ViewPager标题直到我点击它才会出现

I am learning to use ViewPager and PagerTabStrip to implement navigation bar. I have implemented it, my problem is: every time I open the app fresh, the titles don't show, but after I swipe it once, the titles all appear again, and then everything is normal. code shown below:

我正在学习如何使用ViewPager和PagerTabStrip来实现导航条。我已经实现了，我的问题是:每次打开应用程序时，标题都不显示，但在我刷过一次之后，标题再次出现，然后一切正常。代码如下所示:

Customised Adapter

定制适配器

public class MyPagerAdapter extends PagerAdapter {
    private List<View> viewList;
    private List<String> titleList;

    public MyPagerAdapter(List<View> viewList, List<String> titleList){
        this.viewList = viewList;
        this.titleList = titleList;
    }

    @Override
    public int getCount() {
        return viewList.size();
    }

    @Override
    public boolean isViewFromObject(View view, Object o) {
        return view == o;
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        container.addView(viewList.get(position));
        return viewList.get(position);
    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        container.removeView(viewList.get(position));
    }

    @Override
    public CharSequence getPageTitle(int position) {
        return titleList.get(position);
    }
}

.xml File:

. xml文件:

<android.support.v4.view.ViewPager
    android:id="@+id/viewPager"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center">

    <android.support.v4.view.PagerTabStrip
        android:id="@+id/tab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        />

</android.support.v4.view.ViewPager>

This is the screenshot of "Just clicked the app icon":

这是“刚刚点击app图标”的截图:

And this is after I swiped to the second page:

这是我翻到第二页后

I'm really frustrated. Thanks!!

我真的很沮丧。谢谢! !

4 个解决方案

#1

It is an issue appeared in com.android.support:appcompat-v7:23.0.0. You can refer here https://code.google.com/p/android/issues/detail?id=183127

支持:appcompat-v7:23.0.0。您可以在这里参考https://code.google.com/p/android/issues/detail?id=183127

In that link google support team have mention that defect would be fixed in future releases. So for now solution is build the project using com.android.support:appcompat-v7:22.2.1

在该链接中，谷歌支持团队提到缺陷将在未来的版本中得到修复。目前的解决方案是使用com.android.support:appcompat-v7:22.2.1构建项目

Update : If feasible for you then you can go ahead with another solution provided by @nidheeshdas. I have tried on simple project; it work Modified solution of @nidheeshdas inside onResume() of Activity

更新:如果可行，那么可以使用@nidheeshdas提供的另一个解决方案。我尝试过简单的项目;它可以在活动的onResume()中修改@nidheeshdas的解决方案

viewPager.setCurrentItem(1);
    viewPager.postDelayed(new Runnable() {
        @Override
        public void run() {
            viewPager.setCurrentItem(0);
        }
    },100);

New Update: As mentioned in the above google issue tracker link and comments from JP Ventura. I have tried with new version of library and issue seems to be fixed.

新的更新:如上面提到的谷歌问题跟踪链接和来自JP文图拉的评论。我尝试了新版本的图书馆，问题似乎是固定的。

#2

Instead of using android.support.v4.view.PagerTabStrip , use android.support.design.widget.TabLayout for displaying tabs for viewPager. It is included in Google Design Support Library.

而不是使用android.support.v4.view。PagerTabStrip使用android.support.design.widget.TabLayout来显示viewPager的选项卡。它包含在谷歌设计支持库中。

See this link for more information http://android-developers.blogspot.in/2015/05/android-design-support-library.html

有关更多信息，请参见此链接:http://android- developers.blogspot.in5//201505/android -design-support-library.html

Just few lines:

只是几行:

viewPager=(ViewPager)v.findViewById(R.id.viewPager);

ViewPagerAdapter adapter=new ViewPagerAdapter(this.getChildFragmentManager(),doctor);
adapter.setViewPagerFragmentListener(this);
viewPager.setAdapter(adapter);

tabLayout.setupWithViewPager(viewPager);  //Sync Tabs with viewPager
tabLayout.setTabsFromPagerAdapter(adapter);  //Setup tabs titles 

And to change the titles use the following code in ViewPagerAdapter

要更改标题，请在ViewPagerAdapter中使用以下代码

@Override
public CharSequence getPageTitle(int position) {
    switch (position){
        case 0:
            return "Title 1";
        case 1:
            return "Title 2";
        case 2:
            return "Title 3";
    }
    return super.getPageTitle(position);
}

#3

I also recently started to have this problem, and after a little bit of testing I think I found a bug in Android's latest support package update.

我最近也开始出现这个问题，在进行了一些测试之后，我认为我在Android最新的支持包更新中发现了一个bug。

The problem appears in to be in com.android.support:appcompat-v7:23.0.0.

问题出现在com.android.support:appcompat-v7:23.0.0。

Try changing the dependency back to com.android.support:appcompat-v7:22.2.1 (second latest update) and see if that works.

尝试将依赖项更改回com.android.support:appcompat-v7:22.2.1(第二次更新)，看看是否有效。

Unfortunately, I have yet to find any solution to get it to work with the latest support package update.

不幸的是，我还没有找到任何解决方案来让它与最新的支持包更新一起工作。

#4

Try this. Its seems to be working for me.

试试这个。它似乎对我有用。

@Override
protected void onResume() {
    super.onResume();
    pager.setCurrentItem(1);
    Task.delay(500).continueWith(new Continuation<Void, Object>() {
        @Override
        public Object then(Task<Void> task) throws Exception {
            pager.setCurrentItem(0);
            return null;
        }
    }, Task.UI_THREAD_EXECUTOR);
}

onResume set the pager to 1 and then back to 0. This makes the title appear the page loads the first time.

onResume将寻呼机设置为1，然后返回到0。这使得标题出现在页面第一次加载时。