本文介绍了如何使操作调用一次的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
让我们说我有无限的viewpager每个已着色。
因此,对应用程序的关闭操作再次被调用,但我想的是下一次启动该操作不应该再次调用
Let's say i have unlimited viewpager and each have been colored.So on close of the app the operation again being called but what i want is for next start up that operation should not be called again
推荐答案
根据您的问题,这种讨论和项目链接,就尝试了这一点:
Based on your question, this discussion and the project link, just try this out:
在 MainActivity
添加这两个全局:
/**
* {@link SharedPreferences} key for the random int array.
*/
public static final String KEY_RANDOM_INT_FOR_INDEX = "random_int_index";
/**
* Value holding the total number of images.
*/
public static final int TOTAL_IMAGES = 8;
然后,在的onCreate
的 MainActivity
的末尾再次添加:
// Get a reference to the default SharedPreferences
SharedPreferences defSharedPreference = PreferenceManager
.getDefaultSharedPreferences(this);
// Check if there is a random int for at least 1 index
if (defSharedPreference.getInt(KEY_RANDOM_INT_FOR_INDEX + "_0", -1) == -1) {
// Generate array of <TOTAL_IMAGES> random ints;
ArrayList<Integer> allInts = new ArrayList<Integer>();
for (int i = 0; i < TOTAL_IMAGES; i++) {
allInts.add(i);
}
// Editor instance for modifying SharedPreferences;
SharedPreferences.Editor sp_editor = defSharedPreference.edit();
// Generate random ints;
for (int i = 0; i < TOTAL_IMAGES; i++) {
int range = allInts.size();
int pickIndex = (int) (Math.random() * range);
int value = allInts.remove(pickIndex);
// System.out.print("\nindex: " + i + "\t=\t" + value);
// Save the random value with the key;
sp_editor.putInt(KEY_RANDOM_INT_FOR_INDEX + "_" + i, value);
}
// Save the editors queue in the SharedPreferences;
sp_editor.commit();
}
最后,在 onCreateView
MyFragment
的补充:
// Get a reference to the default SharedPreferences
SharedPreferences defSharedPreference = PreferenceManager
.getDefaultSharedPreferences(getActivity());
// Calculate the index of the page from base of TOTAL_IMAGES;
int pageIndexInTotalImages = (mCurrentPage - 1)
% MainActivity.TOTAL_IMAGES;
// Calculate the index of the random image for the page;
int imageID = defSharedPreference.getInt(
MainActivity.KEY_RANDOM_INT_FOR_INDEX + "_"
+ pageIndexInTotalImages, 0);
int resourceImageID = imageID + R.drawable.image0;
假设你有的ImageView
在 myfragment_layout
设置,您可以使用加载图像:
Assuming you have the ImageView
set up in myfragment_layout
, you can load the image using:
&LT; ImageView的&GT; .setImageResource(resourceImageID);
这篇关于如何使操作调用一次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!