是否有可能，如果单击其中一项，会显示一个进度条，该进度条会在一定的时间间隔（比如说 30 秒）内从左到右平滑加载？
如果你想在点击Listview项时显示进度条，我给你做了一个例子，你可以看看：
1.声明ListView布局
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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" android:orientation="vertical">
<ListView
android:minWidth="25px"
android:minHeight="25px"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/ListView" />
</LinearLayout>
2.声明列表行布局
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView android:id="@+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<ProgressBar android:id="@+id/progressBar1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true" android:visibility="invisible"
style="@android:style/Widget.ProgressBar.Horizontal" />
</LinearLayout>
3.定义ListView适配器
public class Post
{
public string title { get; set; }
public bool isselect { get; set; }
}
public class CusotmListAdapter : BaseAdapter<Post>
{
Activity context;
List<Post> list;
public CusotmListAdapter(Activity _context, List<Post> _list)
: base()
{
this.context = _context;
this.list = _list;
}
public override Post this[int position]
{
get { return list[position]; }
}
public override int Count
{
get { return list.Count; }
}
public override long GetItemId(int position)
{
return position;
}
public override View GetView(int position, View convertView, ViewGroup parent)
{
View view = convertView;
// re-use an existing view, if one is available
// otherwise create a new one
if (view == null)
view = context.LayoutInflater.Inflate(Resource.Layout.ListItemRow, parent, false);
Post item = this[position];
view.FindViewById<TextView>(Resource.Id.textView1).Text = item.title;
if(item.isselect==true)
{
view.FindViewById<ProgressBar>(Resource.Id.progressBar1).Visibility = ViewStates.Visible;
}
else
{
view.FindViewById<ProgressBar>(Resource.Id.progressBar1).Visibility = ViewStates.Invisible;
}
return view;
}
}
-
设置 ListView 适配器
public class MainActivity : AppCompatActivity
{
private ListView listview;
List<Post> posts = new List<Post>();
private CusotmListAdapter adapter;
private int oldposition = -1;
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
// Set our view from the "main" layout resource
posts.Add(new Post() { title = "title 1", isselect = false });
posts.Add(new Post() { title = "title 2", isselect = false });
posts.Add(new Post() { title = "title 3", isselect = false });
posts.Add(new Post() { title = "title 4", isselect = false });
posts.Add(new Post() { title = "title 5", isselect = false });
posts.Add(new Post() { title = "title 6", isselect = false });
posts.Add(new Post() { title = "title 7", isselect = false });
posts.Add(new Post() { title = "title 8", isselect = false });
SetContentView(Resource.Layout.activity_main);
listview = FindViewById<ListView>(Resource.Id.ListView);
listview.ItemClick+= OnListItemClick;
adapter= new CusotmListAdapter(this, posts);
listview.Adapter = adapter;
}
private void OnListItemClick(object sender, AdapterView.ItemClickEventArgs e)
{
if(oldposition!=-1)
{
Post p1 = adapter[oldposition];
p1.isselect = false;
}
oldposition = e.Position;
Post p = adapter[e.Position];
p.isselect = true;
adapter.NotifyDataSetChanged();
}
}
如果我的回复对你有帮助，请记得将我的回复标记为答案，谢谢。
更新：
您可以在 CusotmListAdapter GetView 事件中更改一些代码，请查看：
public override View GetView(int position, View convertView, ViewGroup parent)
{
View view = convertView;
// re-use an existing view, if one is available
// otherwise create a new one
if (view == null)
view = context.LayoutInflater.Inflate(Resource.Layout.ListItemRow, parent, false);
Post item = this[position];
view.FindViewById<TextView>(Resource.Id.textView1).Text = item.title;
ProgressBar p = view.FindViewById<ProgressBar>(Resource.Id.progressBar1);
p.Max = 100;
p.Progress = 100;
//p.IncrementProgressBy(-10);
if(item.isselect==true)
{
view.FindViewById<ProgressBar>(Resource.Id.progressBar1).Visibility = ViewStates.Visible;
new Thread(new ThreadStart(delegate
{
while (p.Progress > 0)
{
p.Progress -= 20;
Thread.Sleep(1000);
}
})).Start();
}
else
{
view.FindViewById<ProgressBar>(Resource.Id.progressBar1).Visibility = ViewStates.Invisible;
}
return view;
}
那么请看截图：