标签：还需要 des current com screens track bsp mtab param
TabLayout相信大家都用过，2015年Google大会上发布了新的Android Support Design库里面包含了很多新的控件，其中就包含TabLayout，它可以配合ViewPager完成很好的效果。
一种类似于今日头条指示器，根据ViewPager的页面滑动，文字逐渐变色。
今日头条的顶部tab导航效果的实现，我们一般会用RadioGroup+Fragment+ViewPager来实现，适配器繁多，代码量大，今天我们来介绍TabLayout的使用。TabLayout为Android的Design库中的一个控件。首先我们来看一下运行的效果图：
先看下效果
因为是继承TabLayout，所以用法跟TabLayout一模一样
//隐藏Indicator mTab.setSelectedTabIndicatorHeight(0); //设置左右内边距 mTab.setTabPaddingLeftAndRight(10,10); mTab.setupWithViewPager(mViewPager);
ColorTrackLayout主要是继承了TabLayout，对它做了一些扩展。
既然是随着页面的滑动文字颜色渐变那么肯定少不了ViewPager的页面监听，这个在我们调用setupWithViewPager的时候TabLayout就已经添加监听。
private void setupWithViewPager(@Nullable final ViewPager viewPager, boolean autoRefresh, boolean implicitSetup) { .... if (viewPager != null) { mViewPager = viewPager; // Add our custom OnPageChangeListener to the ViewPager if (mPageChangeListener == null) { //添加了滑动监听 mPageChangeListener = new TabLayoutOnPageChangeListener(this); } mPageChangeListener.reset(); viewPager.addOnPageChangeListener(mPageChangeListener); // Now we‘ll add a tab selected listener to set ViewPager‘s current item mCurrentVpSelectedListener = new ViewPagerOnTabSelectedListener(viewPager); addOnTabSelectedListener(mCurrentVpSelectedListener); final PagerAdapter adapter = viewPager.getAdapter(); if (adapter != null) { // Now we‘ll populate ourselves from the pager adapter, adding an observer if // autoRefresh is enabled setPagerAdapter(adapter, autoRefresh); } // Add a listener so that we‘re notified of any adapter changes if (mAdapterChangeListener == null) { mAdapterChangeListener = new AdapterChangeListener(); } mAdapterChangeListener.setAutoRefresh(autoRefresh); viewPager.addOnAdapterChangeListener(mAdapterChangeListener); // Now update the scroll position to match the ViewPager‘s current item setScrollPosition(viewPager.getCurrentItem(), 0f, true); } else { // We‘ve been given a null ViewPager so we need to clear out the internal state, // listeners and observers mViewPager = null; setPagerAdapter(null, false); } .... }
创建了mPageChangeListener并添加了监听
所以我们必须要重写setupWithViewPager删除掉原来的监听，换成我们自己的监听
mPageChangeListener = new TabLayoutOnPageChangeListener(this); @Override public void setupWithViewPager(@Nullable ViewPager viewPager, boolean autoRefresh) { super.setupWithViewPager(viewPager, autoRefresh); try { //通过反射找到mPageChangeListener Field field = TabLayout.class.getDeclaredField("mPageChangeListener"); field.setAccessible(true); TabLayoutOnPageChangeListener listener = (TabLayoutOnPageChangeListener) field.get(this); if (listener != null) { //删除自带监听 viewPager.removeOnPageChangeListener(listener); mPageChangeListenter = new ColorTrackTabLayoutOnPageChangeListener(this); mPageChangeListenter.reset(); viewPager.addOnPageChangeListener(mPageChangeListenter); } } catch (Exception e) { e.printStackTrace(); } }
还需要做的一点就是把TabLayout每一个的Tab布局替换成我们的。怎么替换呢？重写addTab，在添加的时候改成我们的布局
@Override public void addTab(@NonNull Tab tab, int position, boolean setSelected) { ColorTrackView colorTrackView = new ColorTrackView(getContext()); colorTrackView.setProgress(setSelected ? 1 : 0); colorTrackView.setText(tab.getText() + ""); colorTrackView.setTextSize(mTabTextSize); colorTrackView.setTag(position); colorTrackView.setTextChangeColor(mTabSelectedTextColor); colorTrackView.setTextOriginColor(mTabTextColor); LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT); colorTrackView.setLayoutParams(layoutParams); tab.setCustomView(colorTrackView); super.addTab(tab, position, setSelected); if (position == 0) { //默认选中第一个 setSelectedView(position); } setTabWidth(position, colorTrackView); }
其关键就是将我们的布局利用setCustomView方法来设置上去。
源码链接 https://github.com/DingXianSen/DcColorTabLayout
自适应 Tab 宽度可以滑动文字逐渐变色的 TabLayout(仿今日头条顶部导航)
标签：还需要 des current com screens track bsp mtab param
原文地址：http://www.cnblogs.com/dingxiansen/p/7649930.html
