Android~Adapter(BaseAdapter+ListView)demo Dear 丶 2022-10-18 00:55 197阅读 0赞 一、BaseAdapter+ListView 1、思维导图 ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ5NTY3OA_size_16_color_FFFFFF_t_70] 2、详细代码 (1)listview\_item.xml <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="horizontal"> <ImageView android:id="@+id/fruitImg" android:layout_width="60dp" android:layout_height="60dp" android:src="@drawable/strawberry" /> <LinearLayout android:layout_width="wrap_content" android:layout_height="60dp" android:gravity="center_vertical" android:orientation="vertical"> <TextView android:id="@+id/fruitName" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="草莓" android:textSize="18sp" /> <TextView android:id="@+id/fruitPrice" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="15元/KG" android:textSize="15sp" /> </LinearLayout> </LinearLayout> (2)ListViewAdapter public class ListViewAdapter extends BaseAdapter { private List<Fruit> mList; private Context mContext; private ViewHolder viewHolder; public ListViewAdapter(List<Fruit> mList, Context mContext) { this.mList = mList; this.mContext = mContext; } @Override public int getCount() { return mList.size(); } @Override public Object getItem(int position) { return mList.get(position); } @Override public long getItemId(int position) { return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { viewHolder = new ViewHolder(); if (convertView == null) { convertView = LayoutInflater.from(mContext).inflate(R.layout.listview_item, parent, false); viewHolder.imageView = convertView.findViewById(R.id.fruitImg); viewHolder.textName = convertView.findViewById(R.id.fruitName); viewHolder.textPrice = convertView.findViewById(R.id.fruitPrice); // 缓存各个控件的实例 convertView.setTag(viewHolder); } else { // 取出缓存 viewHolder = (ViewHolder) convertView.getTag(); } viewHolder.imageView.setImageResource(mList.get(position).getImage()); viewHolder.textName.setText(mList.get(position).getName()); viewHolder.textPrice.setText(mList.get(position).getPrice()); return convertView; } // 内部类 static class ViewHolder { ImageView imageView; TextView textName; TextView textPrice; } } (3)fragment\_home.xml <ListView android:id="@+id/listView" android:layout_width="match_parent" android:layout_height="match_parent" /> (4)HomeFragment 类 public class HomeFragment extends Fragment { private ListView listView; private ListViewAdapter adapter; private List<Fruit> mList; @Nullable @Override public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.fragment_home, container, false); listView = view.findViewById(R.id.listView); initFruit(); adapter = new ListViewAdapter(mList, getContext()); listView.setAdapter(adapter); return view; } private void initFruit() { mList = new ArrayList<Fruit>(); mList.add(new Fruit(R.drawable.strawberry, "草莓", "15元/KG")); mList.add(new Fruit(R.drawable.cherry, "樱桃", "18元/KG")); mList.add(new Fruit(R.drawable.watermelon, "西瓜", "6元/KG")); mList.add(new Fruit(R.drawable.apple, "苹果", "10元/KG")); mList.add(new Fruit(R.drawable.litchi, "荔枝", "9.9元/KG")); mList.add(new Fruit(R.drawable.strawberry, "草莓", "15元/KG")); mList.add(new Fruit(R.drawable.cherry, "樱桃", "18元/KG")); mList.add(new Fruit(R.drawable.watermelon, "西瓜", "6元/KG")); mList.add(new Fruit(R.drawable.apple, "苹果", "10元/KG")); mList.add(new Fruit(R.drawable.litchi, "荔枝", "9.9元/KG")); mList.add(new Fruit(R.drawable.strawberry, "草莓", "15元/KG")); mList.add(new Fruit(R.drawable.cherry, "樱桃", "18元/KG")); mList.add(new Fruit(R.drawable.watermelon, "西瓜", "6元/KG")); mList.add(new Fruit(R.drawable.apple, "苹果", "10元/KG")); mList.add(new Fruit(R.drawable.litchi, "荔枝", "9.9元/KG")); } } 运行效果,如下图所示: ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ5NTY3OA_size_16_color_FFFFFF_t_70 1] 二、ListView加载不同布局 通过getItemViewType()方法,根据不同类型,加载不同的布局,不同布局的加载顺序由具体业务逻辑决定,结合上面1。 1、思维导图 ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ5NTY3OA_size_16_color_FFFFFF_t_70 2] 2、详细代码 (1)ListViewAdapter public class ListViewAdapter extends BaseAdapter { private List<Fruit> mList; private Context mContext; private ViewHolder viewHolder; private ViewHolderSe viewHolderSe; private LayoutInflater inflater; private static final int type_1 = 0; private static final int type_2 = 1; public ListViewAdapter(List<Fruit> mList, Context mContext) { this.mList = mList; this.mContext = mContext; } @Override public int getCount() { return mList.size(); } @Override public Object getItem(int position) { return mList.get(position); } @Override public long getItemId(int position) { return position; } @Override public int getViewTypeCount() { return 2; } @Override public int getItemViewType(int position) { int type = position % 5; if (type < 4) { return type_1; } else { return type_2; } // return position % 2; } @Override public View getView(int position, View convertView, ViewGroup parent) { int type = getItemViewType(position); viewHolder = new ViewHolder(); viewHolderSe = new ViewHolderSe(); inflater = LayoutInflater.from(mContext); if (convertView == null) { switch (type) { case type_1: convertView = inflater.inflate(R.layout.listview_item, parent, false); viewHolder.imageView = convertView.findViewById(R.id.fruitImg); viewHolder.textName = convertView.findViewById(R.id.fruitName); viewHolder.textPrice = convertView.findViewById(R.id.fruitPrice); // 缓存各个控件的实例 convertView.setTag(viewHolder); break; case type_2: convertView = inflater.inflate(R.layout.other_listview_item, parent, false); viewHolderSe.imageViewSe = convertView.findViewById(R.id.oFruitImg); viewHolderSe.textDetails = convertView.findViewById(R.id.oFruitDetails); // 缓存各个控件的实例 convertView.setTag(viewHolderSe); break; default: break; } } else { // 取出缓存 switch (type) { case type_1: viewHolder = (ViewHolder) convertView.getTag(); break; case type_2: viewHolderSe = (ViewHolderSe) convertView.getTag(); break; default: break; } } switch (type) { case type_1: viewHolder.imageView.setImageResource(mList.get(position).getImage()); viewHolder.textName.setText(mList.get(position).getName()); viewHolder.textPrice.setText(mList.get(position).getPrice()); break; case type_2: viewHolderSe.imageViewSe.setImageResource(mList.get(position).getImage()); viewHolderSe.textDetails.setText("\t\t\t\t" + mList.get(position).getDetails()); break; default: break; } return convertView; } // 内部类 static class ViewHolder { ImageView imageView; TextView textName; TextView textPrice; } static class ViewHolderSe { ImageView imageViewSe; TextView textDetails; } } 运行效果,如下图所示: ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ5NTY3OA_size_16_color_FFFFFF_t_70 3] [watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ5NTY3OA_size_16_color_FFFFFF_t_70]: /images/20221014/1a76c7270ba64560bf4661543b51fdfe.png [watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ5NTY3OA_size_16_color_FFFFFF_t_70 1]: /images/20221014/00ccc5a7a1cd49d3990d58bac4b36bef.png [watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ5NTY3OA_size_16_color_FFFFFF_t_70 2]: /images/20221014/a28091bd6db14462928903ba73679984.png [watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ5NTY3OA_size_16_color_FFFFFF_t_70 3]: /images/20221014/6896ab88fe9542a5a0727f0dc234c42d.png
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