ListView局部更新

notifyDataSetChanged（）方法调用更新的是可见区域的所有子view。

那可以尝试只更新某个position的子view

核心方法，在自定义adapter加一个方法：

		public void upatePosition(int position) {// 只更新listview某一项
			int visitFirstPositon = mListView.getFirstVisiblePosition();
			int visitLastPositon = mListView.getLastVisiblePosition();
			if (position >= visitFirstPositon && position <= visitLastPositon) {// 要更新的item已经显示在界面上
				getView(position,
						mListView.getChildAt(position - visitFirstPositon),
						mListView);
			}
		}

对比测试：

1.调用notifyDataSetChanged方法打印的getView的log：

2.新写的局部刷新

可见，传统的notifyDataSetChanged是更新了可视区域所有子view，而局部刷新只更新了某个位置。

测试代码很简单，布局就一个listview和两个按钮

主要的测试activity:

package com.example.listview111;

import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;

public class MainActivity extends Activity implements OnClickListener {
	private ListView mListView;
	private MyAdapter mAdaAdapter;
	private Button mBu1, mBu2;
	private String[] data;

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

	private void initData() {
		mBu1.setOnClickListener(this);
		mBu2.setOnClickListener(this);
		data = new String[20];
		for (int i = 0; i < data.length; i++) {
			data[i] = "item" + i;
		}
		mAdaAdapter = new MyAdapter();
		mListView.setAdapter(mAdaAdapter);
	}

	private void changed1() {//传统方式
		data[0] = data[0] + "-change1";
		data[data.length - 1] = data[data.length - 1] + "-change1";
		Log.d("chaged1() ", "传统使用notifyDataSetChanged（）");
		mAdaAdapter.notifyDataSetChanged();
	}

	private void changed2() {//局部刷新
		data[0] = data[0] + "-change2";
		data[data.length - 1] = data[data.length - 1] + "-change2";
		Log.d("chaged2() ", "新写的局部更新");
		mAdaAdapter.upatePosition(0);
		mAdaAdapter.upatePosition(data.length - 1);
	}

	@Override
	public void onClick(View v) {
		switch (v.getId()) {
		case R.id.main_bu1:
			changed1();
			break;
		case R.id.main_bu2:
			changed2();
			break;
		}
	}

	private void initView() {
		mListView = (ListView) findViewById(R.id.main_lsitview);
		mBu1 = (Button) findViewById(R.id.main_bu1);
		mBu2 = (Button) findViewById(R.id.main_bu2);
	}

	class MyAdapter extends BaseAdapter {

		@Override
		public int getCount() {
			return data.length;
		}

		@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) {
			ViewHolder holder;
			Log.d("adapter", "getView() " + position + " convertView==null?"
					+ (convertView == null));
			if (convertView == null) {
				convertView = LayoutInflater.from(MainActivity.this).inflate(
						android.R.layout.simple_list_item_1, null);
				holder = new ViewHolder();
				holder.textView = (TextView) convertView
						.findViewById(android.R.id.text1);
				convertView.setTag(holder);
			} else {
				holder = (ViewHolder) convertView.getTag();
			}
			holder.textView.setText(data[position]);
			return convertView;
		}

		public void upatePosition(int position) {// 只更新listview某一项
			int visitFirstPositon = mListView.getFirstVisiblePosition();
			int visitLastPositon = mListView.getLastVisiblePosition();
			if (position >= visitFirstPositon && position <= visitLastPositon) {// 要更新的item已经显示在界面上
				getView(position,
						mListView.getChildAt(position - visitFirstPositon),
						mListView);
			}
		}

		class ViewHolder {
			TextView textView;
		}

	}

}

参考：http://blog.youkuaiyun.com/wu_shu_jun/article/details/7794576