MainActivity.java
Declare:
AlertDialog.Builder bdr ; //利用AlertDialog.Builder物件建立歡迎訊息的交談窗
init():
new AlertDialog.Builder(this)
.setMessage("交談窗示範教學!\n"+"請按返回鍵關閉交談窗")
.setTitle("歡迎")
.setIcon(android.R.drawable.presence_away)
.setCancelable(true)
.show() ;