Android之ListView

ListViewActivity以及它的布局文件

package com.example.test0508.ListView;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import androidx.annotation.Nullable;

import com.bumptech.glide.Glide;
import com.example.test0508.R;

import java.util.List;

public class ListViewActivity extends Activity {

    private ListView mLv1;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_list_view);
        mLv1 = findViewById(R.id.lv_1);
        mLv1.setAdapter(new MyListAdapter(ListViewActivity.this));
        /*
            监听 listView 的点击事件
         */
        mLv1.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                Toast.makeText(ListViewActivity.this,"Pos" + i ,Toast.LENGTH_SHORT).show();
            }
        });

        /*
            长按监听事件
         */
        mLv1.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
            @Override
            public boolean onItemLongClick(AdapterView<?> adapterView, View view, int i, long l) {
                Toast.makeText(ListViewActivity.this,"长安点击 Pos" + i,Toast.LENGTH_SHORT).show();
                //告诉别人我处理完了
                return true;
            }
        });
    }
}


class MyListAdapter extends BaseAdapter{

    private Context mContext;
    private LayoutInflater mLayoutInflater;


    public MyListAdapter(Context context) {
        this.mContext = context;
        mLayoutInflater = LayoutInflater.from(context);
    }

    @Override
    public int getCount() {
        return 10;
    }

    @Override
    public Object getItem(int i) {
        return null;
    }

    @Override
    public long getItemId(int i) {
        return 0;
    }

    /*
        相当重要的方法
     */
    static class ViewHolder{
        public ImageView imageView;
        public TextView tvTitle;
        public TextView tvTime;
        public TextView tvContent;
    }
    @Override
    public View getView(int i, View convertView, ViewGroup viewGroup) {
        ViewHolder viewHolder = null;
        if (convertView == null){
            convertView = mLayoutInflater.inflate(R.layout.layout_list_item,null);
            viewHolder = new ViewHolder();
            viewHolder.imageView = convertView.findViewById(R.id.list_iv);
            viewHolder.tvTitle = convertView.findViewById(R.id.list_tv_title);
            viewHolder.tvTime = convertView.findViewById(R.id.list_tv_time);
            viewHolder.tvContent = convertView.findViewById(R.id.list_tv_content);
            convertView.setTag(viewHolder);

        }else {
            viewHolder = (ViewHolder) convertView.getTag();
        }

        //给控件赋值
        viewHolder.tvTitle.setText("这是标题");
        viewHolder.tvTime.setText("这是修改的时间");
        viewHolder.tvContent.setText("这是修改的内容");
        Glide.with(mContext).load("https://ss0.bdstatic.com/94oJfD_bAAcT8t7mm9GUKT-xh_/timg?image&quality=100&size=b4000_4000&sec=1589103035&di=dc1056a67b57cbfd46d2dd6f35a3f2ef&src=http://img.mingxing.com/upload/thumb/2015/09-25/0-eLomMg.jpg").into(viewHolder.imageView);

        return convertView;
    }
}

<?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"
    android:padding="10dp"
    >

    <ListView
        android:id="@+id/lv_1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:listSelector="@drawable/list_item"
    />

</LinearLayout>

---

layout_list_item

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal" android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="15dp"
    android:paddingRight="15dp"
    android:paddingTop="10dp"
    android:paddingBottom="10dp"
    >

    <ImageView
        android:id="@+id/list_iv"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:scaleType="centerCrop"
        android:background="#000000"
        />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:paddingLeft="15dp"
    >
        <TextView
            android:id="@+id/list_tv_title"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Hello"
            android:textSize="20sp"
            android:textColor="@color/colorBlack"
            />

        <TextView
            android:id="@+id/list_tv_time"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="2020-08-26"
            android:textSize="20sp"
            android:textColor="@color/colorBlack"
            android:layout_marginTop="10dp"
            />

        <TextView
            android:id="@+id/list_tv_content"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="这是内容"
            android:textSize="20sp"
            android:textColor="@color/colorBlack"
            android:layout_marginTop="10dp"
            />

    </LinearLayout>

</LinearLayout>

---

在drawable new一个selector（list_item.xml)

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item  android:state_pressed="true" android:drawable="@color/colorGreen" />
<item android:state_pressed="false" android:drawable="@color/colorLittleBlue" />
</selector>