android - GridView 项目不向下滚动到向上(重复项目)以及当我从 android 中的服务器加载数据时？

Question

我有一个 GridView ，使用 api 调用在 GridView 中更新数据，网格项目使用 picasso 库从 url 加载图像，所有这些都是完美的，但是当我向下滚动到向上时，网格项目没有滚动并重复项目(向上向下滚动是完美的)。

适配器类.java

private class ProductAdapter extends BaseAdapter {
        ViewHolder holder = null;
        @Override
        public int getCount() {
            return mProducts != null ? mProducts.size() : 0;
        }

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {

        holder = new ViewHolder();
        if (convertView == null) {
          //  convertView = LayoutInflater.from(Products_activity.this).inflate(R.layout.product_layout, null, false);

            LayoutInflater vi = (LayoutInflater)getApplicationContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = vi.inflate(R.layout.product_layout, null);

            holder.product_name = (TextView) convertView.findViewById(R.id.product_name);
            holder.product_descr = (TextView) convertView.findViewById(R.id.product_desc);
            holder.product_price = (TextView) convertView.findViewById(R.id.product_price);
            holder.product_pic = (ImageView) convertView.findViewById(R.id.iv_division_img);
            holder.product_share = (ImageView) convertView.findViewById(R.id.productshare_button);
            holder.like_image=(ImageView) convertView.findViewById(R.id.like_image);
            convertView.setTag(holder);
        }else{
            holder = (ViewHolder)convertView.getTag();
        }





        if (mProducts != null) {
            String url = "http://staggershop.pivalue.net/assets/product_images/"+mProducts.get(position).product_image;
            String urls = url.replaceAll(" ", "%20");
            Picasso.with(getApplicationContext()).load(urls).resize(300,300).noFade().error(R.drawable.home_brands).into(holder.product_pic);
            holder.product_name.setText(mProducts.get(position).product_name);
            //product_descr.setText(mProducts.get(position).pr);
            // product_price.setText(mProducts.get(position).product_price);
           /* Picasso
                    .with(getApplicationContext())
                    .setLoggingEnabled(true);

            Picasso.with(getApplicationContext())
                    .load(urls)
                    .error(R.drawable.home_brands).memoryPolicy(MemoryPolicy.NO_STORE)
                    .networkPolicy(NetworkPolicy.NO_STORE)
                    .into(product_pic);*/
            holder.product_descr.setText(mProducts.get(position).product_description);

            if(!recently_beans.isEmpty()){
                for(int i=0;i<recently_beans.size();i++) {
                    if (mProducts.get(position).prdid.equals(recently_beans.get(i).prod_id))
                    {
                        holder.like_image.setImageResource(R.drawable.like);

                    }
                }

                     notifyDataSetChanged();


            }






        }

        holder.product_share.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                BottomSheetFragment bottomSheetFragment = new BottomSheetFragment();
                bottomSheetFragment.show(getSupportFragmentManager(), bottomSheetFragment.getTag());
            }
        });
        holder.like_image.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                    new Handler(Looper.getMainLooper()).post(new Runnable() {
                        public void run() {
                            if (!recently_beans.isEmpty()) {

                                for (int i = 0; i < recently_beans.size(); i++) {
                                    if (mProducts.get(position).prdid.equals(recently_beans.get(i).prod_id)) {

                                        holder.like_image.setImageResource(R.drawable.dislike);
                                        Inserfavorite(mProducts.get(position).prdid);


                                    }
                                }


                            }
                        }
                    });

                }

            });

           // notifyDataSetChanged();
        convertView.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                Inserrecent(mProducts.get(position).prdid);
                Intent intent = new Intent(Products_activity.this, Product_description.class);

                startActivity(intent);


            }
        });
        return convertView;
    }

}
public static class ViewHolder {
    public TextView product_name;
    public TextView product_descr;
    public TextView product_price;
    public ImageView product_pic ;
    public ImageView product_share;
    public ImageView like_image;

这是我的 product.xml

 <RelativeLayout
        android:id="@+id/rl_divisioin_image"
        android:layout_width="match_parent"
        android:layout_height="200dp"
        android:layout_centerHorizontal="true">
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">

     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="0dp"
         android:layout_weight="1"
         android:id="@+id/product_img">


         <ImageView
             android:id="@+id/iv_division_img"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:layout_below="@+id/view"
             android:adjustViewBounds="true"
             android:layout_centerHorizontal="true"
             android:scaleType="fitXY"
             android:src="@drawable/home_brands" />
     </LinearLayout>

            <LinearLayout
                android:id="@+id/prod_name_layout"
                android:layout_width="match_parent"
                android:layout_height="0dp"
                android:layout_below="@+id/product_img"
                android:layout_weight="1"
                android:orientation="vertical">
                <TextView
                    android:id="@+id/product_name"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center"
                    android:elevation="4dp"
                    android:fontFamily="@string/font_family_regular"
                    android:gravity="center"
                  android:padding="5dp"
                    android:maxLines="1"
                    android:text="product name"
                    android:textColor="@color/black"
                    android:textSize="10sp" />
                <TextView
                    android:id="@+id/product_desc"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center"
                    android:elevation="4dp"
                    android:fontFamily="@string/font_family_regular"
                    android:gravity="center"
                    android:maxLines="1"
                    android:padding="5dp"
                    android:text="product Description"
                    android:textColor="@color/black"
                    android:textSize="10sp" />
                <RelativeLayout
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_below="@+id/product_desc"
                    android:layout_gravity="center"
                    android:layout_marginTop="20dp">
                    <TextView
                        android:id="@+id/product_price"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_alignParentStart="true"
                        android:layout_alignParentTop="true"
                        android:elevation="4dp"
                        android:text="100$"
                        android:textColor="@color/black"
                        android:textSize="12sp"
                        android:textStyle="bold" />
                    <ImageView
                        android:id="@+id/productshare_button"
                        android:layout_width="20dp"
                        android:layout_height="20dp"
                        android:layout_alignParentEnd="true"
                        android:elevation="4dp"
                        android:layout_marginRight="5dp"
                        android:src="@mipmap/symbol_dotss"
                        android:text="product name"
                        android:textColor="@color/black"
                        android:textSize="10sp" />
                </RelativeLayout>
            </LinearLayout>
        </LinearLayout>
        <ImageView
            android:layout_width="25dp"
            android:layout_height="25dp"
android:layout_margin="5dp"
            android:id="@+id/like_image"
            android:layout_alignParentEnd="true"
            android:src="@drawable/dislike" />
    </RelativeLayout>

activty_product.xml

<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/coordinator"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <RelativeLayout
        android:id="@+id/rltool"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">


        <android.support.v7.widget.Toolbar
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/toolbar1"
            android:background="@color/textColorPrimary"

            app:titleTextColor="@color/colorPrimary"
            android:minHeight="?attr/actionBarSize"

            app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
            app:theme="@style/AppTheme.Toolbar"
            app:layout_scrollFlags="scroll|enterAlways">
            <LinearLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/search1"
                android:layout_alignParentRight="true"
                android:layout_alignParentEnd="true"

                android:background="@drawable/background_shape_buttons">



                <!-- <EditText
                     android:id="@+id/searchEditText"
                     android:layout_width="match_parent"
                     android:layout_height="wrap_content"
                     android:textColorHint="#D6D5C0"
                     android:hint="Search..................."
                     android:layout_gravity="center"
                     android:backgroundTint="#00000000" />-->
                <SearchView
                    android:id="@+id/search"
                    android:layout_width="200dp"
                    android:layout_height="wrap_content"
                    android:textColorHint="#D6D5C0"

                    android:text="@string/search"
                    android:layout_gravity="center"
                    android:iconifiedByDefault="false">

                    <requestFocus />
                </SearchView>

            </LinearLayout>
        </android.support.v7.widget.Toolbar>

        <View
            android:id="@+id/shadow_view"
            android:layout_width="match_parent"
            android:layout_alignBottom="@+id/toolbar1"
            android:visibility="visible"
            android:layout_height="3dp"
            android:background="@drawable/toolbar_shadow" />
</RelativeLayout>
   <GridView
        android:id="@+id/product_list"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:scrollbars="vertical"

       android:layout_margin="15dp"
        android:horizontalSpacing="10dp"
        android:numColumns="2"

        android:verticalSpacing="10dp">


    </GridView>
</LinearLayout>
</android.support.design.widget.CoordinatorLayout>

Answer 1

为避免意外行为，提供

的实现

@Override
public Object getItem(int position) {
    return mProducts.get(position);
}

@Override
public long getItemId(int position) {
    //return position; or better to provide some unique id 
    // as there is one in your code, product id
    return mProducts.get(position).prod_id;
}

注意:删除 getView 中的 notifyDataSetChanged(); 因为它会触发适配器刷新所有正在创建的 View ，这可能会导致此行为。

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