这篇文章将为大家详细讲解有关怎么在Android应用中利用PopuWindow实现一个下拉列表功能，文章内容质量较高，因此小编分享给大家做个参考，希望大家阅读完这篇文章后对相关知识有一定的了解。
基础依赖，由于下拉列表是用RecycleView实现，然后控件初始化用到ButterKnife，所以要在app的gradle中添加相关依赖：
//RecycleView compile 'com.android.support:recyclerview-v7:25.2.0' //butterKnife compile 'com.jakewharton:butterknife:8.5.1' //这条千万不能忘记!! annotationProcessor 'com.jakewharton:butterknife-compiler:8.5.1'
第一步，不言而喻，肯定是上BasePopupWindow代码：
/***
* PopupWindow基类
*
* @author pei
* @version 1.0
* @cretae 2016-7-21
* @注：若要popwindow点击外部消失，则设置 this.setFocusable(true)
* 若要popwindow点击外部不消失，不做setFocusable设置，也不要设置成this.setFocusable(false)
*
*/
public abstract class BasePopupWindow extends PopupWindow {
protected View mLayoutView;
protected int mLayoutId;
protected Context mContext;
protected int mWidth;
protected int mHeight;
public BasePopupWindow(int width, int height, int layoutId, Context context) {
this.mWidth = width;
this.mHeight = height;
this.mLayoutId = layoutId;
this.mContext = context;
mLayoutView = LayoutInflater.from(context).inflate(mLayoutId, null);
setWindow();
}
/** PopupWindow基本设置 **/
protected void setWindow() {
this.setContentView(mLayoutView);
this.setWidth(mWidth);
this.setHeight(mHeight);
// this.setFocusable(true);// 可点击
// 实例化一个ColorDrawable颜色为半透明(半透明遮罩颜色代码#66000000)
ColorDrawable dw = new ColorDrawable(Color.TRANSPARENT);
this.setBackgroundDrawable(dw);
}
/** PopupWindow背景设置 **/
protected void setBackground(int color) {
// 实例化一个ColorDrawable颜色为半透明
ColorDrawable dw = new ColorDrawable(color);
this.setBackgroundDrawable(dw);
}
protected abstract void initView();
protected abstract void initData();
protected abstract void setListener();
/** PopupWindow点击间隙处理，根据实际情况重写 **/
protected void onTouchdimiss() {
// mMenuView添加OnTouchListener监听判断获取触屏位置如果在选择框外面则销毁弹出框
mLayoutView.setOnTouchListener(new OnTouchListener() {
@Override
public boolean onTouch(View view, MotionEvent event) {
// int height = mLayoutView.getTop();
// int y = (int) event.getY();
// if (event.getAction() == MotionEvent.ACTION_UP) {
// if (y < height) {
// dismiss();
// }
// }
return false;
}
});
}
/**
* 显示在控件正上方
*
* @param view
* 依赖的控件
* @param marginDp
* 设置的间距(直接写数字即可，已经做过dp2px转换)
*/
public void showAtLocationTop(View view, float marginDp) {
mLayoutView.measure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);
int popupWidth = mLayoutView.getMeasuredWidth();
int popupHeight = mLayoutView.getMeasuredHeight();
int[] location = new int[2];
view.getLocationOnScreen(location);
showAtLocation(view, Gravity.NO_GRAVITY, (location[0] + view.getWidth() / 2) - popupWidth / 2, location[1] - popupHeight - dp2px(marginDp));
update();
}
/**
* 显示在控件正下方
*
* @param view
* 依赖的控件
* @param marginDp
* 设置的间距(直接写数字即可，已经做过dp2px转换)
*/
public void showAtLocationGravityBottom(View view, float marginDp) {
mLayoutView.measure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);
int popupWidth = mLayoutView.getMeasuredWidth();
int popupHeight = mLayoutView.getMeasuredHeight();
int[] location = new int[2];
view.getLocationOnScreen(location);
showAtLocation(view, Gravity.NO_GRAVITY, (location[0]+view.getWidth()/2)-popupWidth/2,
location[1]+view.getHeight()+dp2px(marginDp));
update();
}
/**显示在控件下方
*
* @param view 依赖的控件
* @param marginDp 设置的间距(直接写数字即可，已经做过dp2px转换)
*/
public void showAtLocationBottom(View view, float marginDp){
showAsDropDown(view, 0, dp2px(marginDp));
update();
}
/**
* 显示在控件左方
*
* @param view
* 依赖的控件
* @param marginDp
* 设置的间距(直接写数字即可，已经做过dp2px转换)
*/
public void showAtLocationLeft(View view, float marginDp) {
mLayoutView.measure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);
int popupWidth = mLayoutView.getMeasuredWidth();
int popupHeight = mLayoutView.getMeasuredHeight();
int[] location = new int[2];
view.getLocationOnScreen(location);
showAtLocation(view, Gravity.NO_GRAVITY, location[0] - popupWidth - dp2px(marginDp), (location[1] + view.getHeight() / 2) - popupHeight / 2);
update();
}
/**
* 显示在控件右方
*
* @param view
* 依赖的控件
* @param marginDp
* 设置的间距(直接写数字即可，已经做过dp2px转换)
*/
public void showAtLocationRight(View view, float marginDp) {
mLayoutView.measure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);
int popupWidth = mLayoutView.getMeasuredWidth();
int popupHeight = mLayoutView.getMeasuredHeight();
int[] location = new int[2];
view.getLocationOnScreen(location);
showAtLocation(view, Gravity.NO_GRAVITY, location[0] + view.getWidth() + dp2px(marginDp), (location[1] + view.getHeight() / 2) - popupHeight / 2);
update();
}
/** dp转px **/
private int dp2px(float dpVal) {
return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dpVal, mContext.getResources().getDisplayMetrics());
}
/** 通过id获得view **/
@SuppressWarnings("unchecked")
protected <T extends View> T getView(int viewId) {
View view = null;
if (mLayoutView == null) {
mLayoutView = LayoutInflater.from(mContext).inflate(mLayoutId, null);
}
view = mLayoutView.findViewById(viewId);
return (T) view;
}
}第二步，写一个OrderPop继承于BasePopupWindow：
/**
* Instruction:下拉列表Pop
* <p>
* Author:pei
* Date: 2017/6/28
* Description:
*/
public class OrderPop extends BasePopupWindow{
private RecyclerView mRecyclerView;
private List<String>mDatas;
private ManagerPopuAdapter<String> managerPopuAdapter;
public OrderPop(Context context, List<String>datas) {
super(ScreenUtil.dp2px(100,context), ScreenUtil.dp2px(150,context), R.layout.pop_order, context);
this.mDatas=datas;
initView();
initData();
setListener();
}
@Override
protected void initView() {
mRecyclerView=getView(R.id.recycler_view);
}
@Override
protected void initData() {
setFocusable(true);
setAnimationStyle(R.style.popuwindow_up_style);//popuwindow显示隐藏的动画
mRecyclerView.setHasFixedSize(true);
mRecyclerView.setLayoutManager(new LinearLayoutManager(mContext));
managerPopuAdapter = new ManagerPopuAdapter<String>(mContext, mDatas);
mRecyclerView.setAdapter(managerPopuAdapter);
}
@Override
protected void setListener(){
}
public ManagerPopuAdapter getAdapter(){
return managerPopuAdapter;
}
public void notifyDataSetChanged(){
if(managerPopuAdapter!=null){
managerPopuAdapter.notifyDataSetChanged();
}
}
public void setCurrentIndex(int position){
if(managerPopuAdapter!=null){
managerPopuAdapter.setIndex(position);
}
}
}OrderPop类中涉及到的内容挺多，以下将细细讲解。
1.--- 声明中涉及到RecycleView的一个适配器ManagerPopuAdapter,其代码如下:
/**
* Instruction: Orderpop的适配器
* <p>
* Author:pei
* Date: 2017/6/29
* Description:
*/
public class ManagerPopuAdapter<T> extends RecyclerView.Adapter {
protected Context mContext;
protected View mLayoutView;
protected List<T> mData;
private ViewHolder mViewHolder;
protected OnRecyclerItemClickListener mOnRecyclerItemClickListener;
private int mIndex;
public void setOnRecyclerItemClickListener(OnRecyclerItemClickListener onRecyclerItemClickListener) {
this.mOnRecyclerItemClickListener = onRecyclerItemClickListener;
}
public ManagerPopuAdapter(Context context, List<T> data) {
this.mContext = context;
this.mData = data;
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
//注：不可使用view=LayoutInflater.from(mContext).inflate(R.layout.item_layout，null);不然会报错
mLayoutView = LayoutInflater.from(mContext).inflate(R.layout.item_popu_order_layout, parent, false);
return new ViewHolder(mLayoutView);
}
@Override
public int getItemViewType(int position) {
return super.getItemViewType(position);
}
@Override
public int getItemCount() {
return mData == null ? 0 : mData.size();
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
mViewHolder = ((ViewHolder) holder);
initData(position);
setListener(position);
}
private void initData(int position) {
String content =mData.get(position).toString();
mViewHolder.tvContent.setText(content);
if(mIndex==position){
mViewHolder.tvContent.setSelected(true);
}else{
mViewHolder.tvContent.setSelected(false);
}
}
private void setListener(final int position) {
mViewHolder.tvContent.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mOnRecyclerItemClickListener != null) {
mOnRecyclerItemClickListener.onRecyclerClick(position);
}
}
});
}
public void setIndex(int index){
this.mIndex=index;
}
class ViewHolder extends RecyclerView.ViewHolder {
TextView tvContent;
public ViewHolder(View view) {
super(view);
tvContent=(TextView)view.findViewById(R.id.tv_content);
}
}
public interface OnRecyclerItemClickListener {
void onRecyclerClick(int position);
}
}2.--- ManagerPopuAdapter.java对应的layout----- item_popu_order_layout.xml代码：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="3dp"
android:layout_marginBottom="3dp">
<TextView
android:id="@+id/tv_content"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:lineSpacingExtra="1dp"
android:lineSpacingMultiplier="1.0"
android:layout_marginLeft="2dp"
android:layout_marginRight="2dp"
android:padding="3dp"
android:background="@drawable/manager_fragment_popu_bg"
android:textColor="@drawable/text_color_bg"
android:textSize="12sp"/>
</LinearLayout>3.--- item_popu_order_layout.xml中android:background="@drawable/manager_fragment_popu_bg"对应的drawable文件为：
<?xml version="1.0" encoding="utf-8"?> <selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:drawable="@drawable/manager_fragment_popu_pressed" android:state_selected="true" /> <item android:drawable="@drawable/manager_fragment_popu_normal" android:state_selected="false"/> </selector>
manager_fragment_popu_pressed和manager_fragment_popu_normal对应的其实都是纯颜色xml文件。
manager_fragment_popu_pressed.xml代码如下：
<?xml version="1.0" encoding="utf-8"?> <shape xmlns:android="http://schemas.android.com/apk/res/android" > <solid android:color="@color/color_f5cc1d"></solid> </shape>
manager_fragment_popu_normal.xml代码如下：
<?xml version="1.0" encoding="utf-8"?> <shape xmlns:android="http://schemas.android.com/apk/res/android" > <solid android:color="@color/transparent"></solid> </shape>
也许有的同学会问android:background="@drawable/manager_fragment_popu_bg文件中为什恶魔不直接用color属性设置背景切换，而要用color写个drawable供调用，其实我一开始也是这样弄的，无奈报错，具体原因不详，知道的同学可以回复下，此处不做重点。
4.--- item_popu_order_layout.xml中android:textColor="@drawable/text_color_bg"对应的drawable文件如下：
<?xml version="1.0" encoding="utf-8"?> <selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:color="@color/color_ff5b0a" android:state_selected="true"/> <item android:color="@color/black" android:state_selected="false"/> </selector>
5.---讲讲OrderPop的构造函数
public OrderPop(Context context, List<String>datas) {
super(ScreenUtil.dp2px(100,context), ScreenUtil.dp2px(150,context), R.layout.pop_order, context);
this.mDatas=datas;
initView();
initData();
setListener();
}这里我其实是图方便，所以直接传了个固定宽度 ScreenUtil.dp2px(100,context) 进去了，实际开发中因为是点击某个控件然后在控件下面显示出来，那么应该传那个控件的宽度。
6.---OrderPop的layout布局pop_order.xml代码如下：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/color_c0c0c0">
<android.support.v7.widget.RecyclerView
android:id="@+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical"
android:scrollbarThumbVertical="@color/blue"
android:scrollbarStyle="outsideOverlay"/>
</LinearLayout>其中，android:scrollbars="vertical"是设置滚动条方向，android:scrollbarThumbVertical="@color/blue"是设置滚动条颜色，android:scrollbarStyle="outsideOverlay"设置滚动条样式
7.---讲讲OrderPop的显隐动画问题
在OrderPop类中的initData()方法中涉及到这样一行代码：
涉及到popuwindow的显隐动画问题，大家可以参考的前言中提到的popuwindow的基本使用文章，这里就不废话了。
第三步，OrderPop写好了，就该看看在MainActivity中是怎么调用的了，贴出MainActivity的代码：
/**
* Created by Admin on 2017/5/19.
*/
public class MainActivity extends BaseActivity implements View.OnClickListener{
@BindView(R.id.tv_order)
TextView mTvOrder;
private static final int DEFAULT_INDEX=0;
private List<String> mOrderList=new ArrayList<>();
private OrderPop mOrderPop;
@Override
protected int getContentViewId() {
return R.layout.activity_main;
}
@Override
protected void initData() {
initOrderTextBar();
}
/**订单列表**/
private void initOrderTextBar(){
mOrderList.add("野蛮人");
mOrderList.add("圣骑士");
mOrderList.add("亚马逊");
mOrderList.add("死灵法师");
mOrderList.add("法师");
mOrderList.add("德鲁伊");
mOrderList.add("刺客");
mOrderPop=new OrderPop(mContext,mOrderList);
setBarContent(mTvOrder,mOrderList,DEFAULT_INDEX);
mOrderPop.setOnDismissListener(new PopupWindow.OnDismissListener() {
@Override
public void onDismiss(){
mTvOrder.setSelected(false);
}
});
//mOrderPop项点击事件
mOrderPop.getAdapter().setOnRecyclerItemClickListener(new ManagerPopuAdapter.OnRecyclerItemClickListener() {
@Override
public void onRecyclerClick(int position) {
showShortToast(mOrderList.get(position));
//更新mTvOrder显示内容
setBarContent(mTvOrder,mOrderList,position);
//更新mOrderPop视图选中背景
mOrderPop.setCurrentIndex(position);
mOrderPop.notifyDataSetChanged();
}
});
}
@Override
protected void setListener() {
mTvOrder.setOnClickListener(this);
}
@Nullable
@Override
protected BasePresenter getPresenter() {
return null;
}
@Override
protected void onDestroy(){
super.onDestroy();
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.tv_order:
if(mOrderPop!=null&&!mOrderPop.isShowing()){
mTvOrder.setSelected(true);//控制mTvOrder变色
mOrderPop.showAtLocationGravityBottom(mTvOrder,3);//显示mOrderPop
//更新mOrderPop视图选中背景
mOrderPop.setCurrentIndex(getIndexByTag(mTvOrder));
mOrderPop.notifyDataSetChanged();
}
break;
default:
break;
}
}
private void setBarContent(TextView textView,List<String>data,int position){
textView.setTag(position);
textView.setText(data.get(position).toString());
}
private int getIndexByTag(TextView textView){
int index=DEFAULT_INDEX;
Object obj=textView.getTag();
if(obj!=null){
try {
index=Integer.valueOf(obj.toString());
} catch (NumberFormatException e) {
e.printStackTrace();
}
}
return index;
}
}MainActivity对应的布局activity_main.xml代码如下：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/white"
android:gravity="center"
android:orientation="vertical">
<TextView
android:id="@+id/tv_order"
android:layout_width="80dp"
android:layout_height="wrap_content"
android:lineSpacingExtra="1dp"
android:lineSpacingMultiplier="1.0"
android:paddingLeft="5dp"
android:paddingRight="5dp"
android:drawableRight="@drawable/manager_fragment_order_bg"
android:textColor="@drawable/text_color_bg"
android:textSize="14sp"/>
</LinearLayout>android:drawableRight="@drawable/manager_fragment_order_bg"中manager_fragment_order_bg.xml对应的代码如下：
<?xml version="1.0" encoding="utf-8"?> <selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:drawable="@mipmap/ic_drop_up" android:state_selected="true" /> <item android:drawable="@mipmap/ic_drop_down" android:state_selected="false"/> </selector>
ic_drop_up和ic_drop_down对应的分别是一张箭头向上的图片和一张箭头向下的图片，这里就不多说了。
android:textColor="@drawable/text_color_bg"的话是设置文字选中和未被选中时显示的颜色，在上面的第二步第四条已经讲过了，这里就不说了。
关于怎么在Android应用中利用PopuWindow实现一个下拉列表功能就分享到这里了，希望以上内容可以对大家有一定的帮助，可以学到更多知识。如果觉得文章不错，可以把它分享出去让更多的人看到。
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