Android中修改TabLayout底部导航条Indicator长短的方法

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。