需要改动的地方

1.Menu下面多了一个横线

2.点击变换按钮之后，按钮下面的横线以及字体，还有右边的arrow都变成红色，并且再次点击同一个menu，仍然是红色

解决横线问题

首先在menu_item中增加一个View

 <View

         android:id="@+id/menu_divider"

         android:layout_width="35dp"

         android:layout_height="4dp"

         android:layout_alignLeft="@id/tv_menu_title"

         android:layout_alignRight="@id/tv_menu_title"

         android:layout_below="@id/tv_menu_title"

         android:layout_centerHorizontal="true"

         android:layout_marginTop="4dp"

         android:background="@color/divider_menu"

         android:visibility="invisible" />

在DropDownMenu修改

增加变量

 private boolean mShowMenuDivider;

在init方法中设置mShowMenuDivider = true;

为了当Menu点击选项变化时，改变字体颜色和显示横线，我重写了OnMenuSelectedListener用于监听选择的主Menu改变事件，又增加了一个OnMenuItemSelectedListener监听器，用于监听Menu展开后的点击Item事件

public interface OnMenuSelectedListener {

    public void OnMenuChanged(List<ImageView> mIvMenuArrow, View view, int nowRowIndex);

}

本来我没有加mIvMenuArrow这个参数的，后面会讲为什么增加这个参数

在MainActivity中实现OnMenuSelectedListener接口，重写onMenuChanged方法

观察以下代码

通过循环画出menu的选项页面，并调用监听方法

for (int i = 0; i < mMenuCount; i++) {

                // final View menuDivider;

                final RelativeLayout v = (RelativeLayout) LayoutInflater.from(

                        mContext).inflate(R.layout.menu_item, null, false);

                // menuDivider = v.findViewById(R.id.menu_divider);

                RelativeLayout.LayoutParams parms = new RelativeLayout.LayoutParams(

                        width / mMenuCount, LayoutParams.WRAP_CONTENT);

                v.setLayoutParams(parms);

                TextView tv = (TextView) v.findViewById(R.id.tv_menu_title);

                tv.setTextColor(mMenuTitleTextColor);

                tv.setTextSize(mMenuTitleTextSize);

                if (mDefaultMenuTitle == null || mDefaultMenuTitle.length == 0) {

                    tv.setText(mMenuItems.get(i)[0]);

                } else {

                    tv.setText(mDefaultMenuTitle[i]);

                }

                this.addView(v, i);

                mTvMenuTitles.add(tv);

                RelativeLayout rl = (RelativeLayout) v

                        .findViewById(R.id.rl_menu_head);

                rl.setBackgroundColor(mMenuBackColor);

                mRlMenuBacks.add(rl);

                ImageView iv = (ImageView) v.findViewById(R.id.iv_menu_arrow);

                mIvMenuArrow.add(iv);

                mIvMenuArrow.get(i).setImageResource(mArrow.get(i).get("down"));

                RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) iv

                        .getLayoutParams();

                params.leftMargin = mArrowMarginTitle;

                iv.setLayoutParams(params);

                final int index = i;

                v.setOnClickListener(new OnClickListener() {

                    @Override

                    public void onClick(View view) {

                        Log.i("tanjin", "DropDwonMenu------->OnClick");

                        mMenuList.setAdapter(mMenuAdapters.get(index));

                        if (mMenuAdapters.get(index).getCount() > mShowCount) {

                            View childView = mMenuAdapters.get(index).getView(

                                    0, null, mMenuList);

                            childView.measure(MeasureSpec.makeMeasureSpec(0,

                                    MeasureSpec.UNSPECIFIED),

                                    MeasureSpec.makeMeasureSpec(0,

                                            MeasureSpec.UNSPECIFIED));

                            RelativeLayout.LayoutParams parms = new RelativeLayout.LayoutParams(

                                    LayoutParams.MATCH_PARENT, childView

                                            .getMeasuredHeight() * mShowCount);

                            mMenuList.setLayoutParams(parms);

                        } else {

                            View childView = mMenuAdapters.get(index).getView(

                                    0, null, mMenuList);

                            childView.measure(MeasureSpec.makeMeasureSpec(0,

                                    MeasureSpec.UNSPECIFIED),

                                    MeasureSpec.makeMeasureSpec(0,

                                            MeasureSpec.UNSPECIFIED));

                            RelativeLayout.LayoutParams parms = new RelativeLayout.LayoutParams(

                                    LayoutParams.MATCH_PARENT,

                                    LayoutParams.WRAP_CONTENT);

                            mMenuList.setLayoutParams(parms);

                        }

                        if (mMenuSelectedListener == null && isDebug)

                            Toast.makeText(mContext,

                                    "MenuSelectedListener is  null",

                                    Toast.LENGTH_LONG).show();

                        else {
　　　　　　　　　　　　　　　　　//调用监听方法

                            mMenuSelectedListener.OnMenuChanged(mIvMenuArrow,

                                    view, index);

                        }

                        if (!mShowDivider) {

                            mMenuList.setDivider(null);

                        }

                        mMenuList.setBackgroundColor(mMenuListBackColor);

                        mColumnSelected = index;

                        mTvMenuTitles.get(index).setTextColor(

                                mMenuPressedTitleTextColor);

                        mRlMenuBacks.get(index).setBackgroundColor(

                                mMenuPressedBackColor);

                        mIvMenuArrow.get(index).setImageResource(

                                mArrow.get(index).get("up"));

                        mPopupWindow.showAsDropDown(v);

                    }

                });

            }

在Activity中设置监听器，并重写OnMenuChanged方法

 menu.setMenuSelectedListener(new OnMenuSelectedListener() {

             private ArrayList<Map<String, Integer>> mArrow = new ArrayList<>();

             @Override

             public void OnMenuChanged(List<ImageView> mIvMenuArrow, View view,

                     int nowRowIndex) {

                 // TODO Auto-generated method stub

                 Log.i("tanjin", "MainActivity------>OnMenuChanged");

                 for (int i = 0; i < menu.getChildCount(); i++) {

                     View v = menu.getChildAt(i);

                     v.findViewById(R.id.menu_divider).setVisibility(

                             View.INVISIBLE);

                     ((TextView) v.findViewById(R.id.tv_menu_title))

                             .setTextColor(getResources().getColor(

                                     R.color.default_menu_text));

                     if (i != nowRowIndex) {

                         mIvMenuArrow.get(i).setImageResource(

                                 R.drawable.arrow_down);

                     }

                 }

                 menu.setmArrow(nowRowIndex);

                 view.findViewById(R.id.menu_divider)

                         .setVisibility(View.VISIBLE);

                 TextView tv = (TextView) view.findViewById(R.id.tv_menu_title);

                 tv.setTextColor(getResources().getColor(

                         R.color.default_menu_press_text));

                 Toast.makeText(CollectionActivity.this, " " + nowRowIndex,

                         Toast.LENGTH_SHORT).show();

             }

         });