前言

对于Tablayout相信大家都不陌生，在开发中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>

总结

以上就是这篇文章的全部内容了，希望本文的内容对大家的学习或者工作能带来一定的帮助，如果有疑问大家可以留言交流，谢谢大家对的支持。