Android自定义通用适配器

BaseAdapter：getCount() getItem() getItemId() 基本都是固定的写法，每次都这样写，所以我们可以将他们写到父类中固定下来，以后不必再写；getView()中两种优化的方法和流程是固定的，我们也可以把这些优化的代码固定下来，只留下需要每次修改的部分让子类实现即可。 

根据以往我们写过的适配器： 

每次编写Adapter会变化的部分：1.ViewHolder装载具体的控件。2.加载数据。 

1. 通用适配器MyBaseAdapter.java

package com.example.zhaoxin.commonbaseadapter.adapter;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;

import java.util.List;

/**
* Created by zhaoxin on 17/11/23.
* 自定义通用适配器
*/

public abstract class MyBaseAdapter<T, E extends MyBaseAdapter.ViewHolder> extends BaseAdapter{
// 数据
private List<T> entityList;
// 界面
private int resourceId;
// 上下文
private Context context;

public MyBaseAdapter(Context context, int resourceId, List<T> entityList){
this.context = context;
this.resourceId = resourceId;
this.entityList = entityList;
}

@Override
public int getCount() {
return entityList.size();
}

@Override
public Object getItem(int position) {
return entityList.get(position);
}

@Override
public long getItemId(int position) {
return position;
}

@Override
public View getView(int position, View view, ViewGroup viewGroup) {
if (null == view){
// 新建视图
view = LayoutInflater.from(context).inflate(resourceId, null);
// 完成ViewHolder
E holder = createViewHolder(view);
// 保存ViewHolder
view.setTag(holder);
}
// 获取ViewHolder
E holder = (E)view.getTag();
// 获取数据
T entity = (T) getItem(position);
// 绑定数据
bindDataAndView(holder, entity);
return view;
}

/**
* 创建ViewHolder
* @param convertView
* @return 自己定义的ViewHolder
*/
public abstract E createViewHolder(View convertView);

/**
* 绑定数据到界面
* @param holder 自定义的viewHolder
* @param data
*/
public abstract void bindDataAndView(E holder, T data);

/**
* 子类viewholder必须继承
*/
public static abstract class ViewHolder{

}
}

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
自定义适配器继承通用适配器MyListViewAdapter.java

package com.example.zhaoxin.commonbaseadapter.adapter;

import android.content.Context;
import android.view.View;
import android.widget.TextView;

import com.example.zhaoxin.commonbaseadapter.R;
import com.example.zhaoxin.commonbaseadapter.entity.Book;

import java.util.List;

/**
* Created by zhaoxin on 17/11/23.
* ListView适配器
*/

public class MyListViewAdapter extends MyBaseAdapter<Book, MyListViewAdapter.BookViewHolder> {

public MyListViewAdapter(Context context, int resourceId, List<Book> bookList) {
super(context, resourceId, bookList);
}

@Override
public BookViewHolder createViewHolder(View convertView) {
BookViewHolder holder = new BookViewHolder();
// 获取视图
holder.tv_book_name = convertView.findViewById(R.id.tv_book_name);
holder.tv_book_price = convertView.findViewById(R.id.tv_book_price);
return holder;
}

@Override
public void bindDataAndView(BookViewHolder holder, Book data) {
// 为列表项设置数据
holder.tv_book_name.setText(data.getBookName());
holder.tv_book_price.setText(data.getBookPrice());
}

class BookViewHolder extends MyBaseAdapter.ViewHolder{
// View
TextView tv_book_name;
TextView tv_book_price;
}
}

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
MainActivity.java
宁波最好的整形医院http://www.lyxcl.org/

宁波好的整形医院http://www.lyxcl.org/

package com.example.zhaoxin.commonbaseadapter;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.ListView;

import com.example.zhaoxin.commonbaseadapter.adapter.MyListViewAdapter;
import com.example.zhaoxin.commonbaseadapter.entity.Book;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

private ListView listView;// View
private List<Book> bookList;// 图书集合

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

// 获取listView组件
listView = (ListView) findViewById(R.id.list);
// 获取图书集合对象
bookList = new ArrayList<>();
// 循环添加集合数据
for (int i = 0; i < 10; i++) {
Book book = new Book("Android", "45");
bookList.add(book);
}
// 为组件设置适配器展示数据
listView.setAdapter(new MyListViewAdapter(this, R.layout.item_list, bookList));
}
}

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
实体类 Book.java

package com.example.zhaoxin.commonbaseadapter.entity;

/**
* Created by zhaoxin on 17/11/23.
* 图书实体类
*/

public class Book {

private String bookName;
private String bookPrice;

public Book(){}

public Book(String bookName, String bookPrice) {
this.bookName = bookName;
this.bookPrice = bookPrice;
}

public String getBookName() {
return bookName;
}

public void setBookName(String bookName) {
this.bookName = bookName;
}

public String getBookPrice() {
return bookPrice;
}

public void setBookPrice(String bookPrice) {
this.bookPrice = bookPrice;
}
}

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
主页面布局 activity_main.java

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ListView
android:id="@+id/list"
android:layout_width="match_parent"
android:layout_height="match_parent">
</ListView>
</LinearLayout>

1
2
3
4
5
6
7
8
9
10
列表项布局 item_list.java

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:id="@+id/tv_book_name"
android:layout_width="match_parent"
android:layout_height="wrap_content" />

<TextView
android:id="@+id/tv_book_price"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15