java.lang.NullPointerException:尝试调用虚拟方法'android.app.ActivityThread $ ApplicationThread [英] java.lang.NullPointerException: Attempt to invoke virtual method 'android.app.ActivityThread$ApplicationThread

问题描述

我知道这可能是重复的，但是我的情况有所不同，需要对此特定问题进行一些解释.

I know this may be a duplicate but my situation is different which requires some explanation on this specific issue.

我遇到了错误:

java.lang.NullPointerException: Attempt to invoke virtual method 'android.app.ActivityThread$ApplicationThread android.app.ActivityThread.getApplicationThread()' on a null object reference

在onClick中，从类MyCalendar

button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            MyCalendar myCalendar = new MyCalendar();
            myCalendar.addEvent();
          //  myCalendar.AddEvent(2,context);
       }
    });

它调用以下方法

public void addEvent(){
    Calendar beginTime = Calendar.getInstance();
    beginTime.set(2018, 11, 14, 7, 30);
    Calendar endTime = Calendar.getInstance();
    endTime.set(2018, 11, 14, 8, 30);
        Intent intent = new Intent(Intent.ACTION_INSERT)
            .setData(Events.CONTENT_URI)
            .putExtra(CalendarContract.EXTRA_EVENT_BEGIN_TIME, beginTime.getTimeInMillis())
            .putExtra(CalendarContract.EXTRA_EVENT_END_TIME, endTime.getTimeInMillis())
            .putExtra(Events.TITLE, "TEST ANDROID")
            .putExtra(Events.DESCRIPTION, "EVENT HAS BEEN ADDED FROM ANDROID STUDIO")
            .putExtra(Events.EVENT_LOCATION, "GIBRALTAR")
            .putExtra(Events.AVAILABILITY, Events.AVAILABILITY_BUSY)
            .putExtra(Events.CALENDAR_ID, 2)
            .putExtra(Intent.EXTRA_EMAIL, "[e-mail]");
    startActivity(intent);
}

当在MainActivity中声明该方法时，它确实起作用，但是现在我将其移至另一个类，它显示了上述异常.

This method does work when it is declared within the MainActivity but now that I have moved it to another class, it is showing that above exception.

我该如何解决?

推荐答案

您将需要将调用活动作为上下文参数传递给您的new MyCalendar(context)调用.然后从您的日历类中调用context.startActivity(intent)

You will need to pass the calling activity as a context parameter to your new MyCalendar(context) call. Then from your calendar class, invoke context.startActivity(intent)

这篇关于java.lang.NullPointerException:尝试调用虚拟方法'android.app.ActivityThread $ ApplicationThread的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！