Question

Good Day,

I am new to android and using Eclipse 3.7.2. I have been following examples on the net (the so-called “add two numbers” examples but, after discovering that AbsoluteLayout is deprecated, I am using RelativeLayout and basically going from scratch. The app basically is supposed to take two numbers (how far a guy went and how much he is paid per mile) and pop out total pay.

The app compiles fine and starts up in the emulator. I get excited! Pop in 2 numbers and hit the button. Nothing. I look and see that there’s no errors happening.

Am I missing something with my button listener? Here is the Java code I’ve put in (updated 5:27pm 10.31.2012):

package com.example.wing_it;

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

public class MainActivity extends Activity {
EditText mile,driver;
Button button1;
TextView tv;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mile= (EditText) findViewById(R.id.mile);
    button1 = (Button) findViewById(R.id.button1);
    tv = (TextView) findViewById(R.id.pay);
    driver= (EditText) findViewById(R.id.driver);
    button1.setOnClickListener((OnClickListener) this);
    }


public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_main, menu);
    return true;
}
class clicker implements Button.OnClickListener
{
public void onClick(View v) {
    // TODO Auto-generated method stub
    {
        String a,b;
        Integer vis;
        a = mile.getText().toString();
        b = driver.getText().toString();
        vis = Integer.parseInt(a)*Integer.parseInt(b);
        tv.setText(vis.toString());
        }
    }
}       
}

The XML code is as such:

<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:text="@string/miles"
    android:textAppearance="?android:attr/textAppearanceMedium" />

<TextView
    android:id="@+id/textView2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_below="@+id/textView1"
    android:layout_marginTop="40dp"
    android:text="@string/paypermile"
    android:textAppearance="?android:attr/textAppearanceMedium" />

<Button
    android:id="@+id/button1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/textView2"
    android:layout_marginLeft="52dp"
    android:layout_marginTop="62dp"
    android:layout_toRightOf="@+id/textView2"
    android:text="@string/compute" />

<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="46dp"
    android:text="@string/pay"
    android:textAppearance="?android:attr/textAppearanceMedium" />

<EditText
    android:id="@+id/mile"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
    android:layout_alignParentTop="true"
    android:layout_toRightOf="@+id/button1"
    android:ems="10"
    android:inputType="numberDecimal" >

    <requestFocus />
</EditText>

<EditText
    android:id="@+id/driver"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/textView2"
    android:layout_alignBottom="@+id/textView2"
    android:layout_alignLeft="@+id/mile"
    android:layout_alignParentRight="true"
    android:ems="10"
    android:inputType="numberDecimal" />

<TextView
    android:id="@+id/pay"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/textView3"
    android:layout_alignBottom="@+id/textView3"
    android:layout_alignParentRight="true"
    android:text="@string/totalpay"
    android:textAppearance="?android:attr/textAppearanceLarge" />

</RelativeLayout>

Here is the manifest:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.wing_it"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
    android:minSdkVersion="7"
    android:targetSdkVersion="15" />

<application
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".MainActivity"
        android:label="@string/title_activity_main" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
 </application>

</manifest>

I have the value of the result textview set to nothing (just a blank) in the strings.xml. It was set to ‘0’ and I removed that to see if it would make a difference. Still, nothing.

Is there something I am overlooking here? Thank you for looking. 🙂

Answer 1

    public class MainActivity extends Activity implements OnClickListener {

    public void onCreate() {
     button1 = (Button) findViewById(R.id.button1);
     button1.setOnClickListener(this);
    }

    public void onClick(View view) {
       // code here
    }

it’s hard to read your code, but this should work (sorry if i have spelling errors, i cannot cut/paste from my code (on another machine)