xamarin下用c#开发安卓的listvew翻页功能
listview的翻页用到了几个知识点,1数据的填充,2翻页图片的加载,3页码的计算,实际效果如下图:
axml文件有两个,一个是主界面Main.axml,另一个是显示“加载中。。。。”这个layout1.axml
Main.axml代码如下:
<?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"
android:minWidth="25px"
android:minHeight="25px">
<ListView
android:minWidth="25px"
android:minHeight="25px"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/listView1" />
</LinearLayout>
layout1.axml代码如下:
<?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"
android:minWidth="25px"
android:minHeight="25px">
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/linearLayout1"
android:gravity="center">
<ProgressBar
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:id="@+id/progressBar1" />
<TextView
android:text="加载中......"
android:textAppearance="?android:attr/textAppearanceLarge"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:id="@+id/textView1" />
</LinearLayout>
</LinearLayout>
程序文件MainActivity.CS 如下:
using Android.App;
using Android.Widget;
using Android.OS;
using System.Collections.Generic;
using Android.Runtime;
using Android.Views;
namespace App12
{
[Activity(Label = "App12", MainLauncher = true)]
public class MainActivity : Activity
{
ListView list_member;
SimpleAdapter content;
int visiablecount;
int totalcount;
int first;
View foot ;
int pageindex =1 ;//当前页码
int pagesize =10; //每页的条数
IList<IDictionary<string, object>> data;
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
SetContentView(Resource.Layout.Main);
list_member = FindViewById<ListView>(Resource.Id.listView1);
//填充数据
FillDate();
//显示加载更多
// LayoutInflater inflater = LayoutInflater.UnregisterFromRuntime(this);
LayoutInflater inflater = LayoutInflater.FromContext(this);
foot = inflater.Inflate(Resource.Layout.layout1,null);
list_member.AddFooterView(foot);
//隐藏底部的加载图标
foot.Visibility = ViewStates.Gone;
//listview拉倒底部
list_member.Scroll += List_member_Scroll;
// 滚动条状态变化
list_member.ScrollStateChanged += List_member_ScrollStateChanged;
}
private void List_member_ScrollStateChanged(object sender, AbsListView.ScrollStateChangedEventArgs e)
{
// throw new System.NotImplementedException();
//判断是否停止滚动
if (e.ScrollState == ScrollState.Idle && (first+visiablecount)==totalcount )
{
// Toast.MakeText(this, "滚动条停下来了!", ToastLength.Long).Show();
foot.Visibility = ViewStates.Visible; //显示加载下一页
pageindex++;
FillDate(); //填充数据到下页
}
}
private void List_member_Scroll(object sender, AbsListView.ScrollEventArgs e)
{
//throw new System.NotImplementedException();
first = e.FirstVisibleItem; //第一项的编号
totalcount = e.TotalItemCount;//列表总条数
visiablecount = e.VisibleItemCount;//每页条数
}
public void FillDate()
{
int PageEnd = pageindex * pagesize + 1; //当前页最后一条数据的编号
int PageStart = (pageindex - 1) * pagesize;//当前页最后一项的编号
data = new List<IDictionary<string, object>>();
//本程序会跟着 pageindex++无限循环翻页
for (int i = 3; i < PageEnd; i++){
//我这里面的数据是写死的,有数据库的同学可以连数据库
JavaDictionary<string, object> achievement = new JavaDictionary<string, object>();
achievement.Add("title", "你好,我是张" + i);
achievement.Add("number","座号"+i);
data.Add(achievement);
}
//创建数据适配器
content = new SimpleAdapter(
this,
data,
Android.Resource.Layout.SimpleListItem2,
new string[] { "title", "number" },
new int[] { Android.Resource.Id.Text1, Android.Resource.Id.Text2 });
//把数据绑定到list_member 这个listview上
list_member.Adapter = content;
list_member.SetSelection(PageStart); //当前页第一项从哪页开始
}
}
}
这个程序调试了一段时间,希望大家玩的开心!
日行一善!
本项目在csdn的下载地址:
https://download.csdn.net/download/u014194297/10328782