android.content.Context.getSharedPreferences(java.lang.String,int)'对一个空对象引用[duplicate](android.content.Context.getSharedPreferences(java.lang.String, int)' on a null object reference [duplicate])
这个问题在这里已经有了答案:
我不明白这个错误:/
我尝试将用户名保存在共享首选项中,但我有空对象,但在我的代码中,我有一些东西:例如,如果管理员连接,保存的用户名是“Administrateur”,但错误告诉我该对象是空的。
这是我的代码:
public class SharedPreferencesUtils { public static final String SHARED_KEY_RESULTS= "TABLEAU"; public SharedPreferencesUtils() { } private static WeakReference<SharedPreferences> sharedPref; private static Context mContext; private static final String PREF_NAME = "MY_PREFRRENCES"; public synchronized static void init(Context context) { if (mContext == null) { mContext = context; sharedPref = new WeakReference<>(context .getSharedPreferences(PREF_NAME, Activity.MODE_PRIVATE)); } } private static SharedPreferences getSharedPref() { if (sharedPref == null || sharedPref.get() == null) { sharedPref = new WeakReference<>(mContext .getSharedPreferences(PREF_NAME, Activity.MODE_PRIVATE)); } return sharedPref.get(); } //region STRING PREF public static void setStringPreference(final String key, final String value) { SharedPreferences.Editor editor = getSharedPref().edit(); editor.putString(key, value); editor.apply(); } public static String getStringPreference(final String key) { return getSharedPref().getString(key, null); } public static String getStringPreference(final String key, String defaultValue) { return getSharedPref().getString(key, defaultValue); } //endregion public static void removePreference(String key) { SharedPreferences.Editor editor = getSharedPref().edit(); editor.remove(key); editor.apply(); } public static void clearAllPreferences() { SharedPreferences.Editor editor = getSharedPref().edit(); editor.clear(); editor.commit(); } }
主要活动
protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_login); name_user = new String[2]; TextView login_titre = (TextView) findViewById(R.id.login_label); username = (EditText) findViewById(R.id.edit_user); password = (EditText) findViewById(R.id.edit_password); Button checking = (Button) findViewById(R.id.button); Police police = new Police(); police.setFont(Login.this, login_titre, "LemonMilklight.otf"); checking.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Retrofit retrofit = new Retrofit.Builder() .baseUrl(CheckLogin.ENDPOINT) .build(); CheckLogin api = retrofit.create(CheckLogin.class); api.Check( username.getText().toString(), password.getText().toString()).enqueue( new Callback<ResponseBody>() { @Override public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) { BufferedReader reader = null; String output = ""; try { reader = new BufferedReader(new InputStreamReader(response.body().byteStream())); output = reader.readLine(); } catch (IOException e) { e.printStackTrace(); } Toast.makeText(Login.this, output, Toast.LENGTH_LONG).show(); name_user = output.split(" "); String save_name = name_user[1]; try { SharedPreferencesUtils.setStringPreference("Utilisateur", save_name); } catch (Exception e) { Log.e("Erreur", e.getMessage()); }
感谢您的帮助。 :)
This question already has an answer here:
I don't understand this mistake :/
I try to save the user name in a Shared Preferences but I have the null object but in my code, I have somethings : for example, if the admin connects, the user name saved is "Administrateur" but the error tells me that the object is empty.
Here is my code :
public class SharedPreferencesUtils { public static final String SHARED_KEY_RESULTS= "TABLEAU"; public SharedPreferencesUtils() { } private static WeakReference<SharedPreferences> sharedPref; private static Context mContext; private static final String PREF_NAME = "MY_PREFRRENCES"; public synchronized static void init(Context context) { if (mContext == null) { mContext = context; sharedPref = new WeakReference<>(context .getSharedPreferences(PREF_NAME, Activity.MODE_PRIVATE)); } } private static SharedPreferences getSharedPref() { if (sharedPref == null || sharedPref.get() == null) { sharedPref = new WeakReference<>(mContext .getSharedPreferences(PREF_NAME, Activity.MODE_PRIVATE)); } return sharedPref.get(); } //region STRING PREF public static void setStringPreference(final String key, final String value) { SharedPreferences.Editor editor = getSharedPref().edit(); editor.putString(key, value); editor.apply(); } public static String getStringPreference(final String key) { return getSharedPref().getString(key, null); } public static String getStringPreference(final String key, String defaultValue) { return getSharedPref().getString(key, defaultValue); } //endregion public static void removePreference(String key) { SharedPreferences.Editor editor = getSharedPref().edit(); editor.remove(key); editor.apply(); } public static void clearAllPreferences() { SharedPreferences.Editor editor = getSharedPref().edit(); editor.clear(); editor.commit(); } }
Main Activity
protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_login); name_user = new String[2]; TextView login_titre = (TextView) findViewById(R.id.login_label); username = (EditText) findViewById(R.id.edit_user); password = (EditText) findViewById(R.id.edit_password); Button checking = (Button) findViewById(R.id.button); Police police = new Police(); police.setFont(Login.this, login_titre, "LemonMilklight.otf"); checking.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Retrofit retrofit = new Retrofit.Builder() .baseUrl(CheckLogin.ENDPOINT) .build(); CheckLogin api = retrofit.create(CheckLogin.class); api.Check( username.getText().toString(), password.getText().toString()).enqueue( new Callback<ResponseBody>() { @Override public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) { BufferedReader reader = null; String output = ""; try { reader = new BufferedReader(new InputStreamReader(response.body().byteStream())); output = reader.readLine(); } catch (IOException e) { e.printStackTrace(); } Toast.makeText(Login.this, output, Toast.LENGTH_LONG).show(); name_user = output.split(" "); String save_name = name_user[1]; try { SharedPreferencesUtils.setStringPreference("Utilisateur", save_name); } catch (Exception e) { Log.e("Erreur", e.getMessage()); }
Thanks for you help. :)
原文:https://stackoverflow.com/questions/49195203
最满意答案
我的解决方案在这里http://codex.wordpress.org/Class_Reference/WP_Query
我做了两个查询,在这种情况下,我没有使用分页,也许这可以提供帮助
$sticky = get_option( 'sticky_posts' ); $args_nonsticky = array( 'showposts' => -1, 'post__not_in' => $sticky ); $args_sticky = array( 'posts_per_page' => -1, 'post__in' => $sticky ); $the_query_sticky = new WP_Query($args_sticky); $the_query_nonsticky = new WP_Query($args_nonsticky); if(!$the_query_sticky->have_posts() && !$the_query_nonsticky->have_posts()){ //echo '<h1>NO POSTS FOUND</h1>'; }else{ if ( $sticky[0] ) { while ($the_query_sticky->have_posts()) : $the_query_sticky->the_post(); //sticky if so... endwhile; } while ($the_query_nonsticky->have_posts()) : $the_query_nonsticky->the_post(); // non sticky endwhile; }
My solution here http://codex.wordpress.org/Class_Reference/WP_Query
I made two queries, in this case I'm not using pagination maybe this can help
$sticky = get_option( 'sticky_posts' ); $args_nonsticky = array( 'showposts' => -1, 'post__not_in' => $sticky ); $args_sticky = array( 'posts_per_page' => -1, 'post__in' => $sticky ); $the_query_sticky = new WP_Query($args_sticky); $the_query_nonsticky = new WP_Query($args_nonsticky); if(!$the_query_sticky->have_posts() && !$the_query_nonsticky->have_posts()){ //echo '<h1>NO POSTS FOUND</h1>'; }else{ if ( $sticky[0] ) { while ($the_query_sticky->have_posts()) : $the_query_sticky->the_post(); //sticky if so... endwhile; } while ($the_query_nonsticky->have_posts()) : $the_query_nonsticky->the_post(); // non sticky endwhile; }
相关问答
更多-
如何检查当前帖子是否是Wordpress中的第一篇或最后一篇文章(How to Check if Current Post is the First or Last Post in Wordpress)[2024-02-27]
如果您只想检查它们的存在而不需要链接,则应使用get_previous_post和get_next_post 。 如果您只是在if测试中使用它们,它们不会应用您将忽略的不必要的格式。 您仍然可以通过将其传递给get_permalink来从它返回的post对象获取链接。 If you just want to check for their existence and don't need the link, you should use get_previous_post and get_next_post ... -
我的解决方案在这里http://codex.wordpress.org/Class_Reference/WP_Query 我做了两个查询,在这种情况下,我没有使用分页,也许这可以提供帮助 $sticky = get_option( 'sticky_posts' ); $args_nonsticky = array( 'showposts' => -1, 'post__not_in' => $sticky ); $args_sticky ...
-
也许这可以帮助: $first = false; if( $my_query->current_post == 0 && !is_paged() ) { $first = true; } 然后你和你一起做这个:未测试语法错误。 所以试试这个: 3, 'post__n ...经过几天的尝试和失败,我能够构建以下解决方案: 将以下代码添加到位于wp-content / themes / nameOfTheme中的 header.php文件中。 确保在开幕前没有空位或进入 query('showposts=1'); while ($recentPosts->have_posts()) : $recentPosts->the_p ...
WordPress循环忽略三个单独的meta_values的第一篇文章(WordPress loop ignore first post of three separate meta_values)[2022-09-07]
以下是我终于无法完成上述任务的方式WordPress第一篇近期帖子(WordPress First Recent Post)[2024-01-20]
http://goo.gl/d0AbHn 您可以修改css以使用first-child选择器: [POST-CLASS]:first-child { font-size: 30px; [...] } 或者,安装'display posts shortcode'插件并使用schortcode [display-posts posts_per_page =“1”] http://goo.gl/d0AbHn You could modify the css to use the first-ch ...wp trim words功能仅适用于第一篇文章(wordpress)(wp trim words function only for first post (wordpress))[2022-04-02]
创建一个变量,如果它是第一个帖子将返回true ,否则返回false :我已经在循环本身看到了这种事情 - 评论澄清你是否想在网站范围内这样做,或者特别想要挂钩到post_class(然后再次,你可以编辑loop.php或内容-LOOPTYPE .php并反复使用它。 这是一个示例循环:...我认为这是因为你的代码总是在偏移量上加1。 在你的JavaScript中,不应该这样: offset: (page * ppp) + 1, 是 offset: (page * ppp), I think it is because your code is always adding 1 to the offset. In your javascript, shouldn't this: offset: (page * ppp) + 1, be offset: (page * ppp),你可以使用一个基本的if结构。 在循环开始之前设置变量 $someVariable = 0; 然后在循环中显示帖子后: if ($someVariable == 0) { print "whatever" $someVariable++; } you can use a basic if constuct. Before a loop starts set variable $someVariable = 0; then in the loop, after the post ...相关文章
更多- Object Oriented Programming
- Guava处理java int实用工具类-Ints类
- Guava学习笔记:复写的Object常用方法
- Becoming a data scientist
- Solr: a custom Search RequestHandler
- mybatis There is no getter for property named 'xx' in 'class java.lang.String
- Spring Data: a new perspective of data operations
- Drupal Forums instead of phpBB or vBulletin: A casestudy
- Guava Optional类详解-处理null值
- Cannot expose request attribute 'website' because of an existing model object of the same name 的解决方案
最新问答
更多- 您如何使用git diff文件,并将其应用于同一存储库的副本的本地分支?(How do you take a git diff file, and apply it to a local branch that is a copy of the same repository?)
- 将长浮点值剪切为2个小数点并复制到字符数组(Cut Long Float Value to 2 decimal points and copy to Character Array)
- OctoberCMS侧边栏不呈现(OctoberCMS Sidebar not rendering)
- 页面加载后对象是否有资格进行垃圾回收?(Are objects eligible for garbage collection after the page loads?)
- codeigniter中的语言不能按预期工作(language in codeigniter doesn' t work as expected)
- 在计算机拍照在哪里进入
- 使用cin.get()从c ++中的输入流中丢弃不需要的字符(Using cin.get() to discard unwanted characters from the input stream in c++)
- No for循环将在for循环中运行。(No for loop will run inside for loop. Testing for primes)
- 单页应用程序:页面重新加载(Single Page Application: page reload)
- 在循环中选择具有相似模式的列名称(Selecting Column Name With Similar Pattern in a Loop)
- System.StackOverflow错误(System.StackOverflow error)
- KnockoutJS未在嵌套模板上应用beforeRemove和afterAdd(KnockoutJS not applying beforeRemove and afterAdd on nested templates)
- 散列包括方法和/或嵌套属性(Hash include methods and/or nested attributes)
- android - 如何避免使用Samsung RFS文件系统延迟/冻结?(android - how to avoid lag/freezes with Samsung RFS filesystem?)
- TensorFlow:基于索引列表创建新张量(TensorFlow: Create a new tensor based on list of indices)
- 企业安全培训的各项内容
- 错误:RPC失败;(error: RPC failed; curl transfer closed with outstanding read data remaining)
- C#类名中允许哪些字符?(What characters are allowed in C# class name?)
- NumPy:将int64值存储在np.array中并使用dtype float64并将其转换回整数是否安全?(NumPy: Is it safe to store an int64 value in an np.array with dtype float64 and later convert it back to integer?)
- 注销后如何隐藏导航portlet?(How to hide navigation portlet after logout?)
- 将多个行和可变行移动到列(moving multiple and variable rows to columns)
- 提交表单时忽略基础href,而不使用Javascript(ignore base href when submitting form, without using Javascript)
- 对setOnInfoWindowClickListener的意图(Intent on setOnInfoWindowClickListener)
- Angular $资源不会改变方法(Angular $resource doesn't change method)
- 在Angular 5中不是一个函数(is not a function in Angular 5)
- 如何配置Composite C1以将.m和桌面作为同一站点提供服务(How to configure Composite C1 to serve .m and desktop as the same site)
- 不适用:悬停在悬停时:在元素之前[复制](Don't apply :hover when hovering on :before element [duplicate])
- 常见的python rpc和cli接口(Common python rpc and cli interface)
- Mysql DB单个字段匹配多个其他字段(Mysql DB single field matching to multiple other fields)
- 产品页面上的Magento Up出售对齐问题(Magento Up sell alignment issue on the products page)