使用Intent将数据从.java类发送到Main Activity [英] Sending Data from .java Class to Main Activity using Intents

问题描述

我的应用程序中，我需要将变量(经度)的数据发送到Main Activity，但是尝试打印该值时得到的是空值.这是代码段.

I my app , I need to send the data of a variable (Longitude) to the Main Activity ,but am i getting a null value when trying to print the value .Here is the piece of code.

try
        {
            ExifInterface exif = new ExifInterface(sd.toString()); 

            _longitude=getExifTag(exif,ExifInterface.TAG_GPS_LONGITUDE);

            exif.saveAttributes();

            Intent intent1 = new Intent(getApplicationContext(),MainActivity.class);
            intent1.putExtra("ParkingInfo._longitude", _longitude);

        }catch(IOException e)
        {
            e.printStackTrace();
        }
and here is the method declaration for getApplicationContext()


private Context getApplicationContext() {
    // TODO Auto-generated method stub
    return null;
}

是因为getApplicationContext()返回一个空值就是获取一个空值，如果是的话，我应该用它替换什么以便我可以在MainActivity中获取值

is it because the getApplicationContext() is returning a null value am getting a null value,if so what should i must replace with it so that I can get my values in the MainActivity

推荐答案

如果它是普通的.java类，请创建一个方法

If it is a Plain .java class create a method

public double returnData()
{
      ExifInterface exif = new ExifInterface(sd.toString()); 
      _longitude=getExifTag(exif,ExifInterface.TAG_GPS_LONGITUDE);
      exif.saveAttributes();

    return _longitude;// assuming _longitude is double
}

在MainActivity中

In MainActivity

 MyJavaClassName my = new MyJavaClassName();
 double value = my.returnData();

这篇关于使用Intent将数据从.java类发送到Main Activity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！