viewholder_item.xml
1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 android:orientation="vertical" 4 android:layout_width="match_parent" 5 android:layout_height="match_parent"> 6 7 8 9 <ImageView 10 android:id="@+id/iv" 11 android:layout_width="wrap_content" 12 android:layout_height="wrap_content" /> 13 14 <TextView 15 android:id="@+id/tv" 16 android:layout_width="wrap_content" 17 android:layout_height="wrap_content" /> 18 </LinearLayout>
ViewHolderAdapter.java
1 package sowell.oracle.com.listviewholder;
2
3 import android.content.Context;
4 import android.view.LayoutInflater;
5 import android.view.View;
6 import android.view.ViewGroup;
7 import android.widget.BaseAdapter;
8 import android.widget.ImageView;
9 import android.widget.TextView;
10 import android.widget.Toast;
11
12 import java.util.List;
13
14 /**
15 * Created by 94965 on 2017/11/11.
16 */
17
18 public class ViewHolderAdapter extends BaseAdapter {
19
20 private List<String> mData; //储存数据
21 private LayoutInflater mInflater; //实例化布局
22 public Context context;
23
24 public ViewHolderAdapter(Context context,List<String> data){
25 super();
26 this.context=context;
27 this.mData=data;
28 mInflater=LayoutInflater.from(context);
29 }
30
31
32
33 @Override
34 public int getCount() {
35 return mData.size();
36 }
37
38 @Override
39 public Object getItem(int position) {
40 return mData.get(position);
41 }
42
43 @Override
44 public long getItemId(int position) {
45 return position;
46 }
47
48 @Override
49 public View getView(final int position, View convertView, final ViewGroup parent) {
50 ViewHolder holder=null;
51 //判断是否缓存
52 if(convertView==null){
53 holder=new ViewHolder();
54 //通过LayoutInflater实例化布局
55 convertView=mInflater.inflate(R.layout.viewholder_item,null);
56 holder.img=(ImageView)convertView.findViewById(R.id.iv);
57 holder.title=(TextView)convertView.findViewById(R.id.tv);
58 holder.img.setOnClickListener(new View.OnClickListener() {
59 @Override
60 public void onClick(View v) {
61 //对item中的imageview设置点击事件
62 Toast.makeText(context,"第"+(position+1)+"张图片被点击",Toast.LENGTH_SHORT).show();
63 }
64 });
65 convertView.setTag(holder);
66 }else {
67 //通过tag找到缓存‘的布局
68 holder=(ViewHolder)convertView.getTag();
69 }
70
71 //设置布局中控件要显示的视图
72 holder.img.setBackgroundResource(R.mipmap.ic_launcher);
73 holder.title.setText(mData.get(position));
74 return convertView;
75 }
76
77
78
79 public final class ViewHolder{
80 public ImageView img;
81 public TextView title;
82 }
83 }
activity_main.xml
1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 xmlns:tools="http://schemas.android.com/tools" 4 android:layout_width="match_parent" 5 android:layout_height="wrap_content" 6 android:orientation="vertical" 7 tools:context="sowell.oracle.com.listviewholder.MainActivity"> 8 9 10 11 12 <ListView 13 android:id="@+id/lv" 14 android:layout_width="match_parent" 15 android:layout_height="450dp" 16 android:divider="@android:color/darker_gray" 17 android:dividerHeight="1dp" 18 > 19 </ListView> 20 21 22 23 24 <Button 25 android:id="@+id/btn" 26 android:layout_width="match_parent" 27 android:layout_height="wrap_content" 28 android:text="add" /> 29 30 31 <LinearLayout 32 android:layout_width="match_parent" 33 android:layout_height="wrap_content" 34 android:orientation="horizontal" 35 > 36 <EditText 37 android:id="@+id/et" 38 android:layout_weight="1" 39 android:layout_width="wrap_content" 40 android:layout_height="wrap_content" /> 41 <Button 42 android:id="@+id/btn1" 43 android:layout_weight="1" 44 android:onClick="moveto" 45 android:text="移动" 46 android:layout_width="wrap_content" 47 android:layout_height="wrap_content" /> 48 </LinearLayout> 49 50 51 </LinearLayout>
MainActivity.java
1 package sowell.oracle.com.listviewholder;
2
3 import android.support.v7.app.AppCompatActivity;
4 import android.os.Bundle;
5 import android.util.Log;
6 import android.view.MotionEvent;
7 import android.view.View;
8 import android.view.WindowManager;
9 import android.widget.AbsListView;
10 import android.widget.AdapterView;
11 import android.widget.Button;
12 import android.widget.EditText;
13 import android.widget.ListView;
14 import android.widget.Toast;
15
16 import java.util.ArrayList;
17 import java.util.List;
18
19 public class MainActivity extends AppCompatActivity {
20
21 public ListView listView;
22 public ViewHolderAdapter adapter;
23 public List<String> list;
24 public String string;
25 public Button bt;
26 public Button move;
27 private EditText et;
28 public void init(){
29
30 move=(Button)findViewById(R.id.btn1);
31 et=(EditText)findViewById(R.id.et);
32 bt=(Button)findViewById(R.id.btn);
33 bt.setOnClickListener(new View.OnClickListener() {
34 @Override
35 public void onClick(View v) {
36 add();
37 }
38 });
39 list=new ArrayList<String>();
40 for(int i=0;i<=20;i++)
41 {
42 string=""+i;
43 list.add(string);
44 }
45 adapter=new ViewHolderAdapter(this,list);
46 listView=(ListView)findViewById(R.id.lv);
47 listView.setAdapter(adapter);
48 listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
49 @Override
50 public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
51 //对整个item设置点击事件
52 String s=list.get(position);
53 Toast.makeText(MainActivity.this,"第"+(position+1)+"个item被点击",Toast.LENGTH_SHORT).show();
54 }
55 });
56 listView.setOnTouchListener(new View.OnTouchListener() {
57 @Override
58 public boolean onTouch(View v, MotionEvent event) {
59 switch (event.getAction()) {
60 case MotionEvent.ACTION_DOWN:
61 Toast.makeText(MainActivity.this, "ACTION_DOWN", Toast.LENGTH_SHORT).show();
62 break;
63
64 case MotionEvent.ACTION_MOVE:
65 Toast.makeText(MainActivity.this, "ACTION_MOVE", Toast.LENGTH_SHORT).show();
66 break;
67
68 case MotionEvent.ACTION_UP:
69 Toast.makeText(MainActivity.this, "ACTION_UP", Toast.LENGTH_SHORT).show();
70 break;
71 }
72 return false;
73 }
74 });
75
76 listView.setOnScrollListener(new AbsListView.OnScrollListener() {
77 @Override
78 public void onScrollStateChanged(AbsListView view, int scrollState) {
79 switch (scrollState){
80 case AbsListView.OnScrollListener.SCROLL_STATE_IDLE:
81 Toast.makeText(MainActivity.this,"滑动停止",Toast.LENGTH_SHORT).show();
82 break;
83
84 case SCROLL_STATE_TOUCH_SCROLL:
85 Toast.makeText(MainActivity.this,"正在滚动",Toast.LENGTH_SHORT).show();
86 break;
87
88 case SCROLL_STATE_FLING:
89 Toast.makeText(MainActivity.this,"惯性继续滚动",Toast.LENGTH_SHORT).show();
90 break;
91 }
92 }
93
94 @Override
95 public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
96 Toast.makeText(MainActivity.this,""+firstVisibleItem,Toast.LENGTH_SHORT).show();
97 }
98 });
99 }
100
101
102 @Override
103 protected void onCreate(Bundle savedInstanceState) {
104 super.onCreate(savedInstanceState);
105 getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_PAN); //防止被输入框被遮盖
106 setContentView(R.layout.activity_main);
107 init();
108 }
109
110 public void moveto(View view){
111 int position=Integer.parseInt(et.getText().toString());
112 if(position>=0&&position<=list.size()-1)
113 listView.smoothScrollByOffset(position);//平滑移动到布局第一个元素为position
114 //listView.smoothScrollToPosition(position);
115 }
116
117 public void add(){
118 list.add("new");
119 adapter.notifyDataSetChanged(); //动态添加listview中的数据
120 //listView.setSelection(list.size()-1);//瞬间移动
121 listView.smoothScrollToPosition(list.size()-1);//平滑移动到布局中有该位置
122
123 }
124
125
126
127 }
时间： 2024-10-10 15:22:36