ListView的Item中的图片拖拽功能的实现

最近项目中要用到，所以做了个，刚开始做出来，可能有些地方还没有考虑完整，不过可以拿来参考一下。其实最主要的就是使用了一个自定义的BaseAdapter，在其中的getView方法中，为模板中的图片控件增加了onTouchListener事件即可实现。
运行效果如下：



主布局文件：

1 <?xml version="1.0" encoding="utf-8"?>
2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
3 android:orientation="vertical" android:layout_width="fill_parent"
4 android:layout_height="fill_parent">
5 <ListView android:id="@+id/lvDemo" android:layout_width="fill_parent"
6 android:layout_height="wrap_content" />
7 </LinearLayout>
主布局文件中列表的项模板如下：

1 <?xml version="1.0" encoding="utf-8"?>
2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
3 android:layout_width="fill_parent" android:layout_height="wrap_content"
4 android:orientation="horizontal" android:layout_gravity="center"
5 android:paddingTop="5dp" android:paddingBottom="5dp">
6 <FrameLayout android:id="@+id/flContainer"
7 android:layout_width="fill_parent" android:layout_height="wrap_content">
8 <TextView android:id="@+id/tvShowTitle" android:layout_width="wrap_content"
9 android:layout_height="wrap_content" android:paddingLeft="110dp"
10 android:paddingTop="10dp" android:textSize="16sp">
11 </TextView>
12 <ImageView android:id="@+id/ivLogo" android:layout_width="100dp"
13 android:layout_height="80dp" />
14 <ImageView android:id="@+id/ivAlphaImg"
15 android:layout_width="80dp" android:background="@drawable/pi"
16 android:layout_height="80dp" />
17 </FrameLayout>
18 </LinearLayout>
自定义适配器：

1 package com.studio.basf.animationdemo;
2
3 import java.util.ArrayList;
4 import java.util.HashMap;
5
6 import android.content.Context;
7 import android.util.DisplayMetrics;
8 import android.view.LayoutInflater;
9 import android.view.MotionEvent;
10 import android.view.View;
11 import android.view.View.OnTouchListener;
12 import android.view.ViewGroup;
13 import android.widget.BaseAdapter;
14 import android.widget.ImageView;
15 import android.widget.TextView;
16
17 public class CustomAdapter extends BaseAdapter implements OnTouchListener {
18
19 private LayoutInflater mInflater;
20 private ViewHolder holder;
21 private ArrayList<HashMap<String, String>> list;
22 private int resource, lastX, lastY, vLeft, vTop,vRight, vBottom;
23 private HashMap<String, Object> hashMap;
24 private String[] from;
25 private int[] to;
26 private Context context;
27
28 // 自定义容器类
29 class ViewHolder {
30
31 public ArrayList<ImageView> getIvCollections() {
32 return ivCollections;
33 }
34
35 public void setIvCollections(ArrayList<ImageView> ivCollections) {
36 this.ivCollections = ivCollections;
37 }
38
39 public TextView getTvShowTitle() {
40 return tvShowTitle;
41 }
42
43 public void setTvShowTitle(TextView tvShowTitle) {
44 this.tvShowTitle = tvShowTitle;
45 }
46
47 private ArrayList<ImageView> ivCollections;
48 private TextView tvShowTitle;
49 }
50
51 public CustomAdapter(Context context,
52 ArrayList<HashMap<String, String>> list, int resource,
53 String[] from, int[] to) {
54 this.list = list;
55 this.mInflater = LayoutInflater.from(context);
56 this.resource = resource;
57 this.from = from;
58 this.to = to;
59 this.hashMap = new HashMap<String, Object>();
60 this.context = context;
61 }
62
63 @Override
64 public int getCount() {
65 // TODO Auto-generated method stub
66 return list.size();
67 }
68
69 @Override
70 public Object getItem(int position) {
71 // TODO Auto-generated method stub
72 return list.get(position);
73 }
74
75 @Override
76 public long getItemId(int position) {
77 // TODO Auto-generated method stub
78 return position;
79 }
80
81 @Override
82 public View getView(int position, View convertView, ViewGroup parent) {
83 // TODO Auto-generated method stub
84 if (convertView == null) {
85 holder = new ViewHolder();
86 convertView = mInflater.inflate(resource, null);
87
88 ArrayList<ImageView> ivList = new ArrayList<ImageView>();
89 ivList.add((ImageView) convertView.findViewById(R.id.ivLogo));
90 ivList.add((ImageView) convertView.findViewById(R.id.ivAlphaImg));
91 // 装载ImageView
92 holder.setIvCollections(ivList);
93 // 装载TextView
94 holder.setTvShowTitle((TextView) convertView.findViewById(to[0]));
95
96 convertView.setTag(holder);
97 } else {
98 holder = (ViewHolder) convertView.getTag();
99 }
100
101 // 获取单项数据
102 HashMap<String, String> hashMap = list.get(position);
103
104 holder.getIvCollections().get(0)
105 .setBackgroundResource(R.drawable.anim2);
106 holder.getIvCollections().get(0).setOnTouchListener(this);
107
108 holder.getIvCollections().get(1).getBackground().setAlpha(200);
109 holder.getTvShowTitle().setText(hashMap.get(from[0]));
110
111 return convertView;
112 }
113
114 @Override
115 public boolean onTouch(View v, MotionEvent event) {
116 // TODO Auto-generated method stub
117 switch (event.getAction()) {
118 case MotionEvent.ACTION_DOWN:
119 lastX = (int) event.getRawX();
120 lastY = (int) event.getRawY();
121
122 if (hashMap.isEmpty()) {
123 hashMap.put("l", v.getLeft());
124 hashMap.put("t", v.getTop());
125 hashMap.put("r", GetScreenWidth());
126 hashMap.put("b", v.getBottom());
127 }
128
129 // 获取遮罩层的位置
130 vLeft = Integer.parseInt(hashMap.get("l").toString());
131 vTop = Integer.parseInt(hashMap.get("t").toString());
132 vRight = Integer.parseInt(hashMap.get("r").toString());
133 vBottom = Integer.parseInt(hashMap.get("b").toString());
134
135 break;
136 case MotionEvent.ACTION_MOVE:
137 int dx = (int) event.getRawX() - lastX;
138 int dy = (int) event.getRawY() - lastY;
139
140 int left = v.getLeft() + dx;
141 int top = v.getTop() + dy;
142 int right = v.getRight() + dx;
143 int bottom = v.getBottom() + dy;
144
145 if (left < vLeft) {
146 left = vLeft;
147 right = left + v.getWidth();
148 }
149
150 if (top < vTop) {
151 top = vTop;
152 bottom = top + v.getHeight();
153 }
154
155 if(right > vRight){
156 right = vRight;
157 left = right - v.getWidth();
158 }
159
160 if (bottom > vBottom) {
161 bottom = vBottom;
162 top = bottom - v.getHeight();
163 }
164
165 v.layout(left, top, right, bottom);
166
167 lastX = (int) event.getRawX();
168 lastY = (int) event.getRawY();
169
170 break;
171 case MotionEvent.ACTION_UP:
172 break;
173 }
174 return true;
175 }
176
177 /**
178 * 获取屏幕宽度，将其作为图片拖拽到屏幕最右端时的终止坐标
179 * @return 屏幕宽度
180 */
181 private int GetScreenWidth(){
182 DisplayMetrics dm = context.getResources().getDisplayMetrics();
183 return dm.widthPixels;
184 }
185 }
调用代码如下：

package com.studio.basf.animationdemo;

import java.util.ArrayList;
import java.util.HashMap;

import android.app.Activity;
import android.os.Bundle;
import android.widget.ListView;

public class MainActivity extends Activity {
/** Called when the activity is first created. */
private ArrayList<HashMap<String,String>> list;
private ListView lvDemo;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

list = new ArrayList<HashMap<String,String>>();
lvDemo = (ListView)findViewById(R.id.lvDemo);
addDataTolvDemo();
}

private void addDataTolvDemo() {

HashMap<String,String> hashMap0 = new HashMap<String,String>();
hashMap0.put("title", "不要乱猜哦，我是标题哈~~");
list.add(hashMap0);

HashMap<String,String> hashMap1 = new HashMap<String,String>();
hashMap1.put("title", "不要乱猜哦，我是标题哈~~");
list.add(hashMap1);

HashMap<String,String> hashMap2 = new HashMap<String,String>();
hashMap2.put("title", "不要乱猜哦，我是标题哈~~");
list.add(hashMap2);

HashMap<String,String> hashMap3 = new HashMap<String,String>();
hashMap3.put("title", "不要乱猜哦，我是标题哈~~");
list.add(hashMap3);

HashMap<String,String> hashMap4 = new HashMap<String,String>();
hashMap4.put("title", "不要乱猜哦，我是标题哈~~");
list.add(hashMap4);

CustomAdapter adapter = new CustomAdapter(this, list,
R.layout.main_item, new String[] { "title" },
new int[] { R.id.tvShowTitle });
lvDemo.setAdapter(adapter);
}
}