Android back鍵操作

1.重點程式碼

public boolean onKeyDown(int keyCode, KeyEvent event) {

if (keyCode == KeyEvent.KEYCODE_BACK) {

new AlertDialog.Builder(this, 1)

.setMessage("Are you leaving the application?")

.setNegativeButton("No",

new DialogInterface.OnClickListener() {

@Override

public void onClick(DialogInterface dialog,int which) {}}).setPositiveButton("Yes",new DialogInterface.OnClickListener(){ 

public void onClick(DialogInterface dialog,int whichButton) {

           finish(); 

}}).show(); 

}

return super.onKeyDown(keyCode, event);

}