在Android中实现Listview对新人来说比较难以理解,本人看了若干文章后觉得可以使用以下思路来让新人更好理解(同时也做好记录,免得自己以后忘记)。
可参考博客:http://cinderella7.blog.51cto.com/7607653/1281696
(这里用MVC的思想去理解Listview,个人认为还是不错的)
http://blog.csdn.net/jueblog/article/details/11857281
(一个完整的实现)
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一、理顺整个思路。
自定义Listview中包含三个重要概念,这里用MVC的形式去理解:
ListView相当于MVC框架中的V(视图)
Adapter相当于MVC框架中的C(控制器)
数据源相当于MVC框架中的M(模型)
二、一步一步实现
1、先自定义listview中每个Item子项的布局
listitem.xml
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"><ImageView
android:layout_width="fill_parent"
android:layout_height="100dp"
android:id="@+id/imageView"/>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Large Text"
android:id="@+id/textView"/>
</LinearLayout>
2、定义主布局
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<ListView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/listView"/>
</LinearLayout>
3、然后,定义数据源、视图、适配器
private List<HashMap<String,Object>> mData; //M
private ListView listView; //V
private MyAdapter myAdapter; //C
4、获取数据源
private List<HashMap<String,Object>> getData(){
ArrayList<HashMap<String,Object>> arrayList = new ArrayList<HashMap<String, Object>>();
HashMap<String,Object> hashMap = null;
for(int i=0;i<10;i++){
hashMap = new HashMap<String, Object>();
hashMap.put("index",Integer.toString(i+1));
hashMap.put("img",R.drawable.my);
arrayList.add(hashMap); //添加到数据源中
}
return arrayList;
}
5、自定义适配器,添加数据源到适配器中
//创建自定义adapter
private class MyAdapter extends BaseAdapter{
private LayoutInflater mlayoutInflater;
public MyAdapter(Context context) {
mlayoutInflater = LayoutInflater.from(context); //动态布局映射
}@Override
public int getCount() {
return mData.size();
}@Override
public Object getItem(int position) {
return null;
}@Override
public long getItemId(int position) {
return 0;
}@Override
public View getView(int position, View convertView, ViewGroup parent) {
convertView = mlayoutInflater.inflate(R.layout.listitem, null); // 根据布局文件实例化view
TextView tv = (TextView)convertView.findViewById(R.id.textView);
tv.setText(mData.get(position).get("index").toString());
ImageView img = (ImageView)convertView.findViewById(R.id.imageView);
img.setBackgroundResource((Integer)mData.get(position).get("img"));
return convertView;
}
}
6、在onCreate函数中实施
listView = (ListView)findViewById(R.id.listView);
//----
mData = getData();
myAdapter = new MyAdapter(this);
listView.setAdapter(myAdapter);
三、总结
整个实现流程都严格按照MVC的模式去做,首先是自定义自己的元素布局,然后获取数据源,然后重写适配器,加载数据源到适配器中,通过listview显示适配器内容。
以下附上Java代码完整版:
package com.example.ListViewTest;import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;public class MyActivity extends Activity {
/**
* Called when the activity is first created.
*/
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);listView = (ListView)findViewById(R.id.listView);
//----
mData = getData();
myAdapter = new MyAdapter(this);
listView.setAdapter(myAdapter);
}private List<HashMap<String,Object>> mData; //M
private ListView listView; //V
private MyAdapter myAdapter; //Cprivate List<HashMap<String,Object>> getData(){
ArrayList<HashMap<String,Object>> arrayList = new ArrayList<HashMap<String, Object>>();
HashMap<String,Object> hashMap = null;
for(int i=0;i<10;i++){
hashMap = new HashMap<String, Object>();
hashMap.put("index",Integer.toString(i+1));
hashMap.put("img",R.drawable.my);
arrayList.add(hashMap); //添加到数据源中
}
return arrayList;
}//创建自定义adapter
private class MyAdapter extends BaseAdapter{
private LayoutInflater mlayoutInflater;public MyAdapter(Context context) {
mlayoutInflater = LayoutInflater.from(context); //动态布局映射
}@Override
public int getCount() {
return mData.size();
}@Override
public Object getItem(int position) {
return null;
}@Override
public long getItemId(int position) {
return 0;
}@Override
public View getView(int position, View convertView, ViewGroup parent) {
convertView = mlayoutInflater.inflate(R.layout.listitem, null); // 根据布局文件实例化view
TextView tv = (TextView)convertView.findViewById(R.id.textView);
tv.setText(mData.get(position).get("index").toString());
ImageView img = (ImageView)convertView.findViewById(R.id.imageView);
img.setBackgroundResource((Integer)mData.get(position).get("img"));
return convertView;
}
}
}
Android复杂自定义Listview实现,布布扣,bubuko.com