ListView分组实现方案(一)
分组的效果如下表格item列所示：
listView分组思路：在item.xml配置文件里面定义一个显示组名的TextView,该TextView只在当前分组的第一个时显示，其它的默认不显示(即View.GONE);
上面其余列的说明：
position列：对应getView方法里面的position参数；
groupIndex:当然position对应的item属于第几个分组，或者说当前分组的索引号。
group_position:当前分组组名所在的item在listView中所处的位置position，比如分组A在listView中的position位置为0，分组B在listView中对应的position为4
item.xml类似如下效果：
//上下布局的linearLayout <LinearLayout> //用来显示组名比如A <TextView id="group_name"/ > //用来显示item的具体信息比如a1 <TextView id="item_info"/> </LinearLayout>
具体实现思路以及伪代码(getView里面进行处理判断：
1.判断当前position对应的item属于哪一个或者第几个分组；并获取该分组的索引groupIndex
2.根据groupIndex来获取group_position的值，如果group_position==position那么就让group_name对应的textView 显示否则设置为View.GONE;
综上所述整体上getView的伪代码如下：
假设用一个String[] group_names = {"A","B","C",...}来保存分组的名称
int[] group_positions = {0,4}用来保存当前分组在listView中的位置
Int groupIndex = getGroupIndex(position);
Int group_position = getGroup_Position(groupIndex);
If(group_position==position){
group_name.setVisiable(true);
group_name.setText(group_names(groupIndex));
}else{
group_name.setVisiable(false);
}
获取当前item属于哪一个分组getGroupIndex(position)的伪代码如下
//获取当前position 对应的item Item item = getItem(position); //获取groupIndex Int groupIndex = Arrays.binarySearch(group_names,item.getXXX()) return groupIndex>=0? index:-index-2; item.getXXX()是获取item中显示字符串第一个首字母的大写字母 //那么获取当前分组在ListView中对应位置的getGroupPosition(groupIndex)的代码就如下所 return group_positions.get(groupIndex)
关于ListView分组，Android提供了SectionIndexer接口，该接口提供了三个方法，实现分组的思路大体上跟上面讲的差不多，就不在赘述(吐槽，个人感觉SectionIndexer的名字不如GroupIndexer好)
下面贴上自己的测试代码：
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<ListView
android:id="@+id/myListView"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />
</RelativeLayout>item.xml：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<!-- 分组名 -->
<TextView
android:id="@+id/group_name"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="@android:color/darker_gray"/>
<!-- 显示信息 -->
<TextView
android:id="@+id/item_info"
android:layout_width="wrap_content"
android:layout_height="80sp"
android:textSize="45sp" />
</LinearLayout>
public class MainActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ListView list = (ListView) findViewById(R.id.myListView);
ArrayList<String> stringList = InitListData();
MyAdapter adapter = new MyAdapter(this, stringList);
list.setAdapter(adapter);
}
private ArrayList<String> InitListData() {
ArrayList<String> stringList = new ArrayList<String>();
stringList.add("aenegli");
stringList.add("abddaf");
stringList.add("are");
stringList.add("care");
stringList.add("ahow");
stringList.add("abide");
stringList.add("bandidate");
stringList.add("bapture");
stringList.add("catch");
stringList.add("call");
stringList.add("abuse");
stringList.add("cow");
//排个序
Collections.sort(stringList);
return stringList;
}
}
public class MyAdapter extends BaseAdapter {
//分组名
private char groupNames[] = {
'A','B','C'
};
private List<Integer> groupPositions;
private List<String> stringArray;
//初始化groupPositions
private void initGroupPositions(){
groupPositions = new ArrayList<Integer>();
for (int i = 0; i < stringArray.size(); i++) {
if(i==0){//第一条数据
groupPositions.add(0);
continue;
}
if(i != groupPositions.size()){
String currentStr = stringArray.get(i);
String preStr = stringArray.get(i-1);
char firstCharOfCurrentStr = currentStr.charAt(0);
char firstCharOfPreStr = preStr.charAt(0);
if(firstCharOfCurrentStr!=firstCharOfPreStr){
groupPositions.add(i);
}
}
}
}
private Context context;
public MyAdapter(Context context, ArrayList<String> arr) {
stringArray = arr;
this.context = context;
initGroupPositions();
Log.e("groupPositions== ",groupPositions.size()+"");
}
public int getCount() {
return stringArray.size();
}
public String getItem(int position) {
return stringArray.get(position);
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View view, ViewGroup parent) {
LayoutInflater inflate = ((Activity) context).getLayoutInflater();
view = (View) inflate.inflate(R.layout.item, null);
TextView groupNameView = (TextView) view.findViewById(R.id.group_name);
String itemStr = stringArray.get(position);
//分组处理
int groupIndex = getGroupIndex(position);
int groupPosition = getGroupPosition(groupIndex);
if(position==groupPosition){
groupNameView.setText(groupNames[groupIndex]+"");
groupNameView.setVisibility(View.VISIBLE);
}else{
groupNameView.setVisibility(View.GONE);
}
TextView textView = (TextView) view.findViewById(R.id.item_info);
textView.setText(itemStr);
return view;
}
//根据position获取当前item属于第几个group,也就是获取group的索引
public int getGroupIndex(int position) {
String itemStr = getItem(position);
char firstChar = itemStr.toUpperCase().charAt(0);
int groupIndex = Arrays.binarySearch(groupNames, firstChar);
Log.e("firstChar--groupIndex",firstChar+"---"+groupIndex);
return groupIndex>=0?groupIndex:-groupIndex-2;
}
//根据groupIndex来获取当前分组对应于ListView中的position
public int getGroupPosition(int groupIndex){
return groupPositions.get(groupIndex);
}
}