android添加购物车动画实现

%title插图%num

商品列表Adapter

import android.content.Context;
import android.graphics.drawable.Drawable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.LinearLayout;
/**
* 商品列表Adapter
* @author antkingwei
*
*/
public class GoodAdapter extends BaseAdapter{
private Context mContext;
private LayoutInflater layoutInflater;
private HolderClickListener mHolderClickListener;
final class ViewHolder {
ImageView imgview;
Button button;
}
public GoodAdapter(Context context){
this.mContext = context;
layoutInflater = LayoutInflater.from(mContext);
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return 16;
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return null;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
final int selectedId = position;
final ViewHolder viewHolder;
if(convertView ==null){
viewHolder = new ViewHolder();
convertView = layoutInflater.inflate(R.layout.adapter_listview, null);
viewHolder.imgview = (ImageView)convertView.findViewById(R.id.item_img);
viewHolder.button = (Button)convertView.findViewById(R.id.item_button);
convertView.setTag(viewHolder);
}else{
viewHolder =(ViewHolder)convertView.getTag();
}
viewHolder.button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(mHolderClickListener!=null){
int[] start_location = new int[2];
viewHolder.imgview.getLocationInWindow(start_location);//获取点击商品图片的位置
Drawable drawable = viewHolder.imgview.getDrawable();//复制一个新的商品图标
mHolderClickListener.onHolderClick(drawable,start_location);
}
}
});
return convertView;
}
public void SetOnSetHolderClickListener(HolderClickListener holderClickListener){
this.mHolderClickListener = holderClickListener;
}
public interface HolderClickListener{
public void onHolderClick(Drawable drawable,int[] start_location);
}
}

活动类

package com.example.addshopcart;
import com.example.addshopcart.GoodAdapter.HolderClickListener;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.app.Activity;
import android.content.Context;
import android.graphics.drawable.Drawable;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.Animation;
import android.view.animation.Animation.AnimationListener;
import android.view.animation.AnimationSet;
import android.view.animation.RotateAnimation;
import android.view.animation.ScaleAnimation;
import android.view.animation.TranslateAnimation;
import android.widget.Button;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.ListView;
/**
*
* @author antkingwei
*
*/
public class MainActivity extends Activity {
private ListView listView;
private Button cart_btn;
private GoodAdapter goodAdapter;
//动画时间
private int AnimationDuration = 1000;
//正在执行的动画数量
private int number = 0;
//是否完成清理
private boolean isClean = false;
private FrameLayout animation_viewGroup;
private Handler myHandler = new Handler(){
public void handleMessage(Message msg){
switch(msg.what){
case 0:
//用来清除动画后留下的垃圾
try{
animation_viewGroup.removeAllViews();
}catch(Exception e){
}
isClean = false;
break;
default:
break;
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView)this.findViewById(R.id.listview);
cart_btn = (Button)this.findViewById(R.id.button);
animation_viewGroup = createAnimLayout();
goodAdapter = new GoodAdapter(this);
goodAdapter.SetOnSetHolderClickListener(new HolderClickListener(){
@Override
public void onHolderClick(Drawable drawable,int[] start_location) {
// TODO Auto-generated method stub
doAnim(drawable,start_location);
}
});
listView.setAdapter(goodAdapter);
}
private void doAnim(Drawable drawable,int[] start_location){
if(!isClean){
setAnim(drawable,start_location);
}else{
try{
animation_viewGroup.removeAllViews();
isClean = false;
setAnim(drawable,start_location);
}catch(Exception e){
e.printStackTrace();
}
finally{
isClean = true;
}
}
}
/**
* @Description: 创建动画层
* @param
* @return void
* @throws
*/
private FrameLayout createAnimLayout(){
ViewGroup rootView = (ViewGroup)this.getWindow().getDecorView();
FrameLayout animLayout = new FrameLayout(this);
FrameLayout.LayoutParams lp = new FrameLayout.LayoutParams(FrameLayout.LayoutParams.MATCH_PARENT,FrameLayout.LayoutParams.MATCH_PARENT);
animLayout.setLayoutParams(lp);
animLayout.setBackgroundResource(android.R.color.transparent);
rootView.addView(animLayout);
return animLayout;
}
/**
* @deprecated 将要执行动画的view 添加到动画层
* @param vg
* 动画运行的层这里是frameLayout
* @param view
* 要运行动画的View
* @param location
* 动画的起始位置
* @return
*/
private View addViewToAnimLayout(ViewGroup vg,View view,int[] location){
int x = location[0];
int y = location[1];
vg.addView(view);
FrameLayout.LayoutParams lp = new FrameLayout.LayoutParams(
dip2px(this,90),dip2px(this,90));
lp.leftMargin = x;
lp.topMargin = y;
view.setPadding(5, 5, 5, 5);
view.setLayoutParams(lp);
return view;
}
/**
* dip，dp转化成px 用来处理不同分辨路的屏幕
* @param context
* @param dpValue
* @return
*/
private int dip2px(Context context,float dpValue){
float scale = context.getResources().getDisplayMetrics().density;
return (int)(dpValue*scale +0.5f);
}
/**
* 动画效果设置
* @param drawable
* 将要加入购物车的商品
* @param start_location
* 起始位置
*/
private void setAnim(Drawable drawable,int[] start_location){
Animation mScaleAnimation = new ScaleAnimation(1.5f,0.0f,1.5f,0.0f,Animation.RELATIVE_TO_SELF,0.1f,Animation.RELATIVE_TO_SELF,0.1f);
mScaleAnimation.setDuration(AnimationDuration);
mScaleAnimation.setFillAfter(true);
final ImageView iview = new ImageView(this);
iview.setImageDrawable(drawable);
final View view = addViewToAnimLayout(animation_viewGroup,iview,start_location);
view.setAlpha(0.6f);
int[] end_location = new int[2];
cart_btn.getLocationInWindow(end_location);
int endX = end_location[0];
int endY = end_location[1]-start_location[1];
Animation mTranslateAnimation = new TranslateAnimation(0,endX,0,endY);
Animation mRotateAnimation = new RotateAnimation(0, 180, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
mRotateAnimation.setDuration(AnimationDuration);
mTranslateAnimation.setDuration(AnimationDuration);
AnimationSet mAnimationSet = new AnimationSet(true);
mAnimationSet.setFillAfter(true);
mAnimationSet.addAnimation(mRotateAnimation);
mAnimationSet.addAnimation(mScaleAnimation);
mAnimationSet.addAnimation(mTranslateAnimation);
mAnimationSet.setAnimationListener(new AnimationListener(){
@Override
public void onAnimationStart(Animation animation) {
// TODO Auto-generated method stub
number++;
}
@Override
public void onAnimationEnd(Animation animation) {
// TODO Auto-generated method stub
number–;
if(number==0){
isClean = true;
myHandler.sendEmptyMessage(0);
}
}
@Override
public void onAnimationRepeat(Animation animation) {
// TODO Auto-generated method stub
}
});
view.startAnimation(mAnimationSet);
}
/**
* 内存过低时及时处理动画产生的未处理冗余
*/
@Override
public void onLowMemory() {
// TODO Auto-generated method stub
isClean = true;
try{
animation_viewGroup.removeAllViews();
}catch(Exception e){
e.printStackTrace();
}
isClean = false;
super.onLowMemory();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}

activity_main.xml

<RelativeLayout 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:paddingBottom=“@dimen/activity_vertical_margin”
android:paddingLeft=“@dimen/activity_horizontal_margin”
android:paddingRight=“@dimen/activity_horizontal_margin”
android:paddingTop=“@dimen/activity_vertical_margin”
tools:context=“.MainActivity” >
<ListView
android:layout_width=“match_parent”
android:layout_height=“match_parent”
android:id=“@+id/listview”
></ListView>
<Button
android:layout_alignBottom=“@+id/listview”
android:layout_centerHorizontal=“true”
android:layout_width=“wrap_content”
android:layout_height=“wrap_content”
android:id=“@+id/button”
android:text=“购物车”
/>
</RelativeLayout>

AdapterItem布局

<?xml version=”1.0″ encoding=”utf-8″?>
<RelativeLayout xmlns:android=“http://schemas.android.com/apk/res/android”
android:layout_width=“match_parent”
android:layout_height=“match_parent”
>
<ImageView
android:id=“@+id/item_img”
android:layout_width=“wrap_content”
android:layout_height=“wrap_content”
android:src=“@drawable/ic_launcher”
android:layout_alignParentLeft=“true”
/>
<Button
android:id=“@+id/item_button”
android:layout_width=“wrap_content”
android:layout_height=“wrap_content”
android:layout_alignParentRight=“true”
android:text=“添加”
>
</Button>
</RelativeLayout>

如题，我的 ViewModel 类中有一个列表结构的数据，需要动态加载，代码如下：

class TimelineViewModel : ViewModel() {
    val timelines = MutableLiveData<List<TimelineModel>>(emptyList())

    private var nextTime = System.currentTimeMillis()

    fun getTimeline() {
    	viewModelScope.launch {
            try {
                val respData = Repository.getTimeline(nextTime)
                if (respData.data != null) {
                    nextTime = respData.data.feeds.nextTime
                    val timelineModels = respData.data.feeds.data.filterNotNull().map {
                        TimelineModel(it)
                    }
                    timelines.value = timelines.value.let {
                        if (it == null) {
                            timelineModels
                        } else {
                            it + timelineModels
                        }
                    }
                }
            } catch (e: Exception) {
                Log.e(TAG, "Network Request Fail", e)
            }
        }
    }
}

如果在视图层直接使用 MutableLiveData#observe 方法观察这个数据，那么观察到的是整个 List 数据的变化，那么该怎么将其转化为 Adapter 的添加元素的行为？
或者应该怎么处理这种需要修改列表数据的场景？

nexttime

val

viewmodel

lue

3 条回复 • 2021-08-24 19:57:24 +08:00

omysho 15 天前 via Android 1

有个东西叫 DiffUtil

还有个东西叫 AsyncListDiffer

还有个东西叫 ListAdapter 继承自 Recycler.Adapter 需要一个 ItemDiffCallback 作为构造参数

pigspy 15 天前

@omysho

非常感谢

122006 5 天前

androidx 的 recycleview 自带，直接继承 listadapter 就行

标签： Adapter

android添加购物车动画参考

android添加购物车动画实现

商品列表Adapter

活动类

AdapterItem布局

请教下 ViewModel 和 Adapter 该如何结合以实现动态加载

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