据。但是，当我点击完成按钮时，结果实际上总是等于小计，并且小费始终被忽略。下面是代码：Android似乎没有正确计算

public class MainActivity extends Activity implements OnRatingBarChangeListener { 

    // Testing Stuff to show the rating value, will need to use later for maths 
    static RatingBar rb; 
    TextView tipsTV; 

    ImageView greyPlus, greyMinus, greyPlus2, greyMinus2; 

    TextView peopleDiningTV, peopleDiningTitle; 
    int peopleDining = 2; 

    TextView tipValue; 
    int tipValueInt = 10; 

    TextView subtotal, total; 
    TextView subtotalTitle, totalTitle; 

    TextView epp, eppTitle; 
    Button done; 

    // Elements for hiding and such 
    static RelativeLayout rl; 
    static Button settingsButton; 

    public static int rating = 3; 

    // The Image used as the DropDown button, Rotate code below 
    ImageView dropDownButton; 

    Boolean hasRotated = false; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 

     setContentView(R.layout.activity_main); 
     dropDownButton = (ImageView) findViewById(R.id.dropDownButton); 
     rb = (RatingBar) findViewById(R.id.ratingBar1); 
     rb.setRating(rating); 

     tipsTV = (TextView) findViewById(R.id.textView2); 

     tipValue = (TextView) findViewById(R.id.tipText); 

     greyPlus = (ImageView) findViewById(R.id.greyPlus); 
     greyMinus = (ImageView) findViewById(R.id.greyMinus); 

     greyPlus2 = (ImageView) findViewById(R.id.greyPlus2); 
     greyMinus2 = (ImageView) findViewById(R.id.greyMinus2); 

     peopleDiningTV = (TextView) findViewById(R.id.textViewPeople); 
     peopleDiningTitle = (TextView) findViewById(R.id.TextView02); 

     subtotal =(TextView) findViewById(R.id.subtotalText); 
     subtotalTitle =(TextView) findViewById(R.id.subtotalTitle); 

     total =(TextView) findViewById(R.id.totalText); 
     totalTitle =(TextView) findViewById(R.id.totalTitle); 

     epp = (TextView) findViewById(R.id.eppText); 
     eppTitle = (TextView) findViewById(R.id.eppTitle); 

     done = (Button) findViewById(R.id.buttonDone); 

     greyPlus.setOnClickListener(new OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       tipValueInt++; 
       tipValue.setText(tipValueInt + "%"); 
      } 
     }); 
     greyMinus.setOnClickListener(new OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       if (tipValueInt >= 1) { 
        tipValueInt--; 
        tipValue.setText(tipValueInt + "%"); 
       } 
       if(tipValueInt == 0){ 
        tipValue.setText("No Tip."); 
       } 
      } 
     }); 

     greyPlus2.setOnClickListener(new OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       peopleDining++; 
       peopleDiningTV.setText(peopleDining + ""); 
      } 
     }); 
     greyMinus2.setOnClickListener(new OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       if (peopleDining > 1) { 
        peopleDining--; 
        peopleDiningTV.setText(peopleDining + ""); 
       } 
      } 
     }); 
    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.main, menu); 
     return true; 
    } 

    FragmentManager fm = getFragmentManager(); 
    QuizFragment qf = new QuizFragment(); 

    public void dropDown(View view) { 
     if (hasRotated == false) { 
      FragmentTransaction ft = fm.beginTransaction(); 
      ft.setCustomAnimations(android.R.animator.fade_in, 
        android.R.animator.fade_out); 
      dropDownButton.setRotation(90); 
      ft.add(R.id.quizFragment, qf); 
      ft.show(qf); 
      ft.commit(); 
      hasRotated = true; 

      // Hiding Elements, so they don't show through the fragment 
      tipsTV.setVisibility(View.INVISIBLE); 
      greyPlus.setVisibility(View.INVISIBLE); 
      greyMinus.setVisibility(View.INVISIBLE); 
      tipValue.setVisibility(View.INVISIBLE); 

      greyPlus2.setVisibility(View.INVISIBLE); 
      greyMinus2.setVisibility(View.INVISIBLE); 
      peopleDiningTV.setVisibility(View.INVISIBLE); 
      peopleDiningTitle.setVisibility(View.INVISIBLE); 

      subtotal.setVisibility(View.INVISIBLE); 
      subtotalTitle.setVisibility(View.INVISIBLE); 
      total.setVisibility(View.INVISIBLE); 
      totalTitle.setVisibility(View.INVISIBLE); 

      epp.setVisibility(View.INVISIBLE); 
      eppTitle.setVisibility(View.INVISIBLE); 

      done.setVisibility(View.INVISIBLE); 
     } else if (hasRotated == true) { 
      FragmentTransaction ft = fm.beginTransaction(); 
      ft.setCustomAnimations(android.R.animator.fade_out, 
        android.R.animator.fade_out); 
      dropDownButton.setRotation(0); 
      hasRotated = false; 
      ft.remove(qf); 
      ft.commit(); 

      // Hiding Elements, so they don't show through the fragment 
      tipsTV.setVisibility(View.VISIBLE); 
      greyPlus.setVisibility(View.VISIBLE); 
      greyMinus.setVisibility(View.VISIBLE); 
      tipValue.setVisibility(View.VISIBLE); 

      greyPlus2.setVisibility(View.VISIBLE); 
      greyMinus2.setVisibility(View.VISIBLE); 
      peopleDiningTV.setVisibility(View.VISIBLE); 
      peopleDiningTitle.setVisibility(View.VISIBLE); 

      subtotal.setVisibility(View.VISIBLE); 
      subtotalTitle.setVisibility(View.VISIBLE); 
      total.setVisibility(View.VISIBLE); 
      totalTitle.setVisibility(View.VISIBLE); 

      epp.setVisibility(View.VISIBLE); 
      eppTitle.setVisibility(View.VISIBLE); 

      done.setVisibility(View.VISIBLE); 
     } 
    } 

    public void openSettings(View view) { 
     Intent intent = new Intent(this, SettingsActivity.class); 
     startActivity(intent); 
    } 

    @Override 
    public void onRatingChanged(RatingBar ratingBar, float rating, 
      boolean fromTouch) { 

    } 
    public void done(View view){ 
     int subtotalCost = Integer.parseInt(subtotal.getText().toString()); 
     int tip = tipValueInt/100; 
     int totalCost = (subtotalCost * tip) + subtotalCost; 
     total.setText(totalCost+""); 
    } 
}

来源

2014-10-03 Dtroll MC

不要在这里粘贴整个代码，只显示您的问题的相关部分，这使得更容易发现错误 – nem035 2014-10-03 23:13:01

Android *确实*做数学“正确”。因此，它是代码中的一个错误 - 使用调试器观察* input *，* state *和* output *来清除“不工作”意味着什么并隔离最小测试用例。（也使用IDE - 例如Eclipse - 与观察结果无关。） – user2864740 2014-10-03 23:43:11

你永远不会把一个OnClickListener，以便您的点击都只是忽略按钮变量done，这就是为什么值不会改变。您应该添加监听器，然后在onClick()中调用您的done()方法。您还应该删除参数done()，因为您根本没有使用它。

// ... 
done = (Button) findViewById(R.id.buttonDone); 
// add listener 
done.setOnClickListener(new OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      done(); 
     } 
    }); 
// ...

你或许应该改变方法done()的名称displayResult()或更有意义的事情，而不是类似命名done您的按钮变量。实际上，您应该将大多数变量的名称更改为更清楚地描述变量用途的名称。例如，可变done表示该按钮可以像btnDone ...

来源

2014-10-03 23:19:34 nem035

什么？我完全不明白。 XML中的onClick方法应该工作... – 2014-10-03 23:36:25

您已经声明totalCost为int。因此，如果(subtotalCost * tip)小于1，则totalCost = subtotalCost。尝试使用floats而不是ints（如果适用）。

来源

2014-10-03 23:31:55 Onik

Android似乎没有正确计算

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