Question

I’m a bit confused, I set up my app as a simple converter but it isn’t working. My log says it has to do with myclickhandler, but I’m not sure where to go with that.

  package hmdywifinal.com;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
 import android.widget.ImageButton;
import android.widget.TextView;

public class Butterfliesstart extends Activity {
private ImageButton ConvertButterflies = null;
private ImageButton Butterfliesstart1 = null;
private EditText YourWeight = null;
private TextView Output = null;
 /** Called when the activity is first created. */
   @Override
public void onCreate(Bundle icicle) {
    super.onCreate(icicle);
    setContentView(R.layout.butterfliesstart);

    //GO BACK
        ImageButton Butterfliesstart1 =      (ImageButton)findViewById(R.id.testbutton2);
        Butterfliesstart1.setOnClickListener(new View.OnClickListener() {
            public void onClick(View argo) {
                setResult(RESULT_OK);
                finish();
            };
        });

    //Set IDS
        ImageButton ConvertButterflies = (ImageButton)findViewById(R.id.testbutton1);


    //Set Values
    class ToButterflies implements View.OnClickListener
    {
        public void onClick(View v)
        {
            convertToButterflies();
        }
        private void convertToButterflies()
        {
            String ButterflyString = YourWeight.getText().toString();
            double f = Double.parseDouble(ButterflyString);
            double c = 5.0/9.0 * (f - 32.0); 
            EditText YourWeight = (EditText)findViewById(R.id.editText1);
            Output.setText(String.valueOf(c));      

        }
    }
    Output = new EditText(this);
    EditText Output = (EditText)findViewById(R.id.editText2);

    //Initialize
    Butterfliesstart1 = new ImageButton(this);
    ConvertButterflies = new ImageButton(this);

    YourWeight = new EditText (this);

XML:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView  
android:layout_width="fill_parent" 
android:layout_height="wrap_content" 
android:text="Butterfliesstart"></TextView>


<EditText
    android:id="@+id/editText1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >

    <requestFocus />
</EditText>
 <EditText
    android:id="@+id/editText2"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >

    <requestFocus />
</EditText>

<ImageButton 
android:text="and back."  
android:src="@drawable/dirtbutton"
android:id="@+id/testbutton2" 
android:layout_width="wrap_content" 
android:layout_height="wrap_content"
android:onClick=""
>
</ImageButton>
<ImageButton
android:src="@drawable/bumblebees"
android:id="@+id/testbutton1" 
android:layout_width="wrap_content" 
android:layout_height="wrap_content"
android:onClick="myClickHandler"
> 
</ImageButton>
</LinearLayout>

After I press the button to convert it, it force closes. Did I miss anything in the code?

Answer 1

Unless you haven’t posted all of it, your ImageButton with the id of testbutton1 has an android:onClick defined as myClickHandler but you haven’t defined that method. That’ll crash quite successfully every time you press it.

I agree with JoxTraex, though… this is pretty easy stuff to track if you take the time to learn to use the tools you have. Read up on DDMS.