1.ListView的基本使用
作用：android系统中显示列表的控件
2.两种适配器(ArrayAdapter、simpleAdapter)
数据适配器 是连接数据源和视图界面的桥梁
作用：把复杂的数据(数组、链表、数据库、集合等)填充到指定视图界面上
ArrayAdapter:用于绑定格式单一数据
数据源：集合或者数组
SimpleAdapter:用于绑定格式复杂的数据
数据源：只能是特定泛型的集合
实现过程：新建适配器->添加数据源到适配器->视图加载适配器
使用ArrayAdapter：
package com.drumbass.listviewtest;
import android.app.Activity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class MainActivity1 extends Activity {
private ListView listView;
private ArrayAdapter<String> mArrayAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView) findViewById(R.id.listView1);
String mdata[] = { "DrumBass1", "DrumBass2", "DrumBass3", "DrumBass4",
"DrumBass5" };
mArrayAdapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, mdata);
listView.setAdapter(mArrayAdapter);
}
}
使用simpleAdapter：
1 package com.drumbass.listviewtest;
2
3 import java.util.ArrayList;
4 import java.util.HashMap;
5 import java.util.List;
6 import java.util.Map;
7
8 import android.app.Activity;
9 import android.os.Bundle;
10 import android.widget.ListView;
11 import android.widget.SimpleAdapter;
12
13 public class MainActivity2 extends Activity {
14 private ListView listView;
15 private SimpleAdapter mSimpleAdapter;
16 private List<Map<String, Object>> mDataList;
17
18 @Override
19 protected void onCreate(Bundle savedInstanceState) {
20 super.onCreate(savedInstanceState);
21 setContentView(R.layout.activity_main);
22 listView = (ListView) findViewById(R.id.listView1);
23 mDataList = new ArrayList<Map<String, Object>>();
24 mSimpleAdapter = new SimpleAdapter(this, getData(), R.layout.item,
25 new String[] { "pic", "text" },
26 new int[] { R.id.pic, R.id.text });
27 listView.setAdapter(mSimpleAdapter);
28 }
29 private List<Map<String, Object>> getData(){
30 for (int i = 0; i < 20; i++) {
31 Map<String,Object> map = new HashMap<String,Object>();
32 map.put("pic", R.drawable.ic_launcher);
33 map.put("text", "DrumBass"+i);
34 mDataList.add(map);
35 }
36 return mDataList;
37 }
38
39 }
自定义xml文件：item.xml
1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout 3 xmlns:android="http://schemas.android.com/apk/res/android" 4 android:layout_width="match_parent" 5 android:layout_height="match_parent" 6 android:orientation="horizontal" > 7 <ImageView 8 android:layout_height="wrap_content" 9 android:layout_width="wrap_content" 10 android:src="@drawable/ic_launcher" 11 android:id="@+id/pic" 12 /> 13 <TextView 14 android:id="@+id/text" 15 android:layout_width="wrap_content" 16 android:layout_height="wrap_content" 17 android:text="DrumBass" 18 android:gravity="center" 19 /> 20 21 </LinearLayout>
运行结果：
3.两种监听器(OnScrollingListener、OnItemClickListener)
4.适配器数据刷新(notifyDataChanged)
1 package com.drumbass.listviewtest;
2
3 import java.util.ArrayList;
4 import java.util.HashMap;
5 import java.util.List;
6 import java.util.Map;
7
8 import android.app.Activity;
9 import android.os.Bundle;
10 import android.util.Log;
11 import android.view.View;
12 import android.widget.AbsListView;
13 import android.widget.AbsListView.OnScrollListener;
14 import android.widget.AdapterView;
15 import android.widget.AdapterView.OnItemClickListener;
16 import android.widget.ListView;
17 import android.widget.SimpleAdapter;
18 import android.widget.Toast;
19
20 public class MainActivity2 extends Activity implements OnItemClickListener,
21 OnScrollListener {
22 private ListView listView;
23 private SimpleAdapter mSimpleAdapter;
24 private List<Map<String, Object>> mDataList;
25
26 @Override
27 protected void onCreate(Bundle savedInstanceState) {
28 super.onCreate(savedInstanceState);
29 setContentView(R.layout.activity_main);
30 listView = (ListView) findViewById(R.id.listView1);
31 mDataList = new ArrayList<Map<String, Object>>();
32 mSimpleAdapter = new SimpleAdapter(this, getData(), R.layout.item,
33 new String[] { "pic", "text" },
34 new int[] { R.id.pic, R.id.text });
35 listView.setAdapter(mSimpleAdapter);
36 listView.setOnItemClickListener(this);
37 listView.setOnScrollListener(this);
38 }
39
40 private List<Map<String, Object>> getData() {
41 for (int i = 0; i < 20; i++) {
42 Map<String, Object> map = new HashMap<String, Object>();
43 map.put("pic", R.drawable.ic_launcher);
44 map.put("text", "DrumBass" + i);
45 mDataList.add(map);
46 }
47 return mDataList;
48 }
49
50 @Override
51 public void onScrollStateChanged(AbsListView view, int scrollState) {
52 switch (scrollState) {
53 case SCROLL_STATE_FLING:
54 Log.i("Main", "用户在手指离开之前，用力滑动，视图还在滚动");
55 Map<String, Object> map = new HashMap<String, Object>();
56 map.put("pic", R.drawable.ic_launcher);
57 map.put("text", "TR");
58 mDataList.add(map);
59 mSimpleAdapter.notifyDataSetChanged();
60 break;
61 case SCROLL_STATE_IDLE:
62 Log.i("Main", "视图停止滑动");
63 break;
64 case SCROLL_STATE_TOUCH_SCROLL:
65 Log.i("Main", "视图在滚动");
66 break;
67 }
68 }
69
70 @Override
71 public void onScroll(AbsListView view, int firstVisibleItem,
72 int visibleItemCount, int totalItemCount) {
73
74 }
75
76 @Override
77 public void onItemClick(AdapterView<?> parent, View view, int position,
78 long id) {
79 String text = listView.getItemAtPosition(position) + "";
80 Toast.makeText(this, "position" + position + "text" + text,
81 Toast.LENGTH_SHORT).show();
82 }
83
84 }
终于写完了，虽然都只是笔记，但是花了很多时间。也许是我的学习方法错了？ 是不是应该学完后练练再来写？ 那样也许效率会高很多，下次试试。
时间： 2024-08-07 16:59:06