TabLayout +ViewPager+Fragment 组合
1. tabLayout的使用
- 布局:
<android.support.design.widget.TabLayout
android:id="@+id/tab"
android:layout_width="match_parent"
android:layout_height="?actionBarSize">
<android.support.design.widget.TabItem
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Tab1" />
<android.support.design.widget.TabItem
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Tab2"/>
<android.support.design.widget.TabItem
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Tab3" />
<android.support.design.widget.TabItem
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Tab4" />
</android.support.design.widget.TabLayout>
- 或者使用代码添加:
TabLayout tabLayout = findViewById(R.id.tab);
TabLayout.Tab tab = tabLayout.newTab();
tab.setText("Tab1");
//添加tab
tabLayout.addTab(tab);
//删除tab
tabLayout.removeTab(tab);
tabLayout.removeTabAt(0);
//删除全部tab
tabLayout.removeAllTabs();
效果图:
image.png
- 常用属性:
-
显示模式
可滑动:app:tabMode="scrollable"
固定:app:tabMode="fixed"
-
指示器选项
指示器高度 :app:tabIndicatorHeight="10dp"
指示器颜色 :app:tabIndicatorColor="@color/colorPrimary"
-
文字选项
选择的Tab的文字颜色:app:tabSelectedTextColor="#ffffff"
未选择的Tab文字颜色:app:tabTextColor="#000000"
-
文字样式:
app:tabTextAppearance="@style/Base.TextAppearance.AppCompat.Large"
-
背景设置(两者没什么区别)
android:background="@color/colorAccent"
app:tabBackground="@color/colorPrimary"
-
标签距离
app:tabPaddingStart="10dp"
app:tabPaddingBottom="10dp"
app:tabPadding="10dp"
app:tabPaddingEnd="10dp"
app:tabPaddingTop="10dp"
-
对齐方式
居中显示:app:tabGravity="center"
填充:app:tabGravity="fill"
偏移:app:tabContentStart="200dp"
(从左边开始偏移距离, 必须是可滑动的模式 scrollable) -
标签宽度限制
最大宽度:app:tabMaxWidth="50dp"
最小宽度:app:tabMinWidth="100dp"
2. TabLayout + ViewPager + Fragment
示例:
tabLayout包含4个tab,每个tab对应一个单独的fragment
fragment代码(布局中仅包含一个textView)
public class MainFragment extends Fragment {
TextView mTextView;
public static MainFragment newInstance(String title) {
MainFragment mainFragment = new MainFragment();
Bundle bundle = new Bundle();
bundle.putString("title", title);
mainFragment.setArguments(bundle);
return mainFragment;
}
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_view, container, false);
mTextView = view.findViewById(R.id.textView);
mTextView.setText((CharSequence) getArguments().get("title"));
return view;
}
}
添加viewPager的adapter
class ViewPagerAdapter extends FragmentStatePagerAdapter{
List<Fragment> mFragments;
String[] mTitles;
public ViewPagerAdapter(FragmentManager fm, List<Fragment> fragments, String[] titles) {
super(fm);
mFragments = fragments;
mTitles = titles;
}
@Override
public Fragment getItem(int position) {
return mFragments.get(position);
}
@Override
public int getCount() {
return mFragments.size();
}
@Nullable
@Override
public CharSequence getPageTitle(int position) {
return mTitles[position];
}
}
activity中:
mTab = findViewById(R.id.tab);
mViewPager = findViewById(R.id.viewpager);
String[] titles = {"TAB1", "TAB2", "TAB3", "TAB4"};
Fragment fragment1 = MainFragment.newInstance(titles[0]);
Fragment fragment2 = MainFragment.newInstance(titles[1]);
Fragment fragment3 = MainFragment.newInstance(titles[2]);
Fragment fragment4 = MainFragment.newInstance(titles[3]);
List<Fragment> fragments = new ArrayList<>();
fragments.add(fragment1);
fragments.add(fragment2);
fragments.add(fragment3);
fragments.add(fragment4);
ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager(), fragments, titles);
mViewPager.setAdapter(adapter);
mTab.setupWithViewPager(mViewPager);
Screenrecorder-2018-11-08-17-26-05-755.gif
2. 使用图标的tabItem
tabItem有icon属性,可以在布局中直接设置:
<android.support.design.widget.TabLayout
android:id="@+id/tab_layout"
android:layout_width="match_parent"
android:layout_height="50dp"
app:tabIndicatorHeight="0dp"
app:tabMode="fixed" >
<android.support.design.widget.TabItem
android:icon="@drawable/tab_item_icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<android.support.design.widget.TabItem
android:icon="@drawable/tab_item_icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<android.support.design.widget.TabItem
android:icon="@drawable/tab_item_icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</android.support.design.widget.TabLayout>
但是这样有个问题,图标太小,没找到可以调整图标大小的办法。显示效果不好。
这里我们可以使用自定义view 的方式。
修改布局:去掉tabItem,改为动态添加。
<android.support.design.widget.TabLayout
android:id="@+id/tab_layout"
android:layout_width="match_parent"
android:layout_height="50dp"
app:tabIndicatorHeight="0dp"
app:tabMode="fixed" />
添加自定义布局:tabitem_icon_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:gravity="center"
android:layout_height="match_parent">
<ImageView
android:src="@drawable/tab_item_icon"
android:id="@+id/icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
图标资源:tab_item_icon.xml
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="@drawable/ic_home_blue_24dp" android:state_selected="true" />
<item android:drawable="@drawable/ic_home_black_24dp" />
</selector>
activity中动态添加:
private void initTab() {
//添加底部tab
for (int i = 0; i < 4; i++) {
View view = getLayoutInflater().inflate(R.layout.tabitem_icon_layout, null);
view.findViewById(R.id.icon).setBackgroundResource(R.drawable.tab_item_icon);
mTabLayout.addTab(mTabLayout.newTab().setCustomView(view));
}
}
这样就达到了我们的效果
image.png
问题:与viewPager的关联
如果用上面提到的方法:
mTabLayout.setupWithViewPager(mViewPager);
我们设置的自定义布局就没有了,tabItem都变成文字了。
可以采用以下方式进行关联:
mTabLayout.addOnTabSelectedListener(new TabLayout.ViewPagerOnTabSelectedListener(mViewPager));
mViewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(mTabLayout));