我正在写一个简单的计算器，但不幸的是它没有用。
LogCat说错误发生在我的at android.view.View$1.onClick(View.java:2072)
：
activity_main.xml但我很遗憾地说我无法找到它。所以请帮助我。
<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"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<EditText
android:id="@+id/editText1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="54dp"
android:layout_marginTop="60dp"
android:ems="10" />
<EditText
android:id="@+id/editText2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/editText1"
android:layout_below="@+id/editText1"
android:layout_marginTop="74dp"
android:ems="10" />
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/editText1"
android:layout_alignParentTop="true"
android:layout_marginTop="38dp"
android:text="Input first number" />
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/editText2"
android:layout_below="@+id/editText1"
android:layout_marginTop="36dp"
android:text="Input 2nd number" />
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="functionCalculator"
android:layout_alignLeft="@+id/editText2"
android:layout_below="@+id/editText2"
android:layout_marginTop="26dp"
android:text="+"/>
<TextView
android:id="@+id/textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/button1"
android:layout_marginTop="28dp"
android:text="Your result here" />
<TextView
android:id="@+id/textView4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignTop="@+id/textView3"
android:layout_marginLeft="20dp"
android:layout_toRightOf="@+id/button1"
android:text="Result"
android:textAppearance="?android:attr/textAppearanceLarge" />
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/button1"
android:layout_alignRight="@+id/textView4"
android:text="-"
android:onClick="functionCalculator" />
</RelativeLayout>
：
ActivityMain.java package com.example.caculator;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends Activity {
EditText e1,e2;
TextView t1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
e1= (EditText)findViewById(R.id.editText1);
e2 = (EditText)findViewById(R.id.editText2);
t1 = (TextView)findViewById(R.id.textView4);
}
public void functionCalculator(View view) {
int number1 , number2 , result;
if (view.getId()==R.id.button1) {
number1 = Integer.parseInt(e1.getText().toString());
number2 = Integer.parseInt(e2.getText().toString());
result = number1+number2;
t1.setText(Integer.toString(result));
}
if (view.getId()==R.id.button2) {
number1 = Integer.parseInt(e1.getText().toString());
number2 = Integer.parseInt(e2.getText().toString());
result = number1-number2;
t1.setText(Integer.toString(result));
}
}
@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;
}
}
：
{{1}}
答案 0 :(得分：0)
我运行了您的代码，只要我将整数放在e1和e2中，就不会遇到任何问题。一旦我输入十进制数字，我就遇到了与你提到的完全相同的问题。这是因为您试图从输入中解析整数，这些整数可能并不总是成功并且将导致NumberFormatException。您应该编写代码，以便它不会崩溃，无论如何。假设您的用户是白痴。尝试下面的代码，它不应该崩溃：
public void functionCalculator(View view) {
try {
// Firstly checking for integers
int number1, number2;
number1 = Integer.parseInt(e1.getText().toString());
number2 = Integer.parseInt(e2.getText().toString());
if (view.getId() == R.id.button1)
t1.setText(Integer.toString(number1 + number2));
else if (view.getId() == R.id.button2)
t1.setText(Integer.toString(number1 - number2));
} catch (NumberFormatException e) {
float number1, number2;
try {
// Now checking for decimals
number1 = Float.parseFloat(e1.getText().toString());
number2 = Float.parseFloat(e2.getText().toString());
if (view.getId() == R.id.button1)
t1.setText(Float.toString(number1 + number2));
else if (view.getId() == R.id.button2)
t1.setText(Float.toString(number1 - number2));
} catch (NumberFormatException e2) {
// No numbers :(
Toast.makeText(this, "WTF! Enter number here you dingus!", Toast.LENGTH_SHORT).show();
}
}
}