Question

I have a TextView with the id android:id="@+id/yazi", and I have a button that has build in android:OnClick="gonderB"

and I can complie this code:

package com.seri.bir;

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

public class MainActivity extends Activity {
     Bilmez b;
     TextView t;
    /** Called when the activity is first created. */

    @Override
    public void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        b = new Bilmez();
        t = (TextView) findViewById(R.id.yazi);
    }
    public void gonderB (View v,TextView t,Bilmez b){
        String s = " ..."+this;
        b.yaziYaz(v,s,t);
    }    
}

class Bilmez {
    public void yaziYaz(View v,String s,TextView t){
        t.setText(s);
    }
}

However I have an error.
Can I setText in another class?

Answer 1

You can overwrite onClick of the activity. Avoid the using of the android:OnClick=”gonderB” line in the xml file. I think it is better to implement the onClickListener and attach it to View Objects within your code.

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

public class MainActivity extends Activity implements OnClickListener {
Bilmez b;
TextView t;
Button bt;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    b = new Bilmez();
    t = (TextView) findViewById(R.id.yazi);
    Button bt = (Button) findViewById(R.id.btn);
    bt.setOnClickListener(this);
}

@Override
public void onClick(View clickedView) {
    switch (clickedView.getId()) {
    case R.id.btn:
        String s = "...." + this;
        b.changeText(t,s);
        break;
    }}  //end of main class    }

In the changeText method you change the text of the TextView. This method can if be placed in another class if you like that.

class Bilmez {
            public void changeText(TextView t, String s){
                    t.setText(s);
            }
}