java - AVD Eclipse “很遗憾，计算器已停止。” 新错误

Question

现在我的计算器应用程序出现了一个新问题，因此我可以打开应用程序，然后单击一系列按钮，例如 1 x 3 =

当我单击 ButtonEquals 按钮时，我得到“不幸的是，计算器已停止”。我似乎无法弄清楚为什么。

原始线程：在 Eclipse AVD 中，我收到“不幸的是，计算器已停止”。API 级别 16（修复了较早的问题）

MainActivity.Java

package com.papps.calculator;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;


public class MainActivity extends Activity {
    int num1 = 90;
    int num2 = 90;
    int op = 0;
    int ans = 0;

    TextView answer;

    Button ButtonEquals;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        answer = (TextView) findViewById(R.id.answer);
        ButtonEquals = (Button) findViewById(R.id.ButtonEquals);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }
    //ONE
    public void none(View v) {
        if(num1 == 90) {
            num1 = 1;
        }
        else if(num2 == 90) {
            num2 = 1;
         }
    }
    //TWO
    public void ntwo(View v) {
        if(num1 == 90) {
            num1 = 2;
        }
        else if(num2 == 90) {
            num2 = 2;
         }
    }
    //THREE
    public void nthree(View v) {
        if(num1 == 90) {
            num1 = 3;
        }
        else if(num2 == 90) {
            num2 = 3;
         }
    }
    //FOUR
    public void nfour(View v) {
        if(num1 == 90) {
            num1 = 4;
        }
        else if(num2 == 90) {
            num2 = 4;
         }
    }
    //FIVE
    public void nfive(View v) {
        if(num1 == 90) {
            num1 = 5;
        }
        else if(num2 == 90) {
            num2 = 5;
         }
    }
    //SIX
    public void nsix(View v) {
        if(num1 == 90) {
            num1 = 6;
        }
        else if(num2 == 90) {
            num2 = 6;
         }
    }
    //SEVEN
    public void nseven(View v) {
        if(num1 == 90) {
            num1 = 7;
        }
        else if(num2 == 90) {
            num2 = 7;
         }
    }
    //EIGHT
    public void neight(View v) {
        if(num1 == 90) {
            num1 = 8;
        }
        else if(num2 == 90) {
            num2 = 8;
         }
    }
    //NINE
    public void nnine(View v) {
        if(num1 == 90) {
            num1 = 9;
        }
        else if(num2 == 90) {
            num2 = 9;
         }
    }
    //ZERO
    public void nzero(View v) {
        if(num1 == 90) {
            num1 = 0;
        }
        else if(num2 == 90) {
            num2 = 0;
         }
    }
    //operators

    //MULTIPLY
    public void multiply(View v) {
        op = 1;
    }
    //Divide
    public void divide(View v) {
        op = 2;
    }
    //Add
    public void add(View v) {
        op = 3;
    }
    //Subtract
    public void subtract(View v) {
        op = 4;
    }

    //EQUALS
    //TextView answer = (TextView) findViewById(R.id.answer);
    //Button ButtonEquals = (Button) findViewById(R.id.ButtonEquals);
    public void equals(View v) {
        switch(op) {
        case 1 :
            answer.setText(num1 * num2);
        case 2 :
            answer.setText(num1 / num2);
        case 3 :
            answer.setText(num1 + num2);
        case 4 :
            answer.setText(num1 - num2);
        }
    }
}

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="97dp"
        android:layout_marginTop="16dp"
        android:text="@string/app_name"
        tools:context=".MainActivity" />

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/textView1"
        android:layout_marginLeft="14dp"
        android:layout_marginTop="15dp"
        android:text="1"
        android:onClick = "none" />

    <Button
        android:id="@+id/Button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/button1"
        android:layout_alignBottom="@+id/button1"
        android:layout_alignLeft="@+id/textView1"
        android:layout_marginLeft="15dp"
        android:text="2"
        android:onClick = "ntwo" />

    <Button
        android:id="@+id/Button3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/Button2"
        android:layout_alignBottom="@+id/Button2"
        android:layout_marginLeft="34dp"
        android:layout_toRightOf="@+id/Button2"
        android:text="3"
        android:onClick = "nthree" />

    <Button
        android:id="@+id/Button4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/button1"
        android:layout_below="@+id/button1"
        android:layout_marginTop="36dp"
        android:text="4"
        android:onClick = "nfour" />

    <Button
        android:id="@+id/Button5"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/Button4"
        android:layout_alignBottom="@+id/Button4"
        android:layout_alignLeft="@+id/Button2"
        android:text="5"
        android:onClick = "nfive" />

    <Button
        android:id="@+id/Button6"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/Button5"
        android:layout_alignBottom="@+id/Button5"
        android:layout_alignLeft="@+id/Button3"
        android:text="6" 
        android:onClick = "nsix" />

    <Button
        android:id="@+id/Button7"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/Button4"
        android:layout_centerVertical="true"
        android:text="7" 
        android:onClick = "nseven" />

    <Button
        android:id="@+id/Button8"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_toLeftOf="@+id/Button3"
        android:text="8" 
        android:onClick = "neight" />

    <Button
        android:id="@+id/Button9"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/Button6"
        android:layout_centerVertical="true"
        android:text="9"
        android:onClick = "nnine" />

    <Button
        android:id="@+id/Button0"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/Button8"
        android:layout_below="@+id/Button8"
        android:layout_marginTop="29dp"
        android:text="0"
        android:onClick = "nzero" />

    <Button
        android:id="@+id/ButtonM"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:text="X"
        android:onClick = "multiply" />

    <Button
        android:id="@+id/ButtonD"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_toRightOf="@+id/Button7"
        android:text="/"
        android:onClick = "divide" />

    <Button
        android:id="@+id/ButtonS"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_toRightOf="@+id/textView1"
        android:text="-"
        android:onClick = "subtract" />

    <Button
        android:id="@+id/ButtonA"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_marginLeft="14dp"
        android:layout_toRightOf="@+id/ButtonS"
        android:text="+"
        android:onClick = "add" />

    <TextView
        android:id="@+id/answer"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/ButtonD"
        android:layout_marginBottom="24dp"
        android:layout_toRightOf="@+id/ButtonD"
        android:text="Answer"
        android:textAppearance="?android:attr/textAppearanceLarge" />

    <Button
        android:id="@+id/ButtonEquals"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/answer"
        android:layout_alignBottom="@+id/answer"
        android:layout_toLeftOf="@+id/Button0"
        android:text="="
        android:onClick = "equals" />

</RelativeLayout>

Answer 1

你还没有发布你的 LogCat 堆栈跟踪，所以我们只能假设。

你可能想试试

 public void equals(View v) {
    switch(op) {
    case 1 :
        answer.setText(""+(num1 * num2));
    case 2 :
        answer.setText(""+(num1 / num2));
    case 3 :
        answer.setText(""+(num1 + num2));
    case 4 :
        answer.setText(""(num1 - num2));
    }
}

我认为 TextView 没有正确更新。还要确保改变num1并num2成为double价值观。这样你的分裂就不会被截断。