现在我以listview为例来讲述下拉刷新的功能！
在xaml中设置listview一定要设置一个这样的属性，IsSwipeEnabled=false,然后再listview控件的前面要布局下拉刷新的图标及提示,在listview控件的后面也要布局上拉时的提示信息。
现在我将个人的布局展现出来，仅供大家参考！
<Grid Name="layoutCtlRoot" MinWidth="240">
<Grid.RowDefinitions>
<RowDefinition Height="Auto"></RowDefinition>
<RowDefinition Height="*"></RowDefinition>
<RowDefinition Height="Auto"></RowDefinition>
</Grid.RowDefinitions>
<Border Name="recRefresh" Height="0" Margin="0" MaxHeight="800" VerticalAlignment="Bottom">
<Grid>
<Grid Margin="10" VerticalAlignment="Bottom">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="64"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<StackPanel VerticalAlignment="Bottom" HorizontalAlignment="Center">
<Image Name="imgArrow" Style="{StaticResource ProgressArrowStyle}">
<Image.RenderTransform>
<RotateTransform x:Name="imageRotateTransform" Angle="0"/>
</Image.RenderTransform>
</Image>
<ProgressRing Name="prgRefresh" Style="{StaticResource ProgressRingStyle}"/>
</StackPanel>
<StackPanel VerticalAlignment="Bottom" Grid.Column="1">
<TextBlock Name="txtOperationTip" Style="{StaticResource TipsContentStyle}"/>
<TextBlock Name="txtOperationTime" Style="{StaticResource TipsContentStyle}"/>
</StackPanel>
</Grid>
<Border Background="#99999999" VerticalAlignment="Bottom" Height="1"/>
</Grid>
</Border>
<ListView Name="ForumList" Grid.Row="1" IsSwipeEnabled="False" ItemContainerStyle="{StaticResource ListItemBaseStyle}"/>
<Border Name="recLoad" Height="0" Grid.Row="2" MaxHeight="800">
<Grid VerticalAlignment="Top" Margin="0,10">
<Border Background="#99999999" VerticalAlignment="Top" Height="1"/>
<StackPanel Name="splNextPageLoading" HorizontalAlignment="Center" Orientation="Horizontal" Visibility="Collapsed">
<ProgressRing Style="{StaticResource ProgressRingStyle}" Visibility="Visible"/>
<TextBlock Text="正在加载…" Margin="13" Style="{StaticResource TipsContentStyle}"/>
</StackPanel>
</Grid>
</Border>
</Grid>
然后在后台就要实现下拉刷新的正真效果呢!
这里特别要指出的要注册这样一个事件, this.LayoutUpdated += ForumList_LayoutUpdated;不然就实现不了!
也要注册listview的触摸事件，例如：
this.ForumList.ManipulationStarted+=ForumList_ManipulationStarted;
this.ForumList.ManipulationDelta+=ForumList_ManipulationDelta;
this.ForumList.ManipulationCompleted+=ForumList_ManipulationCompleted;
思路就是这样的,现在我就讲后台的逻辑也给大家参考!
DispatcherTimer toptimer = new DispatcherTimer();
DispatcherTimer timer = new DispatcherTimer();
private ScrollViewer listViewScrollViewer; private double listviewItemHeight = -;
private int optLimitHeight = ;
private bool isInPrpcessing = false; private Point eventStartPoint; private double lastDeltaHandledY = ; private ObservableCollection<dynamic> listDataItems = new ObservableCollection<dynamic>(); //移动开始位置
private Point moveStartPoint;
//是否可以移动
private bool canMove = false; public ListPage()
{
this.InitializeComponent(); this.imgArrow.Source = new BitmapImage(new Uri(@"ms-appx:///Assets/pullrefresh_arrow.png",UriKind.RelativeOrAbsolute));
this.LayoutUpdated += ForumList_LayoutUpdated;
this.recRefresh.SizeChanged+=recRefresh_SizeChanged;
this.ForumList.ManipulationStarted+=ForumList_ManipulationStarted;
this.ForumList.ManipulationDelta+=ForumList_ManipulationDelta;
this.ForumList.ManipulationCompleted+=ForumList_ManipulationCompleted;
//this.ForumList.SelectionChanged+=ForumList_SelectionChanged;
}
private void ForumList_LayoutUpdated(object sender, object e)
{
if (this.Height.Equals(double.NaN) && this.Parent != null)
{
this.Height = ((Windows.UI.Xaml.FrameworkElement)(this.Parent)).ActualHeight;
} if (listViewScrollViewer == null)
{
listViewScrollViewer = FindVisualElement<ScrollViewer>(VisualTreeHelper.GetParent(this));
listViewScrollViewer.ManipulationMode = ManipulationModes.All;
} for (int i = ; i < this.ForumList.Items.Count; i++)
{
ListViewItem item = this.ForumList.ItemContainerGenerator.ContainerFromIndex(i) as ListViewItem; if (item != null && item.ManipulationMode != ManipulationModes.All)
{
item.ManipulationMode = ManipulationModes.All; if (listviewItemHeight < )
{
listviewItemHeight = ((Windows.UI.Xaml.FrameworkElement)(item)).ActualHeight;
}
}
}
} private static T FindVisualElement<T>(DependencyObject container) where T : DependencyObject
{
Queue<DependencyObject> childQueue = new Queue<DependencyObject>();
childQueue.Enqueue(container); while (childQueue.Count > )
{
DependencyObject current = childQueue.Dequeue(); T result = current as T;
if (result != null && result != container)
{
return result;
} int childCount = VisualTreeHelper.GetChildrenCount(current);
for (int childIndex = ; childIndex < childCount; childIndex++)
{
childQueue.Enqueue(VisualTreeHelper.GetChild(current, childIndex));
}
} return null;
}
private void recRefresh_SizeChanged( object sender,SizeChangedEventArgs e)
{
if (e.NewSize.Height > this.optLimitHeight && !isInPrpcessing)
{
if (!this.txtOperationTip.Text.Equals("松开刷新…"))
{
this.txtOperationTip.Text = "松开刷新…";
this.ImgStoryBoard.Begin();
}
}
} private void ForumList_ManipulationStarted(object sender, ManipulationStartedRoutedEventArgs e)
{
eventStartPoint = e.Position;
lastDeltaHandledY = 0;
if (!isInPrpcessing)
{
this.txtOperationTip.Text = "下拉刷新列表…";
}
e.Handled = true;
}
private void ForumList_ManipulationDelta(object sender,ManipulationDeltaRoutedEventArgs e)
{
double offset = e.Cumulative.Translation.Y - lastDeltaHandledY;
if (listViewScrollViewer.VerticalOffset < 3)
{
double height = recRefresh.Height + offset;
recRefresh.Height = height > 0 ? height : 0;
if (offset < 0 && recRefresh.Height <= 0)
{
//向上滑动且刷新Panel未显示时滚动条下移
listViewScrollViewer.ScrollToVerticalOffset(listViewScrollViewer.VerticalOffset-offset/listviewItemHeight);
}
}
else if (listViewScrollViewer.VerticalOffset >= listViewScrollViewer.ScrollableHeight - 1)
{
double height = recLoad.Height - offset;
recLoad.Height = height > 0 ? height : 0;
if (offset > 0 && recLoad.Height <= 0)
{
listViewScrollViewer.ScrollToVerticalOffset(listViewScrollViewer.VerticalOffset - offset / listviewItemHeight);
}
}
else
{
listViewScrollViewer.ScrollToVerticalOffset(listViewScrollViewer.VerticalOffset-offset/listviewItemHeight);
}
lastDeltaHandledY = e.Cumulative.Translation.Y;
e.Handled = true;
} private void ForumList_ManipulationCompleted(object sender, ManipulationCompletedRoutedEventArgs e)
{
if (listViewScrollViewer != null)
{
double offset = listViewScrollViewer.VerticalOffset;
double total = listViewScrollViewer.ScrollableHeight;
if (offset <= 3 || offset > total - 2)
{
DoListItemsSwipe();
}
}
}
/// <summary>
/// 数据加载后是否可下拉刷新
/// </summary>
public static readonly DependencyProperty RefreshableProperty = DependencyProperty.Register("Refreshable", typeof(bool), typeof(ListPage), new PropertyMetadata(true));
public bool Refreshable
{
get
{
return (bool)base.GetValue(RefreshableProperty);
}
set
{
base.SetValue(RefreshableProperty, value); if (!value)
{
this.imgArrow.Visibility = Windows.UI.Xaml.Visibility.Collapsed;
this.prgRefresh.Visibility = Windows.UI.Xaml.Visibility.Collapsed;
this.txtOperationTip.Visibility = Windows.UI.Xaml.Visibility.Collapsed;
this.txtOperationTime.Visibility = Windows.UI.Xaml.Visibility.Collapsed;
}
}
}
private void DoListItemsSwipe()
{
if (recRefresh.Height > 0)
{
if (recRefresh.Height > optLimitHeight && this.Refreshable)
{
recRefresh.Height = 96;
imgArrow.Visibility = Visibility.Collapsed;
prgRefresh.Visibility = Visibility.Visible;
if (!this.isInPrpcessing)
{
System.Diagnostics.Debug.WriteLine(this.isInPrpcessing);
DoListDataSourceRefresh();
}
}
else
{
recRefresh.Height = 0;
}
listViewScrollViewer.ScrollToVerticalOffset(2.05);
}
if (recLoad.Height > 0)
{
if (recLoad.Height > optLimitHeight)
{
recLoad.Height = 68;
splNextPageLoading.Visibility = Visibility.Visible;
if (!this.isInPrpcessing)
{
DoListDataLoadNextPage();
}
}
else
{
recLoad.Height = 0;
}
}
}
private void DoListDataSourceRefresh()
{ this.isInPrpcessing = true;
this.txtOperationTip.Text = "加载数据中";
this.isInPrpcessing = false;
this.recRefresh.Height = 0;
this.imgArrow.Visibility = Windows.UI.Xaml.Visibility.Visible;
this.prgRefresh.Visibility = Windows.UI.Xaml.Visibility.Collapsed;
this.ImgStoryBoard.Begin(); //箭头复位
}
private void DoListDataLoadNextPage()
{
this.recLoad.Height = 0;
splNextPageLoading.Visibility = Windows.UI.Xaml.Visibility.Collapsed;
}
public event SelectionChangedEventHandler SelectionChanged;
private void ForumList_SelectionChanged( object sender,SelectionChangedEventArgs e)
{
SelectionChanged(sender,e);
}