Android 学习笔记（三）：ListView的使用

listview整理笔记
通过SimpleAdapter来实现listView
主函数代码

public class MainActivity extends AppCompatActivity { private ListView listView; @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_goat);        init();    }    public void init(){        listView  = (ListView) findViewById(R.id.listView);        SimpleAdapter adapter = new SimpleAdapter(this,getData(),R.layout.vlist,                new String[]{"title","img"},                new int[]{R.id.title,R.id.img});        listView.setAdapter(adapter);    }    private List<Map<String, Object>> getData() {        List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();        Map<String, Object> map = new HashMap<String, Object>();        map.put("title", "G1");        map.put("img", R.drawable.pc1);        list.add(map);        map = new HashMap<String, Object>();        map.put("title", "G2");        map.put("img", R.drawable.pc1);        list.add(map);        map = new HashMap<String, Object>();        map.put("title", "G3");        map.put("img", R.drawable.pc1);        list.add(map);        map = new HashMap<String, Object>();        map.put("title", "G4");        map.put("img", R.drawable.pc1);        list.add(map);        return list;    }    }

布局文件代码

<?xml version="1.0" encoding="utf-8"?><android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="com.example.steven.testoct.MainActivity">    <LinearLayout        android:layout_width="250dp"        android:layout_height="300dp"        android:background="@color/colorAccent"        app:layout_constraintBottom_toBottomOf="parent"        app:layout_constraintTop_toTopOf="parent"        app:layout_constraintLeft_toRightOf="@+id/imageView"        android:layout_marginStart="100dp"        app:layout_constraintVertical_bias="0.495">        <android.support.v7.widget.ListViewCompat            android:layout_width="match_parent"            android:layout_height="match_parent"            android:id="@+id/listView">        </android.support.v7.widget.ListViewCompat>    </LinearLayout></android.support.constraint.ConstraintLayout>

自定义内部view片代码
vlist.xml

<?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:id="@+id/img"        android:layout_width="50dp"        android:layout_height="50dp"        />    <TextView android:id="@+id/title"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:textColor="#FFFFFFFF"        /></LinearLayout>

这样就实现了一个基本的带图片与文字的listView。

能够响应点击事件的listview
我们只需要对上述代码进行修改，将原来的simpleAdapter改成一个自定义的Adapter就可以响应
先定义一个数据组，方便后面调用

private List<Map<String,Object>> mData;

随后定义

private final class ViewHolder{        private ImageView img;        private TextView title;    }

再自定义MyAdapter类

private class MyAdapter extends BaseAdapter{        //view片获取        private LayoutInflater mInflater;        private MyAdapter(Context context){            this.mInflater = LayoutInflater.from(context);        }        //获取数组大小        @Override        public int getCount() {            return mData.size();        }        //获取数组        @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 = null;            //获取布局            if (convertView==null){                //重新获取布局                holder = new ViewHolder();                convertView= mInflater.inflate(R.layout.vlist,null);                holder.img =  convertView.findViewById(R.id.img);                holder.title = convertView.findViewById(R.id.title);                convertView.setTag(holder);            }            else {                holder = (ViewHolder) convertView.getTag();            }            //获取数据内容            holder.img.setBackgroundResource((Integer) mData.get(position).get("img"));          holder.title.setText((String) mData.get(position).get("title"));            //设置监听事件            holder.img.setOnClickListener(new View.OnClickListener() {                @Override                public void onClick(View v) {                    startActivity(new Intent(GoatActivity.this,TestActivity.class));                }            });            return  convertView;        }    }

这样我们就可以在OnCreate中引用

        mData = getData();        MyAdapter myAdapter = new MyAdapter(this);        listView.setAdapter(myAdapter);

以下为完整代码，XML文件一致

public class MainActivity extends AppCompatActivity {    private ImageView imageView7;    private ListView listView;    private List<Map<String,Object>> mData;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_goat);        init();    }    public void init(){        listView  = (ListView) findViewById(R.id.listView);//        SimpleAdapter adapter = new SimpleAdapter(this,getData(),R.layout.vlist,//                new String[]{"title","img"},//                new int[]{R.id.title,R.id.img});//        listView.setAdapter(adapter);        mData = getData();        MyAdapter myAdapter = new MyAdapter(this);        listView.setAdapter(myAdapter);    }    //Map    private List<Map<String, Object>> getData() {        List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();        Map<String, Object> map = new HashMap<String, Object>();        map.put("title", "G1");        map.put("img", R.drawable.pc1);        list.add(map);        map = new HashMap<String, Object>();        map.put("title", "G2");        map.put("img", R.drawable.pc1);        list.add(map);        map = new HashMap<String, Object>();        map.put("title", "G3");        map.put("img", R.drawable.pc1);        list.add(map);        map = new HashMap<String, Object>();        map.put("title", "G4");        map.put("img", R.drawable.pc1);        list.add(map);        return list;    }    private final class ViewHolder{        private ImageView img;        private TextView title;    }    private class MyAdapter extends BaseAdapter{        //view片获取        private LayoutInflater mInflater;        private MyAdapter(Context context){            this.mInflater = LayoutInflater.from(context);        }        //获取数组大小        @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) {            ViewHolder holder = null;            //获取布局            if (convertView==null){                //重新获取布局                holder = new ViewHolder();                convertView= mInflater.inflate(R.layout.vlist,null);                holder.img =  convertView.findViewById(R.id.img);                holder.title = convertView.findViewById(R.id.title);                convertView.setTag(holder);            }            else {                holder = (ViewHolder) convertView.getTag();            }            //获取数据内容            holder.img.setBackgroundResource((Integer) mData.get(position).get("img"));          holder.title.setText((String) mData.get(position).get("title"));            //设置监听事件            holder.img.setOnClickListener(new View.OnClickListener() {                @Override                public void onClick(View v) {                    startActivity(new Intent(MainActivity.this,TestActivity.class));                }            });            return  convertView;        }    }}