TabLayout 改变下标的宽度

在使用TabLayout的时候，往往需要改变下标的宽高，高度比较好设置，直接设置属性  ：

 app:tabIndicatorHeight="1.5dp" 

 

但是宽度在不自定义tab的情况下似乎并没有直接提供相关的属性，经过查阅自己写个方法设置才能实现效果，代码如下：

public void setIndicator(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 llTab = null;
        try {
            llTab = (LinearLayout) tabStrip.get(tabs);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }

        int left = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, leftDip, Resources.getSystem().getDisplayMetrics());
        int right = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, rightDip, Resources.getSystem().getDisplayMetrics());

        for (int i = 0; i < llTab.getChildCount(); i++) {
            View child = llTab.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();
        }
    }

然后调用这个方法改变下标的宽度:

 //改变下标宽度
        mTabLayout.post(new Runnable() {
            @Override
            public void run() {
                setIndicator(mTabLayout,30,30);
            }
        });

另：改变tablayout上字体的大小需要在styles.xml里设置

<style name="CustomTabLayoutTextAppearance" parent="TextAppearance.Design.Tab">
        <item name="android:textSize">14sp</item>
        <item name="android:textAllCaps">false</item>
    </style>

然后在xml里引用：

app:tabTextAppearance="@style/CustomTabLayoutTextAppearance"