废话不多说, 上图:

GIF.gif

上思路:

动态改变数据适配器中的getCount()方法的返回值;

点击刷新适配器中的数据;

注意:

1.这是在普通的布局中实现;

2.如需要在ScrollView中实现该功能, 需要解决嵌套产生的ListView条目显示不全问题;

3.请看下一篇文章介绍;

上代码:

代码01 - listview条目布局的xml:

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:padding="10dp"

android:orientation="horizontal">

android:id="@+id/icon"

android:layout_width="40dp"

android:layout_height="40dp"

android:layout_marginRight="10dp"

android:src="@drawable/icon2" />

android:id="@+id/name"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_gravity="center_vertical"

android:textSize="16sp"

android:text="陈坤" />

效果图:

ListView条目布局效果图.png

代码02 - mainActivity的布局文件xml:

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"

android:orientation="vertical"

tools:context="com.geaosu.myapplication.MainActivity">

android:id="@+id/list"

android:layout_width="match_parent"

android:layout_height="wrap_content">

android:id="@+id/loadMore"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:background="#A4D3FF"

android:gravity="center_horizontal"

android:paddingBottom="20dp"

android:paddingTop="20dp"

android:textSize="16sp" />

效果图:

MainActivity布局效果图.png

代码03 - MainActivity代码

package com.geaosu.myapplication;

import android.os.Bundle;

import android.support.v7.app.AppCompatActivity;

import android.view.View;

import android.view.ViewGroup;

import android.widget.BaseAdapter;

import android.widget.ImageView;

import android.widget.ListView;

import android.widget.TextView;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

private ListView list;

private TextView loadMore;

private String[] arr1 = {"geaosu01", "geaosu02", "geaosu03", "geaosu04", "geaosu05"};

private boolean isShowMore = false;

private MoreAdapter moreAdapter;

private int mCount = 1;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

list = findViewById(R.id.list);

moreAdapter = new MoreAdapter();

list.setAdapter(moreAdapter);

loadMore = findViewById(R.id.loadMore);

loadMore.setOnClickListener(this);

loadMore.setText("点击展开");

}

@Override

public void onClick(View view) {

switch (view.getId()) {

case R.id.loadMore:

if (isShowMore) {

loadMore.setText("点击展开");

} else {

loadMore.setText("点击收起");

}

isShowMore = !isShowMore;

moreAdapter.notifyDataSetChanged();

break;

}

}

private class MoreAdapter extends BaseAdapter {

@Override

public int getCount() {

// 重点区域

if (isShowMore) {

return arr1.length;

} else {

return mCount;

}

}

@Override

public Object getItem(int i) {

return arr1[i];

}

@Override

public long getItemId(int i) {

return i;

}

@Override

public View getView(int i, View view, ViewGroup viewGroup) {

View itemView = View.inflate(MainActivity.this, R.layout.item_list, null);

TextView name = itemView.findViewById(R.id.name);

ImageView icon = itemView.findViewById(R.id.icon);

name.setText(arr1[i]);

return itemView;

}

}

}

============== 结束 ==============

努力让世界变得更好 ------ geaosu