当切换到加载数据的数据透视表项时,我在从一项切换到另一项时遇到卡顿现象。我已将数据加载分离到一个单独的线程中,这很有帮助,但我仍然遇到一些糟糕的性能....想知道你们是否有任何想法....
这是枢轴项
<Grid x:Name="LayoutRoot" Background="Transparent">
<!--Pivot control-->
<controls:Pivot Name="panCorals" Title="Corals" Foreground="#01487e"
SelectionChanged="panCorals_SelectionChanged">
<controls:Pivot.Background>
<ImageBrush ImageSource="PivotBackground.png"/>
</controls:Pivot.Background>
<!--Search Corals-->
<controls:PivotItem Header="Search" Foreground="#01487e">
<Grid>
<toolkit:PerformanceProgressBar Name="SearchCoralsProgressBar" HorizontalAlignment="Left"
VerticalAlignment="Top" Width="466"
IsEnabled="{Binding IsSearchLoading}" IsIndeterminate="{Binding IsSearchLoading}" />
<StackPanel>
<TextBox Name="txtSearchTerm" KeyDown="txtSearchTerm_KeyDown" />
<ListBox Name="lbSearchCorals" Margin="0,0,-12,0" ItemsSource="{Binding SearchCorals}"
SelectionChanged="lbSearchCorals_SelectionChanged">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" Margin="0,0,0,17">
<Image Source="{Binding MainImageURI}" Height="100" Width="100" Margin="12,0,9,0" />
<StackPanel Width="311">
<TextBlock Text="{Binding CommonName}" Foreground="#112d42" TextWrapping="NoWrap" Style="{StaticResource PhoneTextTitle2Style}"/>
<TextBlock Text="{Binding ScientificName}" Foreground="#112d42" TextWrapping="Wrap" Margin="12,-6,12,0" Style="{StaticResource PhoneTextSubtleStyle}"/>
</StackPanel>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</StackPanel>
</Grid>
</controls:PivotItem>
<!--Top Corals-->
<controls:PivotItem Header="Top" Foreground="#01487e" VerticalAlignment="Top" >
<Grid>
<toolkit:PerformanceProgressBar Name="TopCoralsProgressBar" HorizontalAlignment="Left"
VerticalAlignment="Top" Width="466"
IsEnabled="{Binding IsTopLoading}" IsIndeterminate="{Binding IsTopLoading}" />
<ListBox Name="lbTopCorals" Margin="0,0,-12,0" ItemsSource="{Binding TopCorals}" SelectionChanged="lbTopCorals_SelectionChanged">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" Margin="0,0,0,17">
<Image Source="{Binding MainImageURI}" Height="100" Width="100" Margin="12,0,9,0" />
<StackPanel Width="311">
<TextBlock Text="{Binding CommonName}" Foreground="#112d42" TextWrapping="NoWrap" Style="{StaticResource PhoneTextTitle2Style}"/>
<TextBlock Text="{Binding ScientificName}" Foreground="#112d42" TextWrapping="Wrap" Margin="12,-6,12,0" Style="{StaticResource PhoneTextSubtleStyle}"/>
</StackPanel>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
<StackPanel Margin="10,50,0,0" Orientation="Horizontal">
<TextBlock x:Name="tbProgress"/>
</StackPanel>
</Grid>
</controls:PivotItem>
<!--New Corals-->
<controls:PivotItem Header="New">
<Grid>
<toolkit:PerformanceProgressBar Name="NewCoralsProgressBar" HorizontalAlignment="Left"
VerticalAlignment="Top" Width="466"
IsEnabled="{Binding IsNewLoading}" IsIndeterminate="{Binding IsNewLoading}" />
<ListBox Name="lbNewCorals" Margin="0,0,-12,0" ItemsSource="{Binding NewCorals}" SelectionChanged="lbNewCorals_SelectionChanged">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" Margin="0,0,0,17">
<Image Source="{Binding MainImageURI}" Height="100" Width="100" Margin="12,0,9,0" />
<StackPanel Width="311">
<TextBlock Text="{Binding CommonName}" Foreground="#112d42" TextWrapping="NoWrap" Style="{StaticResource PhoneTextTitle2Style}"/>
<TextBlock Text="{Binding ScientificName}" Foreground="#112d42" TextWrapping="Wrap" Margin="12,-6,12,0" Style="{StaticResource PhoneTextSubtleStyle}"/>
</StackPanel>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
</controls:PivotItem>
</controls:Pivot>
</Grid>
以及背后的代码......
private void panCorals_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
switch (panCorals.SelectedIndex)
{
case 0: //search corals
break;
case 1: //top corals
if (!App.vmCoral.IsTopDataLoaded)
{
App.vmCoral.IsTopLoading = true;
if (App.HasConnectivity)
{
//get corals from web
bw.DoWork += new DoWorkEventHandler(bw_DoWorkTopCoralsWeb);
if (bw.IsBusy != true)
{
bw.RunWorkerAsync();
}
}
else
{
//get saved corals from device
bw.DoWork += new DoWorkEventHandler(bw_DoWorkTopCoralsSaved);
if (bw.IsBusy != true)
{
bw.RunWorkerAsync();
}
}
}
break;
case 2: //new corals
if (!App.vmCoral.IsNewDataLoaded)
{
App.vmCoral.IsNewLoading = true;
if (App.HasConnectivity)
{
//get corals from web
bw.DoWork += new DoWorkEventHandler(bw_DoWorkNewCoralsWeb);
if (bw.IsBusy != true)
{
bw.RunWorkerAsync();
}
}
else
{
//get saved corals from device
bw.DoWork += new DoWorkEventHandler(bw_DoWorkNewCoralsSaved);
if (bw.IsBusy != true)
{
bw.RunWorkerAsync();
}
}
}
break;
default:
break;
}
}
最佳答案
您发布的代码本身并没有什么特别的问题。最有可能发生的情况是,当您在数据透视项之间切换时,您的后台工作线程正在完成,这反过来会更新您的列表绑定(bind)到的可观察集合。此外,您的列表包含图像,如果您绑定(bind)到需要下载图像的 Web URL,也会导致性能问题。
有几件事需要检查:
- 如果您的列表很长,请确保您正在使用虚拟堆栈面板(这是默认设置,但请确保您没有在任何地方更改它)。
- 考虑使用 SL 工具包中的 LongListSelector 控件,它比默认的 ListBox 具有更好的 UI 和数据虚拟化支持
- 如果您要将图像绑定(bind)到网址 (http://blogs.msdn.com/b/delay/archive/2010/09/02/keep-a-low-profile-lowprofileimageloader-helps-the-windows-phone-7-ui-thread-stay-responsive-by-loading-images-in-the-background.aspx),请检查低调图像加载器。
- 在您的 App.xaml.cs 中启用“EnableRedrawRegions”调试指示器。检查在切换枢轴项目时是否没有任何内容导致区域被重绘(由屏幕的一部分快速闪烁不同的颜色表示)。如果是,请考虑使用 BitMapCache。
- 如果您的异步进程正在下载一个长列表,请考虑在后台线程中分解该列表,并仅将它们以小块的形式分派(dispatch)到 UI 线程,每个 block 之间的延迟很小。
关于c# - Windows Phone 7 如何在枢轴项之间切换时删除 "stuttering",我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/6932170/