安卓笔记 TabLayout下划线长度 修改和自定义 TabLayout的tab按钮

工具类代码:
public class TabLayoutUtils {
    /**
     * 此方法必须在这个属性下生效app:tabGravity="center"
     * @param tabLayout
     */
    public static void reflex(final TabLayout tabLayout) {
        tabLayout.post(new Runnable() {
            @Override
            public void run() {
                try {
                    //拿到tabLayout的mTabStrip属性
                    LinearLayout mTabStrip = (LinearLayout) tabLayout.getChildAt(0);

                    int dp10 = AppUtils.dip2px(tabLayout.getContext(), 10);

                    for (int i = 0; i < mTabStrip.getChildCount(); i++) {
                        View tabView = mTabStrip.getChildAt(i);

                        //拿到tabView的mTextView属性  tab的字数不固定一定用反射取mTextView
                        Field mTextViewField;
                        try {
                            mTextViewField = tabView.getClass().getDeclaredField("mTextView");
                        } catch (Exception e) {
                            mTextViewField = tabView.getClass().getDeclaredField("textView"); //安卓28变量名变了
                        }
                        mTextViewField.setAccessible(true);

                        TextView mTextView = (TextView) mTextViewField.get(tabView);

                        tabView.setPadding(0, 0, 0, 0);

                        //因为我想要的效果是   字多宽线就多宽，所以测量mTextView的宽度
                        int width = 0;
                        width = mTextView.getWidth();
                        if (width == 0) {
                            mTextView.measure(0, 0);
                            width = mTextView.getMeasuredWidth();
                        }

                        //设置tab左右间距为10dp  注意这里不能使用Padding 因为源码中线的宽度是根据 tabView的宽度来设置的
                        LinearLayout.LayoutParams params = (LinearLayout.LayoutParams) tabView.getLayoutParams();
                        params.width = width;
                        params.leftMargin = dp10;
                        params.rightMargin = dp10;
                        tabView.setLayoutParams(params);

                        tabView.invalidate();
                    }

                } catch (NoSuchFieldException e) {
                    e.printStackTrace();
                } catch (IllegalAccessException e) {
                    e.printStackTrace();
                }
            }
        });

    }


    /**
     * 设置tab的宽度
     */
    public static void setScaledTabLayout(final TabLayout tb_layout, final int leftDip, final int rightDip , final boolean hideTab) {
        ViewTreeObserver viewTreeObserver = tb_layout.getViewTreeObserver();
        viewTreeObserver.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {

            @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
            @Override
            public void onGlobalLayout() {
                tb_layout.getViewTreeObserver().removeOnGlobalLayoutListener(this);
                LinearLayout mTabStrip = (LinearLayout) tb_layout.getChildAt(0);

                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 < mTabStrip.getChildCount(); i++) {
                    View child = mTabStrip.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();
                }
            }
        });
    }

    /**
     * 设置tab的下划线和文字一样宽度
     * 此方法会忽视这个属性app:tabGravity="center"
     */
    public static void setTabWidthSame(final TabLayout tabs) {
        ViewTreeObserver viewTreeObserver = tabs.getViewTreeObserver();
        viewTreeObserver.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {

            @Override
            public void onGlobalLayout() {
                tabs.getViewTreeObserver().removeOnGlobalLayoutListener(this);
                //拿到tabLayout的mTabStrip属性
                LinearLayout mTabStrip = (LinearLayout) tabs.getChildAt(0);
                int totalWidth = mTabStrip.getMeasuredWidth();
                int tabWidth = totalWidth/mTabStrip.getChildCount();
                for (int i = 0; i < mTabStrip.getChildCount(); i++) {
                    View child = mTabStrip.getChildAt(i);
                    child.setPadding(0, 0, 0, 0);

                    Field mTextViewField = null;
                    int width = 0;
                    try {
                        try {
                            mTextViewField = child.getClass().getDeclaredField("mTextView");
                        } catch (Exception e) {
                            mTextViewField = child.getClass().getDeclaredField("textView"); //安卓28变量名变了
                        }
                        mTextViewField.setAccessible(true);
                        TextView mTextView = (TextView) mTextViewField.get(child);
                        //因为我想要的效果是   字多宽线就多宽，所以测量mTextView的宽度
                        width = mTextView.getWidth();
                        if (width == 0) {
                            mTextView.measure(0, 0);
                            width = mTextView.getMeasuredWidth();
                        }
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                    LinearLayout.LayoutParams params = (LinearLayout.LayoutParams)child.getLayoutParams();
                    params.width = width;
                    params.leftMargin = (tabWidth - width)/2;
                    params.rightMargin = (tabWidth - width)/2;
                    child.setLayoutParams(params);
                    child.invalidate();
                }
            }
        });
    }
}

 

自定义tab样式

mTbLayout.addTab(mTbLayout.newTab().setText(titles[0]), true);
mTbLayout.addTab(mTbLayout.newTab().setText(titles[1]), false);
mTbLayout.addTab(mTbLayout.newTab().setText(titles[2]), false);
mTbLayout.addTab(mTbLayout.newTab().setText(titles[3]), false);
for (int i = 0; i < titles.length; i++) {
    TabLayout.Tab tab = mTbLayout.getTabAt(i);//获得每一个tab

    FrameLayout box = (FrameLayout) LayoutInflater.from(mContext).inflate(R.layout.item_tab_layout, null);
    TextView textView = (TextView) box.findViewById(R.id.tab_text);
    textView.setText(titles[i]);//设置tab上的文字
    tab.setCustomView(box);//给每一个tab设置view
}

 

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