1、直接撥打電話

Intent intentPhone = new Intent(Intent.ACTION_CALL, Uri.parse("tel:" + phoneNumber));  
startActivity(intentPhone);
<uses-permission android:name="android.permission.CALL_PHONE" /> 需權限

2、跳轉到撥號面板

Intent intent = newIntent(Intent.ACTION_DIAL,Uri.parse("tel:" + phoneNumber));  
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);  
startActivity(intent);