安卓開發-ListView的介面卡和監聽器/ExpandableListView的使用
阿新 • • 發佈：2019-01-04
《一：BaseAdapter的簡單使用》
1.定義類MyAdapter,繼承BaseAdapter:
public class MyAdapter extends BaseAdapter {
//將佈局檔案轉換成View物件
private LayoutInflater mLayoutInflater;
//ListView中的值
private List<String> mDatas;
//在構造器中將值傳進並初始化成員變數
public MyAdapter(Context c) {
mLayoutInflater = LayoutInflater.from(c);
}
//告訴ListView預設顯示幾條資料 2.在MainActivity中呼叫MyAdapter：
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//1.獲取ListView控制元件
ListView listView = (ListView)findViewById(R.id.lv);
//2.給列表ListView設定值
List<String> datas = new ArrayList<>();
for (int i = 0; i < 100; i++) {
datas.add("介面" + i);
}
//3.傳入Context物件建立介面卡物件，並與ListView繫結
MyAdapter adapter = new MyAdapter(this);
listView.setAdapter(adapter);
//4.將資料傳到介面卡中：
adapter.setDatas(datas);
//5.資料一般是從伺服器傳送而來，有延遲現象，呼叫此方法會執行getCount,getView
adapter.notifyDataSetChanged();
}
}
《二：ArrayAdapter》
ListView listView = (ListView)findViewById(R.id.lv);
ArrayAdapter<String> adpater = new ArrayAdapter(this, android.R.layout.simple_list_item_1, android.R.id.text1,datas);
listView.setAdapter(adapter);《三：SimpleAdapter》
1.在MainActivity中：
ListView listView = (ListView) findViewById(R.id.lv);
List<Map<String, Object>> datas = new ArrayList<>();
for (int i = 1; i <= 7; i++) {
Map<String, Object> dataMap = new HashMap<>();
datas.add(dataMap);
dataMap.put("pic", R.drawable.a1);
dataMap.put("textView", "文字" + i);
}
SimpleAdapter simpleAdapter = new SimpleAdapter(this, datas,
R.layout.simpleadapter_item_layout, new String[] { "pic",
"textView" }, new int[]{ R.id.iv, R.id.tv });
listView.setAdapter(simpleAdapter);2.simpleadapter_item_layout.xml中：
<?xml version="1.0" encoding="utf-8"?>"E:/java/OpenSource/code/AndroidApp/SimpleAdapter/res/layout/activity_main.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/iv"
android:layout_width="40dp"
android:layout_height="40dp"
android:layout_gravity="center_vertical" />
<TextView
android:id="@+id/tv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#F00"
android:layout_margin="20dp" />
</LinearLayout>
《四：ListView的監聽器》
1.滑動監聽器：
ListView.setOnScrollListener(new OnScrollListener(){
//1.滑動狀態改變時呼叫：
//OnScrollListener.SCROLL_STATE_FLING : 慣性滑動
//OnScrollListener.SCROLL_STATE_IDLE : 不動
//OnScrollListener.SCROLL_STATE_TOUCH_SCROLL:拖拽滑動
public void onScrollStateChanged(AbsListView view, int scrollState){
}
//2.列表滑動就會呼叫此函式：列表顯示第一項，可見幾項，總共項數
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount){
}2.點選監聽器：
//1.在MyAdapter中：
public Object getItem(int position){
return mDatas != null ? mDatas.get(position) : null);
}
//2.在MainActivity中：
ListView.setOnItemClickListener(new OnItemClickListener(){
public void onItemClick(AdapterView<?> parent, View view, int position, long id){
String item = （String)adapter.getItem(position);
}
});《五：ExpandableListView》
1.建立介面卡類：
public class MyAdapter extends BaseExpandableListAdapter {
private LayoutInflater mInflater;
private List<String> mGroupNames;
private Map<String, List<String>> mChildNames;
public MyAdapter(Context c, List<String> groupNames, Map<String, List<String>> childNames){
mInflater = LayoutInflater.from(c);
mGroupNames = groupNames;
mChildNames = childNames;
}
public int getGroupCount() {
return mGroupNames.size();
}
public int getChildrenCount(int groupPosition) {
return mChildNames.size();
}
public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
TextView view = null;
if(convertView == null){
convertView = mInflater.inflate(android.R.layout.simple_list_item_1, null);
view = (TextView)convertView.findViewById(android.R.id.text1);
convertView.setTag(view);
}else{
view = (TextView)convertView.getTag();
}
view.setText(mGroupNames.get(groupPosition));
return convertView;
}
public View getChildView(int groupPosition, int childPosition,
boolean isLastChild, View convertView, ViewGroup parent) {
TextView view = null;
if(convertView == null){
convertView = mInflater.inflate(android.R.layout.simple_list_item_1, null);
view = (TextView)convertView.findViewById(android.R.id.text1);
convertView.setTag(view);
}else{
view = (TextView)convertView.getTag();
}
String groupName = mGroupNames.get(groupPosition);
List<String> childNames = mChildNames.get(groupName);
view.setText(childNames.get(childPosition));
return convertView;
}
public Object getGroup(int groupPosition) {
return null;
}
public Object getChild(int groupPosition, int childPosition) {
return null;
}
public long getGroupId(int groupPosition) {
return 0;
}
public long getChildId(int groupPosition, int childPosition) {
return 0;
}
public boolean hasStableIds() {
return false;
}
public boolean isChildSelectable(int groupPosition, int childPosition) {
return false;
}
}
2.在MainActivity中：
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//1.得ExpandableListView物件
ExpandableListView expandableListView = (ExpandableListView)findViewById(R.id.ev);
//2.建立每組的名字集合
List<String> groupNames = new ArrayList<>();
//3.建立每組的中的資料map
Map<String,List<String>> childNames = new HashMap<>();
for (int i = 0; i < 4; i++) {
groupNames.add("Group" + i);
}
for (int i = 0; i < groupNames.size(); i++) {
String groupName = groupNames.get(i);
List<String> childs = new ArrayList<>();
for (int j = 0; j < 4; j++) {
childs.add("Child" + j);
}
childNames.put(groupName, childs);
}
//4.建立介面卡，並繫結資料
MyAdapter adapter = new MyAdapter(this, groupNames, childNames);
//5.將列表與介面卡繫結
expandableListView.setAdapter(adapter);
}
}