Question

How do i customize alert dialog like GTasks

Answer 1

You can create a custom dialog box and make it as you want.
Yes you can change your Dialog box as you want.You can do this by creating a custom dialog box.
Step1.Create a style in String file in res

<style name="myQuitDialog" parent="android:Theme.Dialog"> 
   <item name="android:gravity">center_horizontal</item>

    </style>  

Step2. Create the xml file in layouts

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/layout_quit"
              android:orientation="horizontal"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:background="@drawable/image which u want to show"
 >

Step3. Write code of custom dialog box in src

    class Custom_Dialog extends Dialog {

        protected Custom_Dialog(Context context, int theme) {
            super(context, theme);
            // TODO Auto-generated constructor stub
        }

    }
private void show_alert() {
        final Custom_Dialog alertbox = new Custom_Dialog(this, R.style.myQuitDialog);
        Window window = alertbox.getWindow();
        window.setBackgroundDrawableResource(android.R.color.transparent);
        window.requestFeature(window.FEATURE_NO_TITLE);

        alertbox.show(); 
        alertbox.setCancelable(true);
        alertbox.setCanceledOnTouchOutside(true);


                 alertbox.dismiss();
            }



    }

This is all what you need and accept it if you feel it satisfied you.