首页 \ 问答 \ 无论我们将tab2设置为默认选项卡，android始终都会调用android第一个tab意图oncreate(android first tab intent oncreate always called regardless we set tab2 as default tab)

无论我们将tab2设置为默认选项卡，android始终都会调用android第一个tab意图oncreate(android first tab intent oncreate always called regardless we set tab2 as default tab)

 以下是具有意向数据的选项卡示例。  
 在调试过程中，我发现总是在第一个选项卡时，我们在标签主机中添加下面的选项卡  
tabHost.addTab(tabHost.newTabSpec("tab1")
                    .setIndicator("list")
                    .setContent(new Intent(this, List1.class)));
 
 oncreate方法的“List1”意图被调用，无论它是我们的当前标签或不，即使如果我将tab2定义为当前标签如何解决此问题？  
public class Tabs3 extends TabActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        final TabHost tabHost = getTabHost();

        tabHost.addTab(tabHost.newTabSpec("tab1")
                .setIndicator("list")
                .setContent(new Intent(this, List1.class)));

        tabHost.addTab(tabHost.newTabSpec("tab2")
                .setIndicator("photo list")
                .setContent(new Intent(this, List8.class).addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)));

        // This tab sets the intent flag so that it is recreated each time
        // the tab is clicked.
        tabHost.addTab(tabHost.newTabSpec("tab3")
                .setIndicator("destroy")
                .setContent(new Intent(this, Controls2.class)
                        .addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)));
    }
}

Following is the example of tabs with intent data. 
While debugging i found that always when first tab we add in tab host in our case following tab 
tabHost.addTab(tabHost.newTabSpec("tab1")
                    .setIndicator("list")
                    .setContent(new Intent(this, List1.class)));
 
oncreate method of "List1" intent get called regardless it is our current tab or not even if if i define tab2 as a current tab how to fix this ? 
public class Tabs3 extends TabActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        final TabHost tabHost = getTabHost();

        tabHost.addTab(tabHost.newTabSpec("tab1")
                .setIndicator("list")
                .setContent(new Intent(this, List1.class)));

        tabHost.addTab(tabHost.newTabSpec("tab2")
                .setIndicator("photo list")
                .setContent(new Intent(this, List8.class).addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)));

        // This tab sets the intent flag so that it is recreated each time
        // the tab is clicked.
        tabHost.addTab(tabHost.newTabSpec("tab3")
                .setIndicator("destroy")
                .setContent(new Intent(this, Controls2.class)
                        .addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)));
    }
}

原文：https://stackoverflow.com/questions/2370630

更新时间：2022-06-06 13:06

最满意答案

 您应该使用group by expression name 。  
select 
--   locate( '.', ip, locate( '.', ip, locate( '.', ip ) + 1 ) + 1 ) as l,
   substr( ip, 1, locate( '.', ip
                          , locate( '.', ip
                                    , locate( '.', ip ) + 1 ) + 1 ) - 1 ) as subip,
   count(ip) as count
from ip_list
group by ( subip )
order by count desc
;
 
 编辑1 ： 
 不需要使用locate 。 SUBSTR_INDEX可用于过滤IP的子集。  
 示例 ：  
select
       substring_index( ip, '.', 3 ) as subip
     , count(ip) as count
  from ip_list
 group by ( subip )
 order by count desc
 
 请参阅文档 ：  
 
  MySQL：SUBSTR（str，pos，len） 
   
    从字符串str返回一个子串len个字符，从位置pos开始。  
   
  MySQL：SUBSTRING_INDEX（str，delim，count） 
   
    在分隔符delim的计数出现之前，从字符串str返回子字符串。  
   

You should have used group by expression name.  
select 
--   locate( '.', ip, locate( '.', ip, locate( '.', ip ) + 1 ) + 1 ) as l,
   substr( ip, 1, locate( '.', ip
                          , locate( '.', ip
                                    , locate( '.', ip ) + 1 ) + 1 ) - 1 ) as subip,
   count(ip) as count
from ip_list
group by ( subip )
order by count desc
;
 
EDIT 1:
 Use of locate is not required. SUBSTR_INDEX can be used to filter the subset of IP's. 
Example:  
select
       substring_index( ip, '.', 3 ) as subip
     , count(ip) as count
  from ip_list
 group by ( subip )
 order by count desc
 
Refer to Documentation:  
 
 MySQL: SUBSTR(str,pos,len) 
   
   Return a substring len characters long from string str, starting at position pos. 
   
 MySQL: SUBSTRING_INDEX(str,delim,count) 
   
   Returns the substring from string str before count occurrences of the delimiter delim.

无论我们将tab2设置为默认选项卡，android始终都会调用android第一个tab意图oncreate(android first tab intent oncreate always called regardless we set tab2 as default tab)

最满意答案

相关问答

如何获得使用Java在同一网络（子网）中连接的IP列表(How to get a list of IP connected in same network (subnet) using Java)[2022-05-29]

有什么数据库专业书籍介绍？[2022-05-19]

Python - ip < - >子网匹配？(Python - ip <-> subnet match? [duplicate])[2023-01-27]

标准/安全的方法来检查IP地址是否在范围/子网中(Standard/safe way to check if IP address is in range/subnet)[2023-06-27]

AWS：子网中分配的IP列表(AWS: List of assigned IPs in subnet)[2023-12-12]

比较两个ip子网(Compare two ip subnet)[2024-03-19]

需要打破IP子网(Need to break down a IP subnet)[2023-01-10]

如何在MySQL中按子网分组IP列表？(How to group IP list by subnet in MySQL?)[2023-09-02]

用于查找列表中的IP是否属于不同子网的Pythonic方法(Pythonic way to find if an IP in a list belongs to a different subnet)[2021-10-16]

（bash）检查子网范围文件中的IP((bash) check if IP in subnet range file)[2022-04-08]

相关文章

最新问答