需要引入的包有：

import android.content.Context; import android.view.View; import android.view.ViewGroup; import android.widget.Adapter; import android.widget.ArrayAdapter; import android.widget.BaseAdapter;import java.util.LinkedHashMap; import java.util.Map;以下開始類的構建：

public class SeparatedListAdapter extends BaseAdapter {public final Map<String, Adapter> sections = new LinkedHashMap<>();public final ArrayAdapter<String> headers;public final static int TYPE_SECTION_HEADER = 0；首先，聲明一個終態的Map<String, Adapter>型變量sections，鍵值對的類型實參為String和Adapter，且創建一個新的LinkedHashMap()型的變量，賦給變量sections。和一個ArrayAdapter型的變量headers，且類型實參為String。LinkedHashMap 是 Map 的實現類，Map是一個公有接口，LinkedHashMap等一系列Map是公有類，繼承于HashMap，調用Map接口。

public SeparatedListAdapter(Context context) {headers = new ArrayAdapter<String>(context, R.layout.list_header);}public void addSection(String section, Adapter adapter) {this.headers.add(section);this.sections.put(section, adapter);}

接著，將addSection方法中傳入的參數分別寫入headers和sections中。

其中，headers類型為ArrayAdapter，sections類型為LinkedHashMap，結構分別為：ArrayAdapter(Context, int)和LinkedHashMap(int, float), add(sections)表示將section插入隊列headers隊尾，put(section, adapter)表示將字符串section置于adapter鍵位。

public Object getItem(int position) {for (Object section : this.sections.keySet()) {Adapter adapter = sections.get(section);int size = adapter.getCount() + 1;// check if position inside this sectionif (position == 0)return section;if (position < size)return adapter.getItem(position - 1);// otherwise jump into next sectionposition -= size;}return null;}

獲取Item方法，在sections.keySet()中遍歷keys，（其中keySet()返回全部的keys）將adapter的數量賦給size，如果Item的位置參數為0，則返回第一個，否則，倒敘遍歷查找

public int getCount() {// total together all sections, plus one for each section headerint total = 0;for (Adapter adapter : this.sections.values())total += adapter.getCount() + 1;return total;}遞歸得到sections數量

public int getViewTypeCount() {// assume that headers count as one, then total all sectionsint total = 1;for (Adapter adapter : this.sections.values())total += adapter.getViewTypeCount();return total;}返回adapter的types of view 的數量

public int getItemViewType(int position) {int type = 1;for (Object section : this.sections.keySet()) {Adapter adapter = sections.get(section);int size = adapter.getCount() + 1;// check if position inside this sectionif (position == 0)return TYPE_SECTION_HEADER;if (position < size)return type + adapter.getItemViewType(position - 1);// otherwise jump into next sectionposition -= size;type += adapter.getViewTypeCount();}return -1;}遞歸得到position位置的viewtype

public boolean isEnabled(int position) {return (getItemViewType(position) != TYPE_SECTION_HEADER);}public View getView(int position, View convertView, ViewGroup parent) {int sectionnum = 0;for (Object section : this.sections.keySet()) {Adapter adapter = sections.get(section);int size = adapter.getCount() + 1;// check if position inside this sectionif (position == 0)return headers.getView(sectionnum, convertView, parent);if (position < size)return adapter.getView(position - 1, convertView, parent);// otherwise jump into next sectionposition -= size;sectionnum++;}return null;}public long getItemId(int position) {return position;}

總結

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