Windows 8 series-GirdView rolling event acquisition-casual

XAML:

  <GridView       x:Name="itemGridView"  >            <GridView.ItemsPanel>                <ItemsPanelTemplate>                    <VirtualizingStackPanel Orientation="Horizontal"/>                </ItemsPanelTemplate>            </GridView.ItemsPanel>            <GridView.GroupStyle>                <GroupStyle>                    <GroupStyle.HeaderTemplate>                        <DataTemplate>                            <Grid Margin="1,0,0,6">                                <Button                                    AutomationProperties.Name="Group Title"                                    Click="Header_Click"                                    Style="{StaticResource TextPrimaryButtonStyle}" >                                    <StackPanel Orientation="Horizontal">                                        <TextBlock Text="{Binding Title}" Margin="3,-7,10,10" Style="{StaticResource GroupHeaderTextStyle}" />                                        <TextBlock Text="{StaticResource ChevronGlyph}" FontFamily="Segoe UI Symbol" Margin="0,-7,0,10" Style="{StaticResource GroupHeaderTextStyle}"/>                                    </StackPanel>                                </Button>                            </Grid>                        </DataTemplate>                    </GroupStyle.HeaderTemplate>                    <GroupStyle.Panel>                        <ItemsPanelTemplate>                                                      <VariableSizedWrapGrid Orientation="Vertical" Margin="0,0,80,0"/>                                                  </ItemsPanelTemplate>                    </GroupStyle.Panel>                                    </GroupStyle>            </GridView.GroupStyle>        </GridView>

. Cs:

/// <Summary> /// locate the control content control by name /// </summary> /// <typeparam name = "T"> </typeparam> // /<param name = "parent"> </param> // <param name = "name"> </param> // <returns> </returns> public T findVisualChildByName <T> (DependencyObject parent, string name) where T: DependencyObject {for (int I = 0; I <VisualTreeHelper. getChildrenCount (parent); I ++) {var child = VisualTreeHelper. getChild (parent, I); string ControlName = child. getValue (Control. nameProperty) as string; if (controlName = name) {return child as T;} else {T result = FindVisualChildByName <T> (child, name); if (result! = Null) return result;} return null ;}

XAML-. cs:

// Locate the scrollViewer and scrollBar registration value change event in the gridview // The Tip obtains the event and registers it only after the bound data is obtained. Otherwise, the scrollviewer var scrollViewer = this is not obtained. findVisualChildByName <ScrollViewer> (this. itemGridView, "ScrollViewer ");
// Find the Horizontal Rolling axis var scroollBar = this. FindVisualChildByName <ScrollBar> (scrollViewer, "HorizontalScrollBar"); scroollBar. ValueChanged + = scroollBar_ValueChanged;

Private void scroollBar_ValueChanged (object sender, RangeBaseValueChangedEventArgs e) {ScrollBar scrollbar = sender as ScrollBar; // when the scroll bar value is the maximum and if (e. newValue = scrollbar. maximum &&! IsLoading) {// load data LoadData () asynchronously; // set the value offset of the roller to start the valueChanged event scrollbar again. value = e. newValue-1E-8;} if (e. newValue = scrollbar. minimum ){}}