摘要：
Tablayout应该经常使用，但底部导航栏的长度是固定的，您需要自己更改长度。找了很久，你还没有找到办法。在阅读了官方建议后，您可以通过映射更改所需的长度。事实上，这只是几行代码。请参见代码：public static void setIndicator（Contextcontext，TabLayouttab，intleftDip，intrightDip）｛Class＜？＞tabLayout=ta
关于Tablayout，使用的应该很频繁了，但是底部导航条长短是固定死的，需要自己来改动长短，找了半天没找着方法，看了下官方建议，可以通过映射来修改自己想要的长短，其实也就几行代码的问题，看代码：
public static void setIndicator(Context context, TabLayout tabs, int leftDip, int rightDip) { Class<?> tabLayout = tabs.getClass(); Field tabStrip = null; try { tabStrip = tabLayout.getDeclaredField("mTabStrip"); } catch (NoSuchFieldException e) { e.printStackTrace(); } tabStrip.setAccessible(true); LinearLayout ll_tab = null; try { ll_tab = (LinearLayout) tabStrip.get(tabs); } catch (IllegalAccessException e) { e.printStackTrace(); } int left = (int) (getDisplayMetrics(context).density * leftDip); int right = (int) (getDisplayMetrics(context).density * rightDip); for (int i = 0; i < ll_tab.getChildCount(); i++) { View child = ll_tab.getChildAt(i); child.setPadding(0, 0, 0, 0); LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(0, LinearLayout.LayoutParams.MATCH_PARENT, 1); params.leftMargin = left; params.rightMargin = right; child.setLayoutParams(params); child.invalidate(); } }
leftDip和rightDip是左右间距，根据自己的需要来设置，直接调用即可。
很多同学都遇到问题，这里附上源码，大家可以看看： package com.example.donghe.myrefreshview; import android.app.Activity; import android.content.Context; import android.support.design.widget.TabLayout; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentManager; import android.support.v4.app.FragmentStatePagerAdapter; import android.support.v4.view.ViewPager; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.util.DisplayMetrics; import android.util.TypedValue; import android.view.View; import android.widget.LinearLayout; import android.widget.TableLayout; import java.lang.reflect.Field; public class MainActivity extends AppCompatActivity { private static int TAB_MARGIN_DIP = 11; TabLayout tableLayout; ViewPager viewPager; RankingPagerAdapter adapter; String [] strings = {"皇帝","丞相","尚书","太监"}; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); tableLayout = (TabLayout) findViewById(R.id.tabs_ranking); viewPager = (ViewPager) findViewById(R.id.container_ranking); adapter = new RankingPagerAdapter(getSupportFragmentManager()); viewPager.setAdapter(adapter); tableLayout.setupWithViewPager(viewPager); tableLayout.setTabTextColors(getResources().getColor(R.color.black), getResources().getColor(R.color.red_pre)); tableLayout.setTabsFromPagerAdapter(adapter); setIndicator(this, tableLayout, TAB_MARGIN_DIP, TAB_MARGIN_DIP); } private class RankingPagerAdapter extends FragmentStatePagerAdapter { public RankingPagerAdapter(FragmentManager fm) { super(fm); } @Override public Fragment getItem(int position) { return new FuelFragment().newInstance(position, strings[position]); } @Override public int getCount() { return strings.length; } @Override public CharSequence getPageTitle(int position) { return strings[position]; } } public static void setIndicator(Context context, TabLayout tabs, int leftDip, int rightDip) { Class<?> tabLayout = tabs.getClass(); Field tabStrip = null; try { tabStrip = tabLayout.getDeclaredField("mTabStrip"); } catch (NoSuchFieldException e) { e.printStackTrace(); } tabStrip.setAccessible(true); LinearLayout ll_tab = null; try { ll_tab = (LinearLayout) tabStrip.get(tabs); } catch (IllegalAccessException e) { e.printStackTrace(); } int left = (int) (getDisplayMetrics(context).density * leftDip); int right = (int) (getDisplayMetrics(context).density * rightDip); for (int i = 0; i < ll_tab.getChildCount(); i++) { View child = ll_tab.getChildAt(i); child.setPadding(0, 0, 0, 0); LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(0, LinearLayout.LayoutParams.MATCH_PARENT, 1); params.leftMargin = left; params.rightMargin = right; child.setLayoutParams(params); child.invalidate(); } } public static DisplayMetrics getDisplayMetrics(Context context) { DisplayMetrics metric = new DisplayMetrics(); ((Activity) context).getWindowManager().getDefaultDisplay().getMetrics(metric); return metric; } public static float getPXfromDP(float value, Context context) { return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, value, context.getResources().getDisplayMetrics()); } }
Fragment：
package com.example.donghe.myrefreshview; import android.os.Bundle; import android.support.annotation.Nullable; import android.support.v4.app.Fragment; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.TextView; /** * Created by dong.he on 2016/12/9. */ public class FuelFragment extends Fragment { public static String TAB_POSITION; public static String TAB_NAME; private String tabId; private int tabPosition; public FuelFragment() { } public static Fragment newInstance(int tabPosition, String tabName) { FuelFragment fragment = new FuelFragment(); Bundle bundle = new Bundle(); bundle.putInt(TAB_POSITION, tabPosition); bundle.putString(TAB_NAME, tabName); fragment.setArguments(bundle); return fragment; } @Nullable @Override public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { return inflater.inflate(R.layout.layout, container, false); } @Override public void onActivityCreated(@Nullable Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); tabPosition = getArguments().getInt(TAB_POSITION, 0); tabId = getArguments().getString(TAB_NAME); ((TextView) getView().findViewById(R.id.text)).setText(tabId); } }
布局：
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <android.support.design.widget.TabLayout android:id="@+id/tabs_ranking" android:layout_width="match_parent" android:layout_height="wrap_content" app:tabGravity="fill" app:tabIndicatorColor="@color/red_pre" app:tabMode="scrollable" /> <android.support.v4.view.ViewPager android:id="@+id/container_ranking" android:layout_width="match_parent" android:layout_height="match_parent" /> </LinearLayout>
有问题的欢迎垂询。
