qingmei2
3/20/2018 - 3:37 AM

TabLayoutUtils

通过反射动态设置TabLayout下划线的宽度,该方法必须在tabLayout.addTab后调用

public final class TabLayoutUtils {

    private TabLayoutUtils() {
        throw new IllegalStateException("Can't INSTANCE the TabLayoutUtils");
    }

    public static void setIndicatorWidth(final 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();
        }
    }

    public static int dip2px(Context context, float dpValue) {
        final float scale = context.getResources().getDisplayMetrics().density;
        return (int) (dpValue * scale + 0.5f);
    }
}