Changing the style or theme of default alertDialog in Android.

Hello everyone,
Here is a simple example showing how to change the theme of default AlertDialog in android.

To start first create a fresh project named AlertTest.
In the AlertTestDemo.java file copy this code

package com.coderzheaven.pack;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.os.Bundle;

public class AlertTestDemo extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        AlertDialog dialog = new CustomDialog(this);
        dialog.setButton("OK", new OnClickListener()
        {
            public void onClick(DialogInterface arg0, int arg1)
            {
            }
        });
        dialog.setTitle("Coderzheaven");
        dialog.setMessage("Heaven of all working codes!! n Keep Visiting..n" +
        		"Thankyou.");
        dialog.show();
    }
}

Now create a file named “styles.xml” inside the res/values folder and copy this code into it.

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <style name="CenterTextView" parent="@android:style/Widget.TextView">
        <item name="android:gravity">center|center_vertical</item>
    </style>

    <style name="CenterJustifyDialogTitle" parent="@android:style/DialogWindowTitle" >
         <item name="android:gravity">center|center_vertical</item>
         <item name="android:textColor">#000000</item>
    </style>

	<style name="CenterJustifyTheme1" parent="@android:style/Theme.Translucent">
        <item name="android:textViewStyle">@style/CenterTextView</item>
        <item name="android:windowTitleStyle">@style/CenterJustifyDialogTitle</item>
    </style>

    <style name="CenterJustifyTheme2" parent="@android:style/Theme.Black">
        <item name="android:textViewStyle">@style/CenterTextView</item>
        <item name="android:windowTitleStyle">@style/CenterJustifyDialogTitle</item>
    </style>

    <style name="CenterJustifyTheme3" parent="@android:style/Theme.Light">
        <item name="android:textViewStyle">@style/CenterTextView</item>
        <item name="android:windowTitleStyle">@style/CenterJustifyDialogTitle</item>
    </style>

</resources>

Now create another java file named “CustomDialog.java” and copy this code into it.
We will apply the theme through this java file.
The theme is located and named in the above xml file.

package com.coderzheaven.pack;
import android.app.AlertDialog;
import android.content.Context;
import com.coderzheaven.pack.R;


public class CustomDialog extends AlertDialog {
		public CustomDialog(Context ctx)
		{
			super(ctx, R.style.CenterJustifyTheme1);
		}
}