[英]Misbehavior with sharedpreferences
在您判斷我之前,我想說一下我讀過這些:
但是我仍然不明白,無法使事情正常進行。 我完全不喜歡自己的喜好。 我的代碼:
public static SharedPreferences sharedAppPreferences;
public static final String AppsListKey = "AppListKey";
public static final String AppsPreferences = "AppsPreferences";
public static ArrayList<String> packageNames;
public void chooseApps(View view) {
sharedAppPreferences = getSharedPreferences(AppsPreferences, Context.MODE_PRIVATE);
if (sharedAppPreferences.contains(AppsListKey)) {
Set<String> buffer = new LinkedHashSet<String>(sharedAppPreferences.getStringSet(AppsListKey, new LinkedHashSet<String>()));
packageNames = new ArrayList<String>(buffer);
} else {
packageNames = new ArrayList<String>();
}
PackageManager packageManager = getPackageManager();
int flags = PackageManager.GET_META_DATA | PackageManager.GET_SHARED_LIBRARY_FILES | PackageManager.GET_UNINSTALLED_PACKAGES;
List<ApplicationInfo> packageList = packageManager.getInstalledApplications(flags);
for (ApplicationInfo pack : packageList) {
if (((pack.flags & ApplicationInfo.FLAG_SYSTEM) == 1) || packageNames.contains(pack.loadLabel(packageManager).toString())) {
// System application or already in array
} else {
// Installed by user and isnt in array
packageNames.add(pack.loadLabel(packageManager).toString());
}
}
Editor editor = sharedAppPreferences.edit();
Set<String> buffer1 = new LinkedHashSet<String> (packageNames);
editor.putStringSet(AppsListKey, buffer1);
editor.commit();
//packageNames.clear();
//buffer1.clear();
buffer1 = new LinkedHashSet<String>(sharedAppPreferences.getStringSet(AppsListKey, new LinkedHashSet<String>()));
packageNames = new ArrayList<String>(buffer1);
AppList appList = new AppList();
appList.show(getSupportFragmentManager(), "AppList");
}
為什么第一次運行我的應用程序時會顯示如下列表
[Skype, Facebook, Whatsapp, Twitter, Google+]
只要應用程序正在運行就可以...但是如果我殺死我的應用程序並重新啟動,我會得到完全不同的列表,例如
[Whatsapp, Google+, Skype, Twitter, Facebook]
有人可以向我解釋一下這是怎么回事嗎?
列表前后的唯一區別是訂購...
為了擴展我一直在談論的內容,我剛剛意識到您的錯誤。
LinkedHashSet
是有序的。 但是,您存儲在
Set<String> buffer
Set<String>
不排序...
因此,它再次變得混亂。
您需要將其存儲在LinkedHashSet
參數中,如下所示
LinkedHashSet<String> buffer = new LinkedHashSet<String>(sharedAppPreferences.getStringSet(AppsListKey, new LinkedHashSet<String>()));
(我有兩種情況需要對此進行更改。)
編輯:
您可以做的最后一件事是,而不是創建新列表,而是從共享首選項中投射現有列表...
LinkedHashSet<String> buffer = (LinkedHashSet<String>)sharedAppPreferences.getStringSet(AppsListKey, new LinkedHashSet<String>());
還有其他選擇HashSets 這里
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