Question

Below is my program and I am getting this error:

Description Resource    Path    Location    Type
The method setOnClickListener(View.OnClickListener) in the type View is not applicable for the arguments (welcome)  welcome.java    /testcalculator/src/com/testcalculator  line 31 Java Problem

welcome.java

package com.testcalculator;
public class welcome extends Activity{
   public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
        setContentView(R.layout.welcome1);
        Button playBtn = (Button) findViewById(R.id.playBtn);
        playBtn.setOnItemClickListener();
        Button exitBtn = (Button) findViewById(R.id.exitBtn);
        exitBtn.setOnClickListener(this);
    }
    public void onClick(View v) {
        Intent i;
        switch (v.getId()){
        case R.id.playBtn :
            i = new Intent(this, testcalculator.class);
            startActivity(i);
            break;
        case R.id.exitBtn :
            finish();
            break;
        }
    }
   }

The problem is, I have all the required import options in my problem but still I am getting error message.

Answer 1

You are passing your Activity class as the OnClickListener in this line:

exitBtn.setOnClickListener(this);

However, your class needs to explicitly declare that it is implementing the View.OnCLickListener interface. Change your class declaration line to this:

public class welcome extends Activity implements OnClickListener

---

A couple of other things to note:

You wrote playBtn.setOnItemClickListener(). Perhaps you meant playBtn.setOnClickListener(this)? Buttons don’t have OnItemClickListeners

You can also set an OnClickListener without having the activity class itself implement the interface by declaring an anonymous class. Like this:

playBtn.setOnClickListener(new OnClickListener() {
    public void onClick(View v) {
        // playBtn code
    }
});

exitBtn.setOnClickListener(new OnClickListener() {
    public void onClick(View v) {
        // exitBtn code
    }
});

This way is used more often because it is more readable. By segregating the button onClick code, you can easily tell which button does what, as opposed to putting it all into one method and having the class itself implement OnClickListener.