我有 UWP，我在 xaml 上有 ListView。
这是我如何接收 json 的代码，将其设置为 List
public class TopPostsViewModel : INotifyPropertyChanged
{
private List<Child> postsList;
public List<Child> PostsList
{
get { return postsList; }
set { postsList = value; OnPropertyChanged(); }
}
public TopPostsViewModel()
{
Posts_download();
}
public async void Posts_download()
{
string url = "https://www.reddit.com/top/.json?count=50";
var json = await FetchAsync(url);
RootObject rootObjectData = JsonConvert.DeserializeObject<RootObject>(json);
PostsList = new List<Child>(rootObjectData.data.children);
}
private async Task<string> FetchAsync(string url)
{
string jsonString;
using (var httpClient = new System.Net.Http.HttpClient())
{
var stream = await httpClient.GetStreamAsync(url);
StreamReader reader = new StreamReader(stream);
jsonString = reader.ReadToEnd();
}
return jsonString;
}
public event PropertyChangedEventHandler PropertyChanged;
//[NotifyPropertyChangedInvocator]
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
}
在 XAML 中，我像这样显示它：
<ListView x:Name="OrderList" ItemsSource="{Binding PostsList}">
<ListView.ItemTemplate>
<DataTemplate>
<Grid x:Name="GridInf" Height="204" BorderBrush="#FFFBF8F8" BorderThickness="0,0,0,1">
<Image x:Name="Image" HorizontalAlignment="Left" Height="200" Width="200" Tapped="Image_Tapped">
<Image.Source>
<BitmapImage UriSource="{Binding data.thumbnail}" />
</Image.Source>
</Image>
<TextBlock Text="{Binding data.title}" HorizontalAlignment="Left" Margin="252,10,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Height="134" Width="1028"/>
<TextBlock HorizontalAlignment="Left" Margin="252,139,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Height="97" Width="218">
<Run Text="Comments: "/>
<Run Text="{Binding data.num_comments}"/>
</TextBlock>
<TextBlock HorizontalAlignment="Left" Margin="470,134,0,0" TextWrapping="Wrap" Text="TextBlock" VerticalAlignment="Top" Height="102" Width="312"/>
<TextBlock HorizontalAlignment="Left" Margin="787,139,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Height="97" Width="493">
<Run Text="Author: "/>
<Run Text="{Binding data.author}"/>
</TextBlock>
</Grid>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</Grid>
我需要对这个 ListView 进行分页 - 每页只显示 10 个帖子（现在我的列表中有 50 个帖子）
我怎么能做到这一点？
使用两个列表（一个是所有项目，另一个是要显示的 10 个项目）
private List<ItemSource> postsList = new List<ItemSource>(); //Given List
private List<ItemSource> displayPostsList = new List<ItemSource>(); //List to be displayed in ListView
int pageIndex = -1;
int pageSize = 10; //Set the size of the page
private void NextButton_Click(object sender, RoutedEventArgs e)
{
pageIndex++;
displayPostsList = postsList.Skip(pageIndex * pageSize).Take(pageSize).ToList();
}
private void PreviousButton_Click(object sender, RoutedEventArgs e)
{
pageIndex--;
displayPostsList = postsList.Skip(pageIndex * pageSize).Take(pageSize).ToList();
}
//Call NextButton_Click in page Constructor to show defalut 10 items
NextButton_Click(null, null);
不要忘记使用INotifyPropertyChanged以更新 ListViewItems (OR)ObservableCollection代替List并使用此答案转换List为ObservableCollection
本文收集自互联网，转载请注明来源。
如有侵权，请联系 [email protected] 删除。
我来说两句