我在 Eclipse 中没有收到任何错误。（这只是一个部分应用程序，我只为第一个“添加”按钮功能编码。）请在这里帮忙，因为我的应用程序在输入值并单击添加按钮后崩溃。这是我的代码：-
package ajay.calculator;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
EditText box1 = (EditText)findViewById(R.id.box_1);
EditText box2 = (EditText)findViewById(R.id.box_2);
}
public void addNumbers(EditText box1,EditText box2){
double a,b;
String str,str2 = new String();
str = box1.getText().toString();
str2 = box2.getText().toString();
a = Double.parseDouble(str);
b = Double.parseDouble(str2);
Log.d(box1.getText().toString(),"TAG");
Intent intent1 = new Intent(this,Result.class);
intent1.putExtra("first_number", a);
intent1.putExtra("second number", b);
startActivity(intent1);
}
public void multiplyNumbers(EditText box1,EditText box2){
double a,b;
String str,str2 = new String();
str = box1.getText().toString();
str2 = box2.getText().toString();
a = Double.parseDouble(str);
b = Double.parseDouble(str2);
Intent intent1 = new Intent(this,Result.class);
intent1.putExtra("first_number", a);
intent1.putExtra("second number", b);
startActivity(intent1);
}
public void subtractNumbers(EditText box1,EditText box2){
double a,b;
String str,str2 = new String();
str = box1.getText().toString();
str2 = box2.getText().toString();
a = Double.parseDouble(str);
b = Double.parseDouble(str2);
Intent intent1 = new Intent(this,Result.class);
intent1.putExtra("first_number", a);
intent1.putExtra("second number", b);
startActivity(intent1);
}
public void divideNumbers(EditText box1,EditText box2){
double a,b;
String str,str2 = new String();
str = box1.getText().toString();
str2 = box2.getText().toString();
a = Double.parseDouble(str);
b = Double.parseDouble(str2);
Intent intent1 = new Intent(this,Result.class);
intent1.putExtra("first_number", a);
intent1.putExtra("second number", b);
startActivity(intent1);
}
}
and the second activity is as follows:-
package ajay.calculator;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
import android.support.v4.app.NavUtils;
public class Result extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Intent intent1 = getIntent();
double x = intent1.getDoubleExtra("first_number", 0.0);
double y = intent1.getDoubleExtra("second number", 0.0);
TextView tview = (TextView)findViewById(R.id.text1);
tview.setText("The result is " + x+y);
setContentView(tview);
}
}
我的 xml 文件：-
1) 主要
<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" >
<EditText
android:id="@+id/box_1"
android:hint="@string/enter_no"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="30dp"
android:ems="10"
android:inputType="numberDecimal"
>
</EditText>
<EditText
android:id="@+id/box_2"
android:hint="@string/enter_no"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/box_1"
android:layout_centerHorizontal="true"
android:ems="10"
android:inputType="numberDecimal"
/>
<Button
android:id="@+id/button1"
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/box_2"
android:layout_below="@+id/box_2"
android:layout_marginTop="47dp"
android:text="@string/func_add"
android:onClick="addNumbers" />
<Button
android:id="@+id/button2"
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/button1"
android:layout_alignRight="@+id/box_2"
android:text="@string/func_mult"
android:onClick="multiplyNumbers" />
<Button
android:id="@+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignRight="@+id/button1"
android:layout_below="@+id/button1"
android:layout_marginTop="56dp"
android:text="@string/func_divide"
android:onClick="divideNumbers" />
<Button
android:id="@+id/button4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/button3"
android:layout_alignBottom="@+id/button3"
android:layout_alignRight="@+id/button2"
android:text="@string/func_subtract"
android:onClick="subtractNumbers"/>
<TextView
android:id="@+id/text1"
android:hint="@string/result"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
/>
</RelativeLayout>
2）第二个活动的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/text1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:text="@string/hello_world"
tools:context=".Result" />
</RelativeLayout>