我应该如何选择一个标签在TabLayout编程?
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
我应该如何选择一个标签在TabLayout编程?
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
当前回答
我使用TabLayout切换片段。它在大多数情况下都是有效的,除了当我试图以编程方式使用tab.select(),我的TabLayout选择一个选项卡时。OnTabSelectedListener将触发onTabSelected(TabLayout。Tab Tab),这会让我很伤心。我正在寻找一种不触发侦听器的方法来做程序化选择。
So I adapted @kenodoggy 's answer to my use. I was further facing a problem where some of the internal objects would return null (because they weren't created yet, because I was answering onActivityResult() from my fragment, which occurs before onCreate() in the case the activity is singleTask or singleInstance) so I wrote up a detailed if/else sequence which would report the error and fall through without the NullPointerException that would otherwise trigger. I use Timber for logging, if you're not using that substitute with Log.e().
void updateSelectedTabTo(int position) {
if (tabLayout != null){
int selected = tabLayout.getSelectedTabPosition();
if (selected != -1){
TabLayout.Tab oldTab = tabLayout.getTabAt(0);
if (oldTab != null){
View view = oldTab.getCustomView();
if (view != null){
view.setSelected(false);
}
else {
Timber.e("oldTab customView is null");
}
}
else {
Timber.e("oldTab is null");
}
}
else {
Timber.e("selected is -1");
}
TabLayout.Tab newTab = tabLayout.getTabAt(position);
if (newTab != null){
View view = newTab.getCustomView();
if (view != null){
view.setSelected(false);
}
else {
Timber.e("newTab customView is null");
}
}
else {
Timber.e("newTab is null");
}
}
else {
Timber.e("tablayout is null");
}
}
这里,tabLayout是绑定到XML中的tabLayout对象的内存变量。我不使用滚动标签功能,所以我把它也删除了。
其他回答
用这个:
tabs.getTabAt(index).select();
请记住,如果currentTabIndex和index是相同的,那么这将发送您的流到onTabReselected而不是onTabSelected。
如果你知道你想要选择的标签的索引,你可以这样做:
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
TabLayout.Tab tab = tabLayout.getTabAt(someIndex);
tab.select();
即使你使用TabLayout本身而没有ViewPager(这是非典型的,可能是不好的做法,但我见过这样做),这种技术也是有效的。
这可能不是最终的解决方案,它需要你使用TabLayout和一个ViewPager,但这是我解决它的方法:
void selectPage(int pageIndex)
{
viewPager.setCurrentItem(pageIndex);
tabLayout.setupWithViewPager(viewPager);
}
我测试了使用这段代码对性能的影响有多大,首先在Android Studio中运行该方法时查看CPU和内存监视器,然后将其与我自己在页面之间导航时(使用滑动手势)对CPU和内存的负载进行比较,结果发现差异并不大,所以至少这不是一个可怕的解决方案……
希望这能帮助到一些人!
我是这样解决的:
void selectPage(int pageIndex){
tabLayout.setScrollPosition(pageIndex,0f,true);
viewPager.setCurrentItem(pageIndex);
}
您可以使用以下函数设置TabLayout位置
public void setTab(){
tabLayout.setScrollPosition(YOUR_SCROLL_INDEX,0,true);
tabLayout.setSelected(true);
}