android适配器之基于BaseAdapt自定义简单适配器

代码样例：

一布局文件

二自定义ListView布局文件

<?xml version="1.0" encoding="utf-8"?>

三自定义适配器

package com.example.listview;import java.util.List;import android.content.Context;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.TextView;public class MyAdapt extends BaseAdapter {private Context context;private List list;int count = 0;public MyAdapt(Context context,List list){this.context = context;this.list = list;}@Overridepublic int getCount() {// TODO Auto-generated method stubreturn list.size();}@Overridepublic Object getItem(int position) {// TODO Auto-generated method stubreturn list.get(position);}@Overridepublic long getItemId(int position) {// TODO Auto-generated method stubreturn 0;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {View view = View.inflate(context, R.layout.mylayout, null);TextView textView = (TextView) view.findViewById(R.id.tv);textView.setText(list.get(position)+"");return view;}}

四 MainActivity

package com.example.listview;import java.util.ArrayList;import java.util.List;import android.app.Activity;import android.os.Bundle;import android.widget.ListView;public class MainActivity extends Activity {private ListView listView;private List list;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);listView = (ListView)findViewById(R.id.lv);list = new ArrayList<>();for (int i = 0; i < 100; i++) {list.add(i);}listView.setAdapter(new MyAdapt(this, list));}}

五总结

这种方式在数据量大的时候ListView的效率极低，显示每行数据都要重复执行一遍MyAdapt中的getView方法，其中除了要传递的数据不一样，样式等其他的都一样，所以这样效率非常低下。但是这种方法对于初学者来说比较好理解。到后面也要对这个ListView进行优化。

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