Java 我想计算数字并在android下一个屏幕布局的文本框中显示结果

main activity.java

在单击按钮时调用calculator void方法时未获得结果。我希望在reulst_页面布局中创建的两个文本视图中发布我的结果

activity_main.xml

result_page.xml

---

目前，您正在MainActivity.java中执行名为ResultPage的第二个活动calculate，但该活动不存在，因此无法更改其视图EditText3和editText4

为了将数据传递给另一个活动，您应该用一些额外的数据填充您的意图，然后在您的ResultPage活动的onCreate中，您将获得基本的额外数据

编辑

MainActivity.java

onCreate中的ResultPage.java

---

它无法工作。在mainactivity.java处获取一个错误，指出无法使用amount3和amount4解析意图。这两个变量从未在resultpage.java中使用过。因此它显示出错误。还有其他解决办法吗

package abhilmohan.blogspot.com;

import android.R.string;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.app.ActionBar;
import android.content.Intent;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.os.Bundle;

public class MainActivity extends ActionBarActivity {
EditText amount1;
EditText amount2;
EditText amount3;
EditText amount4;
Button calculate;
double w=0;
double x=0;
double y=0;
double z=0;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


    ActionBar bar= getActionBar();
    bar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#ff0000")));

}
public void initcontrols() {
    amount1=(EditText)findViewById(R.id.editText1);
    amount2=(EditText)findViewById(R.id.editText2);
    amount3=(EditText)findViewById(R.id.editText3);
    amount4=(EditText)findViewById(R.id.editText4);
    calculate=(Button)findViewById(R.id.button1);
}
public void calculate() {
    w=Double.parseDouble(amount1.getText().toString());
    x=Double.parseDouble(amount2.getText().toString());
    y=w/12;
    amount3.setText(Double.toString(y));
    z=w*x/100;
    amount4.setText(Double.toString(z));
}
public void gotoactivity (View v) {
    Intent intent = new Intent(this,ResultPage.class);
        calculate();
    startActivity(intent);
}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/background"
android:gravity="left"
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="abhilmohan.blogspot.com.MainActivity" >

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/textView1"
        style="@style/text_style"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="40dp"
        android:layout_marginRight="40dp"
        android:text="@string/ctc"
        android:textAppearance="?android:attr/textAppearanceLarge" />

    <EditText
        android:id="@+id/editText1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="75dp"
        android:layout_marginLeft="30dp"
        android:layout_marginRight="20dp"
        android:layout_marginTop="-15dp"
        android:inputType="number"
        android:background="@drawable/rounded_edit_text"
        android:ems="10"
        android:padding="20dp"
        android:paddingBottom="50dp"
        android:textColor="#000000" />

    <TextView
        android:id="@+id/textView2"
        style="@style/text_style"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="90dp"
        android:layout_marginLeft="40dp"
        android:layout_marginTop="-30dp"
        android:text="@string/TDS"
        android:textAppearance="?android:attr/textAppearanceLarge" />

    <EditText
        android:id="@+id/editText2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="30dp"
        android:layout_marginTop="-70dp"
        android:background="@drawable/rounded_edit_text"
        android:inputType="number"
        android:ems="10"
        android:padding="20dp"
        android:paddingBottom="50dp" >

        <requestFocus />
    </EditText>

    <Button
        android:id="@+id/button1"
        android:layout_width="177dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_marginTop="60dp"
        android:background="@drawable/button_style"
        android:text="@string/ok"
        android:textColor="#ffffff"
        android:onClick="gotoactivity" />
</LinearLayout>
</RelativeLayout>

 package abhilmohan.blogspot.com;

import android.support.v7.app.ActionBarActivity;
import android.view.MenuItem;
import android.app.ActionBar;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.os.Bundle;

public class ResultPage extends ActionBarActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.result_page);

    getActionBar().setDisplayHomeAsUpEnabled(true);
    ActionBar bar= getActionBar();
    bar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#ff0000")));
    }
@Override
public boolean onOptionsItemSelected(MenuItem item) {
    if(item.getItemId()== android.R.id.home)
    {
        finish();
    }
    return super.onOptionsItemSelected(item);
}

}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/background"
    android:orientation="vertical" >

<TextView
    android:id="@+id/textView1"
    style="@style/text_style"
    android:layout_width="wrap_content"         
    android:layout_height="wrap_content"
    android:layout_margin="40dp"
    android:layout_marginRight="40dp"
    android:text="@string/amount"
    android:textAppearance="?android:attr/textAppearanceLarge" />

<EditText
    android:id="@+id/editText3"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginBottom="75dp"
    android:layout_marginLeft="30dp"
    android:layout_marginRight="20dp"
    android:layout_marginTop="-15dp"
    android:background="@drawable/rounded_edit_text"
    android:ems="10"
    android:inputType="number"
    android:padding="20dp"
    android:paddingBottom="50dp"
    android:textColor="#000000"
    android:clickable="false"
    android:cursorVisible="false"
    android:focusable="false"
    android:focusableInTouchMode="false" />

<TextView
    android:id="@+id/textView2"
    style="@style/text_style"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginBottom="90dp"
    android:layout_marginLeft="40dp"
    android:layout_marginTop="-30dp"
    android:text="@string/tdsamount"
    android:textAppearance="?android:attr/textAppearanceLarge" />

<EditText
    android:id="@+id/editText4"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="30dp"
    android:layout_marginTop="-70dp"
    android:background="@drawable/rounded_edit_text"
    android:ems="10"
    android:inputType="number"
    android:padding="20dp"
    android:paddingBottom="50dp" 
    android:clickable="false"
    android:cursorVisible="false"
    android:focusable="false"
    android:focusableInTouchMode="false" >
    <requestFocus />
</EditText>

<Button
    android:id="@+id/button2"
    android:layout_width="177dp"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:layout_marginTop="60dp"
    android:background="@drawable/button_style"
    android:text="@string/rate"
    android:textColor="#ffffff" />

</LinearLayout>

public void gotoactivity (View v) {
    calculate();
    Intent intent = new Intent(this, ResultPage.class);
    intent.putExtra("AMOUNT_3", y);
    intent.putExtra("AMOUNT_4", z);
    startActivity(intent);
}

Bundle extras = getIntent().getExtras();
if (extras != null) {
    int amount3 = extras.getInt("AMOUNT_3");
    int amount4 = extras.getInt("AMOUNT_4");
}