Alert Dialog in Android

This Custom dialog used for Display information or alert to user.

public void dialog_message(String msg)

       {

        final AlertDialog alertDialog = new  AlertDialog.Builder(context.this).create();

              alertDialog.setTitle("Title");

              alertDialog.setIcon(R.drawable.close);

              alertDialog.setMessage(msg);

              alertDialog.setButton("Yes", new DialogInterface.OnClickListener()

              {

                     public void onClick(DialogInterface dialog, int which)

                     {

                           System.exit(0);    

                     }

              });

              alertDialog.setButton2("No", new DialogInterface.OnClickListener()

              {

                     public void onClick(DialogInterface dialog, int which)

                     {    

                           alertDialog.dismiss();

                     }

              });

              alertDialog.show();

       }

2. Single dialog with multiple usage: 
   - This dialog is not used while you are using Date and Time dialog because it has same method (onCreateDialog). As a result below 3rd option is feasible for custom dialog.
     -Dialog id:
                                     final static int DIALOG_Measurement=100;

                     final static int DIALOG_NumberFormate=101;

     -Call dialog like on Button Tap Event:

                     removeDialog(DIALOG_Measurement);

                     showDialog(DIALOG_Measurement);

                     removeDialog(DIALOG_NumberFormate);

                     showDialog(DIALOG_NumberFormate);

Method:

protected Dialog onCreateDialog(int id) {

              AlertDialog dialog = null;

              AlertDialog.Builder builder = null;

              switch(id)

              {

              case DIALOG_Measurement:

                     final CharSequence[] items = {"Imperial","Metric"};

                     builder = new AlertDialog.Builder(this);

                     builder.setTitle("Select Options");

                     builder.setItems(items, new DialogInterface.OnClickListener()

                     {

                           public void onClick(DialogInterface dialog, int item) {

                                  String name=items[item].toString();

                                  TextView txt=(TextView) findViewById(R.id.txt_meas_name);

                                  txt.setText(name);               

                           }                   

                     });

                     builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener()

                     {

                           public void onClick(DialogInterface dialog, int id) {

                                  dialog.cancel();

                           }

                     });

                     dialog = builder.create();

                     break;

              case DIALOG_NumberFormate:

                     final CharSequence[] items1 = {"1000","1,000","1000.00"};

                     builder = new AlertDialog.Builder(this);

                     builder.setTitle("Select Options");

                     builder.setItems(items1, new DialogInterface.OnClickListener()

                     {

                           public void onClick(DialogInterface dialog, int item) {

                                  String name=items1[item].toString();

                                  TextView txt=(TextView) findViewById(R.id.txt_NumFormate_Value);

                                  txt.setText(name);               

                           }

                     });          

                     builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener()

                     {

                           public void onClick(DialogInterface dialog, int id) {

                                  dialog.cancel();

                           }

                     });

                     dialog = builder.create();

                     break;

              }

              return dialog;

       }

2. Custom dialog for user selection:

       private static final int PAIDWITH_CODE=101                     

       String[] temp = null;

       String Paidwith[]={"Visa","MC"};

       temp=Paidwith;  

       showSimplePopUp(PAIDWITH_CODE,"Select Paid with");

 Method:

       private void showSimplePopUp(final int id,String title)

       {

              CharSequence[] itemsPhoto = temp;

              AlertDialog.Builder helpBuilder = new AlertDialog.Builder(this);

              helpBuilder.setTitle(title);

              //helpBuilder.setMessage("This is a Simple Pop Up");

              helpBuilder.setItems(itemsPhoto, new DialogInterface.OnClickListener()

              {

                     public void onClick(DialogInterface dialog, int item)

                     {

                           if (id == PAIDWITH_CODE)

                           {  

                                  String paidwith=temp[item].toString();

                                  txt_paidwith.setText(paidwith);

                           }   

                     }

              });

              // Remember, create doesn't show the dialog

              AlertDialog helpDialog = helpBuilder.create();

              helpDialog.show();

       }