CODEWITHSUNDEEP
javaandroid
JWDurbin
JWDurbin

Reputation: 11

android.widget.Button cannot be cast to android.view.View$OnKeyListener

Could someone please explain why I am getting this error?

Java.lang.ClassCastException: android.widget.Button cannot be cast to     android.view.View$OnKeyListener

Below is the java code. I am trying to follow a tutorial and I can't get it started. The RAZR emulator only shows Unfortunately JimYamba quit working. The error is from Eclipse LogCat.

package com.example.jimyamba;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View.OnClickListener;
import android.view.View;
import android.view.View.OnKeyListener;
import android.widget.Button;
import android.widget.EditText;
import android.util.Log;;

public class MainActivity extends Activity implements OnClickListener{

    Button buttonUpdate;
EditText editStatus;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.status);

    buttonUpdate = (Button)findViewById(R.id.button_update);
    editStatus = (EditText) findViewById(R.id.edit_status);

    buttonUpdate.setOnKeyListener((OnKeyListener) this.buttonUpdate);
}

@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;
}

public void onClick(View v){
    String statusText = editStatus.getText().toString();
    Log.d("StatusActivity","onClicked with text:"  + statusText);
}

}

Upvotes: 0

Views: 1504

Answers (3)

sweggersen
sweggersen

Reputation: 2362

What are you trying to accomplish? You have implemented OnClickListener so if all you need is to execute what's inside of the onClick method with an OnClickListener, just change

buttonUpdate.setOnKeyListener((OnKeyListener) this.buttonUpdate);

With

buttonUpdate.setOnClickListener(this);

Or if you want OnKeyListener do what techiServices suggested

Upvotes: 1

techi.services
techi.services

Reputation: 8533

buttonUpdate.setOnKeyListener((OnKeyListener) this.buttonUpdate);

should be

buttonUpdate.setOnKeyListener(new View.OnKeyListener() {
    @Override
    public boolean onKey(View v, int keyCode, KeyEvent event) {
        // TODO Auto-generated method stub
        return false;
    }
});

Look at http://developer.android.com/reference/android/view/View.OnKeyListener.html

Upvotes: 1

Scott
Scott

Reputation: 1652

The error is in the line buttonUpdate.setOnKeyListener((OnKeyListener) this.buttonUpdate);. Just as the error says, you cannot cast a button to an OnKeyListener. Explicit casting requires a relationship via class hierarchy - Button and OnKeyListener are not related (OnKeyListener is an interface).

If you want to maintain your set up you can create a class that extends Button and Implements OnKeyListener. You will have to edit you xml to have your custom view in place of the button.

Upvotes: 1

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