Android复杂自定义Listview实现

时间:2014-05-19 13:43:46   收藏:0   阅读:410

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

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<?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>
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  2、定义主布局

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<?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>
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  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

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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;
    }
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  5、自定义适配器,添加数据源到适配器中

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//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; } }
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  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:

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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;  //C


    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;
    }

    //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;
        }
    }
}
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Android复杂自定义Listview实现,布布扣,bubuko.com

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