通过创建实例android将MainActivity类中的方法调用到另一个类

I'm looking for a good example, how I can call a method that is declared in MainAcitivity from another class in the same package.

我正在寻找一个很好的例子，我如何调用同一个包中另一个类在MainAcitivity中声明的方法。

I have a getSMS method in MainAcitivity class, that looks like as following:

我在MainAcitivity类中有一个getSMS方法，如下所示：

    private void sendSMS(String phoneNumber, String message) {
            SmsManager sms = SmsManager.getDefault();
            sms.sendTextMessage(phoneNumber, null, message, null, null);
        }
public void getSMS(){
            sendSMS("5556", "You're at home.");
    }

I'm calling getSMS() method in another class from MainActivity class.

我在MainActivity类的另一个类中调用getSMS（）方法。

public void tSMS(){
    MainActivity mainActivity = new MainActivity();
    mainActivity.getSMS();
}

Now I'm calling the method in other class using the conditional statement.

现在我使用条件语句在其他类中调用该方法。

            if (activity.getType() == 3) {
            tSMS();
                }

Logcat:

logcat的：

java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources android.content.Context.getResources()' on a null object reference

1 个解决方案

#1

getSms() and sendSms() shouldn't be defined in your activity. Check some info about structuring your code: https://medium.com/@dmilicic/a-detailed-guide-on-developing-android-apps-using-the-clean-architecture-pattern-d38d71e94029

不应在您的活动中定义getSms（）和sendSms（）。查看有关构建代码的一些信息：https：//medium.com/@dmilicic/a-detailed-guide-on-developing-android-apps-using-the-clean-architecture-pattern-d38d71e94029