PaymentEngine对象始终为null

Question

我正在尝试在BlackBerry jde 5.0.0.14版本上构建付款申请。当我调试代码时，PaymentEngine对象始终为null。为什么会这样？我的代码有问题吗？

private PaymentEngine engine = PaymentEngine.getInstance();

public PurchaseDemoScreen()
{
   setTitle("Payment Service SDK Demo");

   if (engine != null) 
    {
       engine.setConnectionMode(PaymentEngine.CONNECTION_MODE_LOCAL);
       //do shopping
    }
   else
    {
         //in-app purchase unavilable
    }
}

Answer 1

您安装了哪个版本的BlackBerry App World？

PaymentEngine.getInstance() 

如果BlackBerry设备未安装BlackBerry App World 2.1或更高版本，则

会返回null。