ViewPager addOnPageChangeListener 不能在同一个选项卡上工作单击
ViewPager addOnPageChangeListener not working on same tabClick
我有一个 ViewPager
和 addOnPageChangeListener
。 ViewPager
有 3 个标签视图(tab1、tab2、tab3)。当用户单击 tab2 时,它会加载一些数据(基本上是 RecyclerView
)。此时,如果用户再次点击tab2,我需要重新加载数据,但在这种情况下addOnPageChangeListener
不会被触发。
我的代码:
customPagerAdapter = new CustomPagerAdapter(getSupportFragmentManager(), MainActivity.this);
viewPager.setAdapter(customPagerAdapter);
viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
public void onPageScrollStateChanged(int state) {
}
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
public void onPageSelected(int position) {
Log.i("TAG", "position: " + position);
switch (position) {
case 0:
addingMarker(LocationData.find(LocationData.class, "Category = ? ", "1"));
break;
case 1:
addingMarker(LocationData.find(LocationData.class, "Category = ? ", "2"));
break;
case 2:
addingMarker(LocationData.find(LocationData.class, "Category = ? ", "3"));
break;
}
}
});
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.setupWithViewPager(viewPager);
听起来您的 onPageSelected
回调没有被调用,因为页面实际上并没有改变。我想如果你写了一个 TabLayout.ViewPagerOnTabSelectedListener
的自定义子类,你可以使用 onTabReselected
回调来触发你的刷新,即使那些选定的页面索引没有改变。
您应该可以使用 TabLayout::setOnTabSelectedListener
在您调用 之后安装您的自定义 OnTabSelectedListener
[=15] =].
原答案:
Android 团队更改了一些关于 TabLayout 和 ViewPager 相互通信的方式。 Read the docs。但是事情并没有很好地解释。我在代码中包含了很多注释。希望对您有所帮助。
final ViewPager viewPager = (ViewPager) findViewById(R.id.viewPager);
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabLayout);
Adapter adapter = new Adapter(getSupportFragmentManager());
viewPager.setAdapter(adapter);
// the tabs will get their titles from the adapter and get populated
tabLayout.setTabsFromPagerAdapter(adapter);
// this is done "so that the tab position is kept in sync"
// what it does is when you swipe the fragment in view pager, it updates the tabs
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
// without this listener the tabs would still get updated when fragments are swiped, but .... (read the next comment)
tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
@Override
public void onTabSelected(TabLayout.Tab tab) {
Toast.makeText(MainActivity.this, "tabSelected: " + tab.getText(), Toast.LENGTH_SHORT).show();
// no where in the code it is defined what will happen when tab is tapped/selected by the user
// this is why the following line is necessary
// we need to manually set the correct fragment when a tab is selected/tapped
// and this is the problem in your code
viewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(TabLayout.Tab tab) {
}
@Override
public void onTabReselected(TabLayout.Tab tab) {
Toast.makeText(MainActivity.this, "tabReSelected: " + tab.getText(), Toast.LENGTH_SHORT).show();
// Reload your recyclerView here
}
});
如果您有任何其他问题,请查看此 issue。
编辑 1:2015 年 12 月
不是这个问题的解决方案,但总的来说很有帮助。
tabLayout.setupWithViewPager(viewPager);
这样您就不必担心在选择选项卡时自行设置片段。 tabLayout.setOnTabSelectedListener(..)
在这种情况下不再需要。即处理under the hood。这在您不需要过多控制选项卡时很有用(例如在同一选项卡为 selected/tapped 时重新加载片段)。
更新:2018 年 5 月
tabLayout.setTabsFromPagerAdapter(adapter);
tabLayout.setOnTabSelectedListener(...);
以上两个函数均已弃用。如下图初始化viewpager+tablayout:
viewPager.setAdapter(adapter);
tabLayout.setupWithViewPager(viewPager); // this will automatically bind tab clicks to viewpager fragments
viewPager.addOnPageChangeListener(TabLayout.TabLayoutOnPageChangeListener(tabLayout))
// do additional tab clicks here
// no need to manually set viewpager item based on tab click
tabLayout.addOnTabSelectedListener(...);
我有一个 ViewPager
和 addOnPageChangeListener
。 ViewPager
有 3 个标签视图(tab1、tab2、tab3)。当用户单击 tab2 时,它会加载一些数据(基本上是 RecyclerView
)。此时,如果用户再次点击tab2,我需要重新加载数据,但在这种情况下addOnPageChangeListener
不会被触发。
我的代码:
customPagerAdapter = new CustomPagerAdapter(getSupportFragmentManager(), MainActivity.this);
viewPager.setAdapter(customPagerAdapter);
viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
public void onPageScrollStateChanged(int state) {
}
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
public void onPageSelected(int position) {
Log.i("TAG", "position: " + position);
switch (position) {
case 0:
addingMarker(LocationData.find(LocationData.class, "Category = ? ", "1"));
break;
case 1:
addingMarker(LocationData.find(LocationData.class, "Category = ? ", "2"));
break;
case 2:
addingMarker(LocationData.find(LocationData.class, "Category = ? ", "3"));
break;
}
}
});
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.setupWithViewPager(viewPager);
听起来您的 onPageSelected
回调没有被调用,因为页面实际上并没有改变。我想如果你写了一个 TabLayout.ViewPagerOnTabSelectedListener
的自定义子类,你可以使用 onTabReselected
回调来触发你的刷新,即使那些选定的页面索引没有改变。
您应该可以使用 TabLayout::setOnTabSelectedListener
在您调用 之后安装您的自定义 OnTabSelectedListener
[=15] =].
原答案:
Android 团队更改了一些关于 TabLayout 和 ViewPager 相互通信的方式。 Read the docs。但是事情并没有很好地解释。我在代码中包含了很多注释。希望对您有所帮助。
final ViewPager viewPager = (ViewPager) findViewById(R.id.viewPager);
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabLayout);
Adapter adapter = new Adapter(getSupportFragmentManager());
viewPager.setAdapter(adapter);
// the tabs will get their titles from the adapter and get populated
tabLayout.setTabsFromPagerAdapter(adapter);
// this is done "so that the tab position is kept in sync"
// what it does is when you swipe the fragment in view pager, it updates the tabs
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
// without this listener the tabs would still get updated when fragments are swiped, but .... (read the next comment)
tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
@Override
public void onTabSelected(TabLayout.Tab tab) {
Toast.makeText(MainActivity.this, "tabSelected: " + tab.getText(), Toast.LENGTH_SHORT).show();
// no where in the code it is defined what will happen when tab is tapped/selected by the user
// this is why the following line is necessary
// we need to manually set the correct fragment when a tab is selected/tapped
// and this is the problem in your code
viewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(TabLayout.Tab tab) {
}
@Override
public void onTabReselected(TabLayout.Tab tab) {
Toast.makeText(MainActivity.this, "tabReSelected: " + tab.getText(), Toast.LENGTH_SHORT).show();
// Reload your recyclerView here
}
});
如果您有任何其他问题,请查看此 issue。
编辑 1:2015 年 12 月
不是这个问题的解决方案,但总的来说很有帮助。
tabLayout.setupWithViewPager(viewPager);
这样您就不必担心在选择选项卡时自行设置片段。 tabLayout.setOnTabSelectedListener(..)
在这种情况下不再需要。即处理under the hood。这在您不需要过多控制选项卡时很有用(例如在同一选项卡为 selected/tapped 时重新加载片段)。
更新:2018 年 5 月
tabLayout.setTabsFromPagerAdapter(adapter);
tabLayout.setOnTabSelectedListener(...);
以上两个函数均已弃用。如下图初始化viewpager+tablayout:
viewPager.setAdapter(adapter);
tabLayout.setupWithViewPager(viewPager); // this will automatically bind tab clicks to viewpager fragments
viewPager.addOnPageChangeListener(TabLayout.TabLayoutOnPageChangeListener(tabLayout))
// do additional tab clicks here
// no need to manually set viewpager item based on tab click
tabLayout.addOnTabSelectedListener(...);