传递额外设备和屏幕旋转 [英] Passing Extras and screen rotation

问题描述

这样的问题周期性地出现。如果这已经涵盖对不起之前，但我是一个新手，但没有找到合适的答案。它涉及的正确实施课程和活动之间的沟通。

This kind of questions appear periodically. Sorry if this has been covered before, but I'm a newbie and couldn't find the appropriate answer. It deals with the correct implementation of communication between classes and activities.

我做了一个画廊的应用程序。它有3个主要活动：主之一，来搜索使用模式的文件名;一个拇指之一，显示所有在GridView匹配模式为缩略图的图像，以及图片的活动，打开一个全尺寸的图像，当你点击大拇指拇指。我通过传递给图片活动的意图的文件名（阵列），而位置（一个 INT ）在GridView被点击的拇指。

I made a gallery app. It has 3 main activities: the Main one, to search for filenames using a pattern; a Thumb one, that shows all the images that matched the pattern as thumbnails in a gridview, and a Photo activity, that opens a full sized image when you click a thumb in Thumbs. I pass to the Photo activity via an Intent the filenames (an array), and the position (an int) of the clicked thumb in the gridview.

这第三个图片的活动只有一个观点就可以了：一个 TouchImageView ，我改编为$ P $根据在那里你shortclick的图像（左，右或中间）上pvious /下一个开关和变焦。此外，我添加了一个longclick监听器图片来显示EXIF信息。

This third Photo activity has only one view on it: a TouchImageView, that I adapted for previous/next switching and zooming according to where you shortclick on the image (left, right or middle). Moreover, I added a longclick listener to Photo to show EXIF info.

事情是工作，但我不开心的实施......有些东西是不正确的。

The thing is working, but I am not happy with the implementation... Some things are not right.

一个我遇到的问题是，如果我点击图像的右侧，看到未来的图片的活动，它切换正常（位置++ ），但旋转设备原来在位置出现时。

One of the problems I am experiencing is that, if I click on the right of the image to see the next in the Photo activity, it switches fine (position++), but when rotating the device the original one at position appears.

正在发生的事情是，图片旋转图像，当被销毁由于某种原因再次重启，无需服从 super.onCreate（savedInstanceState ），加载再额外（即位置仅在图片改变，而不是在父活动）。

What is happening is that Photo is destroyed when rotating the image, and for some reason it restarts again, without obeying super.onCreate(savedInstanceState), loading again the Extras (the position only changed in Photo, not on the parent activities).

我试着用 startActivityForResult 而不是 startActivity ，但失败了......

I tried with startActivityForResult instead of startActivity, but failed...

当然，我可以做一些做作保存位置数据，但应该有一些概念，我不理解如何活动的工作，我想这样做的权利。

Of course I can do something contrived to save the position data, but there should be something "conceptual" that I am not understanding about how activities work, and I want to do this right.

有人可以解释我什么，我做错了，这是实现我想要的，而最好的方法，为什么？

Can someone please explain me what I am doing wrong, which is the best method to implement what I want, and why?

非常感谢！

推荐答案

试试这个code存储值的活动

Try this code to store the values for the activity

Long value;

protected void onSaveInstanceState(Bundle onOrientChange) {
    super.onSaveInstanceState(onOrientChange);
    onOrientChange.putLong("myValue", value);  
}

和中的onCreate（）恢复值：

And restore the values in onCreate():

public void onCreate(Bundle onOrientChange) {
  if (onOrientChange!= null){
   value = onOrientChange.getLong("myValue");
  }
}

通常你恢复的onCreate您的状态（）。这是可能给它的 onRestoreInstanceState恢复（）为好，但不是很普遍。 （ onRestoreInstanceState（）在 ONSTART被称为（），而的onCreate（）在 ONSTART被称为（）。

Usually you restore your state in onCreate(). It is possible to restore it in onRestoreInstanceState() as well, but not very common. (onRestoreInstanceState() is called after onStart(), whereas onCreate() is called before onStart().

使用看跌期权的方法来存储值的onSaveInstanceState（）

Use the put methods to store values in onSaveInstanceState()

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