ListView-白红宇

ListView

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发布时间：2019-06-22

本文共 4039 字，大约阅读时间需要 13 分钟。

package com.zyeq.cxsw.listview_3;import android.graphics.Color;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;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 android.widget.Toast;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;public class MainActivity extends AppCompatActivity {    private int[] ids={R.drawable.img_1,R.drawable.img_2,R.drawable.img_3,R.drawable.img_4,R.drawable.img_5,R.drawable.img_6,R.drawable.img_7,R.drawable.img_8,R.drawable.img_9,R.drawable.img_10};    private ListView listView;    private List
       
        > data = new ArrayList<>();    private int temp;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        listView = (ListView) this.findViewById(R.id.listView);        /*加载数据*/        data=loadData();        /*创建适配器*/        MyAdapter adapter=new MyAdapter();        /*设置适配器*/        listView.setAdapter(adapter);    }    /*使用BasicAdapter*/    class MyAdapter extends BaseAdapter {        /*返回数据的条数*/        @Override        public int getCount() {            return data.size();        }        /*返回一个对象*/        @Override        public Object getItem(int position) {            return null;        }        /*返回代表当前item项的id*/        @Override        public long getItemId(int position) {            return position;        }        /**/        @Override        public View getView(int position, View convertView, ViewGroup parent) {            temp=position;            /*将布局转化为一个View对象*/            /*1.获取布局加载器*/            /*ListView的优化操作：1.复用布局 2.减少findViewById的次数            * */            View view=convertView;            ViewHolder viewHolder;            if(view==null){                view = getLayoutInflater().inflate(R.layout.list_item, parent, false);                  /*从布局文件中获取UI控件*/                viewHolder=new ViewHolder();                TextView textView= (TextView) view.findViewById(R.id.name);                ImageView imageView= (ImageView) view.findViewById(R.id.logo);                viewHolder.setImageView(imageView);                viewHolder.setTextView(textView);                view.setTag(viewHolder);            }            viewHolder= (ViewHolder) view.getTag();            viewHolder.getTextView().setText(data.get(position).get("name"));            /*为图片设置监听器*/            viewHolder.getImageView().setOnClickListener(new View.OnClickListener() {                @Override                public void onClick(View v) {                    Toast.makeText(getApplicationContext(), "id:" + data.get(temp).get("logo"), Toast.LENGTH_SHORT).show();                }            });            /*设置字体的颜色*/            if(position==9){                viewHolder.getTextView().setTextColor(Color.RED);            }            viewHolder.getImageView().setImageResource(Integer.parseInt(data.get(position).get("logo")));            return view;        }        /*封装控件*/        class ViewHolder{            private TextView textView;            private ImageView imageView;            public TextView getTextView() {                return textView;            }            public void setTextView(TextView textView) {                this.textView = textView;            }            public ImageView getImageView() {                return imageView;            }            public void setImageView(ImageView imageView) {                this.imageView = imageView;            }        }    }    /*需要的数据源*/    public List
        
         
          > loadData() {        List
          
           
            > list = new ArrayList<>(); Map
            
              map = null; for (int i = 1; i <= 1000; i++) { map=new HashMap<>(); map.put("name", "user" + i); map.put("logo",""+ids[i%10]); list.add(map); } return list; }}