ListView中显示不同的视图布局实现重用

新年的第一篇博客，我就和大家谈一谈在Android开发中当ListView中的每一个Item需要显示不同布局时如何去实现，并且实现重用，废话不多说，先看看具体代码：

1、首先写3个不同的布局作为ListView中的Item:

（1）list_item1.xml

<?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/item1_txt"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="20sp"
        android:textColor="#000000"
        android:padding="20dp"/>

</LinearLayout>

（2）list_item2.xml

<?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/item2_txt"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="20sp"
        android:textColor="#000000"
        android:padding="20dp"/>

    <SeekBar
        android:id="@+id/seekBar1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" 
        android:paddingLeft="20dp"/>

</LinearLayout>

（3）list_item3.xml

<?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/item3_txt"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="20sp"
        android:textColor="#000000"
        android:padding="20dp"/>

    <RatingBar
        android:id="@+id/ratingBar1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" 
        android:layout_marginLeft="20dp"/>

</LinearLayout>

2、为ListView自定义适配器MultiItemAdapter.java，这里是重点！具体代码如下：

package com.example.multiitemlistview;

import java.util.ArrayList;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.CheckBox;
import android.widget.RatingBar;
import android.widget.TextView;

public class MultiItemAdapter extends BaseAdapter {
	
	private Context context;
	private ArrayList<String> listString = new ArrayList<String>();
	private final int TYPE_COUNT = 3;
	private final int TYPE_ONE = 0;
	private final int TYPE_TWO = 1;
	private final int TYPE_THREE = 2;
	
	public MultiItemAdapter(Context context, ArrayList<String> dataString) {
		this.context = context;
		this.listString = dataString;
	}

	@Override
	public int getCount() {
		return listString.size();
	}
	
	/**
	 * 每个convertview都会调用此方法，获得当前所需要的view样式
	 */
	@Override
	public int getItemViewType(int position) {
		return position%3;
	}

	@Override
	public int getViewTypeCount() {
		return TYPE_COUNT;
	}

	@Override
	public Object getItem(int arg0) {
		return listString.get(arg0);
	}

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

	@Override
	public View getView(int position, View convertView, ViewGroup parent) {
		viewHolder1 holder1 = null;
		viewHolder2 holder2 = null;
		viewHolder3 holder3 = null;
		int type = getItemViewType(position);
		if (convertView == null) {
			//按当前所需的样式，确定new的布局
			switch (type) {
			case TYPE_ONE:
				convertView = LayoutInflater.from(context).inflate(R.layout.list_item1, null);
				holder1 = new viewHolder1();
				holder1.textView = (TextView) convertView.findViewById(R.id.item1_txt);
				convertView.setTag(holder1);
				break;
			case TYPE_TWO:
				convertView = LayoutInflater.from(context).inflate(R.layout.list_item2, null);
				holder2 = new viewHolder2();
				holder2.textView = (TextView) convertView.findViewById(R.id.item2_txt);
				convertView.setTag(holder2);
				break;
			case TYPE_THREE:
				convertView = LayoutInflater.from(context).inflate(R.layout.list_item3, null);
				holder3 = new viewHolder3();
				holder3.textView = (TextView) convertView.findViewById(R.id.item3_txt);
				convertView.setTag(holder3);
				break;
			default:
				break;
			}
		} else {
			switch (type) {
			case TYPE_ONE:
				holder1 = (viewHolder1) convertView.getTag();
				break;
			case TYPE_TWO:
				holder2 = (viewHolder2) convertView.getTag();
				break;
			case TYPE_THREE:
				holder3 = (viewHolder3) convertView.getTag();
				break;
			default:
				break;
			}
		}
		
		switch (type) {
		case TYPE_ONE:
			holder1.textView.setText(listString.get(position));
			break;
		case TYPE_TWO:
			holder2.textView.setText(listString.get(position));
			break;
		case TYPE_THREE:
			holder3.textView.setText(listString.get(position));
			break;
		default:
			break;
		}
		return convertView;
	}

	//各个布局的控件资源
	class viewHolder1{
		TextView textView;
	}

	class viewHolder2{
		TextView textView;
		CheckBox checkBox;
	}

	class viewHolder3{
		TextView textView;
		RatingBar ratingBar;
	}
}

3、在主界面中为ListView填充数据，具体代码很简单，如下所示：

（1）主界面的布局activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ListView 
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:id="@+id/main_list"/>

</RelativeLayout>

（2）主界面实现代码：

package com.example.multiitemlistview;

import java.util.ArrayList;

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

public class MainActivity extends Activity {
	
	private ListView mainList;
	private ArrayList<String> dataString;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		mainList = (ListView) findViewById(R.id.main_list);
		
		dataString = new ArrayList<String>();
		for (int i = 1; i < 100; i++) {
			dataString.add("ListItem--->" + i);
		}
		
		mainList.setAdapter(new MultiItemAdapter(getApplicationContext(), dataString));
	}

}

好了，到这里一切就结束了，这是完整的Demo下载地址：http://download.youkuaiyun.com/detail/flymoon1201/8478811

下面来看看这个Demo的效果图：