BringIntoView nicht

Question

Arbeit habe ich diesen Code hinter Ereignishandler:

private void comboActiveStudentAssignmentType_SelectionChanged(object sender, SelectionChangedEventArgs e) 
{ 
    List<Border> borders = new List<Border>(); 

    // The list of border (focus rectangles) matches the combo of assignment types 
    borders.Add(borderBibleReadingMain); 
    borders.Add(borderBibleReadingClass1); 
    borders.Add(borderBibleReadingClass2); 
    borders.Add(borderMainHallStudent1); 
    borders.Add(borderMainHallAssistant1); 
    borders.Add(borderMainHallStudent2); 
    borders.Add(borderMainHallAssistant2); 
    borders.Add(borderMainHallStudent3); 
    borders.Add(borderMainHallAssistant3); 
    borders.Add(borderClass1Student1); 
    borders.Add(borderClass1Assistant1); 
    borders.Add(borderClass1Student2); 
    borders.Add(borderClass1Assistant2); 
    borders.Add(borderClass1Student3); 
    borders.Add(borderClass1Assistant3); 
    borders.Add(borderClass2Student1); 
    borders.Add(borderClass2Assistant1); 
    borders.Add(borderClass2Student2); 
    borders.Add(borderClass2Assistant2); 
    borders.Add(borderClass2Student3); 
    borders.Add(borderClass2Assistant3); 

    // Loop through the borders 
    for(int iBorder = 0; iBorder < borders.Count; iBorder++) 
    { 
     // Is this border the active student assignment? 
     if (comboActiveStudentAssignmentType.SelectedIndex == iBorder) 
     { 
      // Yes, so use a red brush for the background 
      borders[iBorder].BorderBrush = Brushes.Red; 

      // Now we must ensure the correct tab item is visible 
      if(iBorder >= 0 && iBorder <= 2) 
      { 
       expandTFGW.IsExpanded = true; 

       if (iBorder == 0) 
        tabTFGWReadingMainHall.IsSelected = true; 
       else if (iBorder == 1) 
        tabTFGWReadingClass1.IsSelected = true; 
       else if (iBorder == 2) 
        tabTFGWReadingClass2.IsSelected = true; 
      } 
      else if (iBorder >= 3 && iBorder <= 8) 
      { 
       expandAYFM.IsExpanded = true; 
       tabAYFMStudentsMainHall.IsSelected = true; 

       if (iBorder == 3 || iBorder == 4) 
        tabMainHallItem1.IsSelected = true; 
       else if (iBorder == 5 || iBorder == 6) 
        tabMainHallItem2.IsSelected = true; 
       else if (iBorder == 7 || iBorder == 8) 
        tabMainHallItem3.IsSelected = true; 
      } 
      else if (iBorder >= 9 && iBorder <= 14) 
      { 
       expandAYFM.IsExpanded = true; 
       tabAYFMStudentsClass1.IsSelected = true; 

       if (iBorder == 9 || iBorder == 10) 
        tabClass1Item1.IsSelected = true; 
       else if (iBorder == 11 || iBorder == 12) 
        tabClass1Item2.IsSelected = true; 
       else if (iBorder == 13 || iBorder == 14) 
        tabClass1Item3.IsSelected = true; 
      } 
      else if (iBorder >= 15) 
      { 
       expandAYFM.IsExpanded = true; 
       tabAYFMStudentsClass2.IsSelected = true; 

       if (iBorder == 15 || iBorder == 16) 
        tabClass2Item1.IsSelected = true; 
       else if (iBorder == 17 || iBorder == 18) 
        tabClass2Item2.IsSelected = true; 
       else if (iBorder == 19 || iBorder == 20) 
        tabClass2Item3.IsSelected = true; 
      } 

      borders[iBorder].BringIntoView(); 
     } 
     else 
     { 
      // No, so set the background to transparent so we can't see it. 
      borders[iBorder].BorderBrush = Brushes.Transparent; 
     } 
    } 
} 

}

Ein Beispiel für eine der Border Objekte in XAML:

<Border x:Uid="borderMainHallStudent1" x:Name="borderMainHallStudent1" BorderThickness="5"> 
    <Border.Style> 
     <Style x:Uid="Style_30" TargetType="Border"> 
      <Setter x:Uid="Setter_76" Property="BorderBrush" Value="Transparent"/> 
      <Style.Triggers> 
       <DataTrigger x:Uid="DataTrigger_29" Binding="{Binding SelectedItem, ElementName=comboActiveStudentAssignmentType}" 
         Value="{x:Static StudentInfoEnums:StudentAssignmentType.Student1Main}"> 
        <Setter x:Uid="Setter_77" Property="BorderBrush" Value="Red"/> 
       </DataTrigger> 
      </Style.Triggers> 
     </Style> 
    </Border.Style> 
    <StackPanel x:Uid="StackPanel_35"> 
     <Label x:Uid="Label_38" Content="Student:"/> 
     <Grid x:Uid="Grid_15"> 
      <Grid.ColumnDefinitions> 
       <ColumnDefinition x:Uid="ColumnDefinition_34" Width="*"/> 
       <ColumnDefinition x:Uid="ColumnDefinition_35" Width="auto"/> 
      </Grid.ColumnDefinitions> 
      <TextBox x:Uid="textMainHallStudent1" x:Name="textMainHallStudent1" 
       Text="{Binding MainHallStudent1, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" 
       IsEnabled="False" Grid.Column="0" Margin="2" /> 
      <Button x:Uid="buttonMainHallStudent1" x:Name="buttonMainHallStudent1" Grid.Column="1" Background="Transparent" 
       DataContext="{Binding DataContext, ElementName=oclmEditor}" 
       Command="{Binding ApplicationCommand}" 
       CommandParameter="Student1Main"> 
       <Image x:Uid="Image_17" Source="Images/AssignmentTypeStudent16.png" Margin="2"/> 
      </Button> 
     </Grid> 
     <Label x:Uid="Label_39" Content="Study:"/> 
     <ComboBox x:Uid="ComboBox_9" DataContext="{Binding DataContext, ElementName=oclmEditor}" 
       ItemsSource="{Binding StudentStudyPointsList}" 
       ItemContainerStyle="{StaticResource StudyPointComboBoxStyle}" 
       ItemTemplate="{StaticResource StudyPointComboItem}" 
       Validation.ErrorTemplate="{StaticResource StudyPointValidationTemplate}" 
       Tag="{Binding Meeting.MainHallStudent1, Mode=OneWay, UpdateSourceTrigger=PropertyChanged}" 
       SelectedValue="{Binding Meeting.MainHallStudent1StudyNumber, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" 
       SelectedValuePath="Number"/> 
    </StackPanel> 
</Border> 

Diese Codezeile: borders[iBorder].BringIntoView(); Es scheint nicht zu funktionieren. Die Farben aller meiner Border-Objekte sind richtig eingestellt, aber das Programm macht offensichtlich keinen Versuch, diese Codezeile zu widerlegen.

Um Ihnen den Kontext, wo dieses Border Objekt vorhanden ist:

\\ Main Window 
    \\ScrollView 
     \\ Expander 
      \\Tab Control 
      \\Tab Item 
       \\Border 1 
        \\Contents 
       \\Border 2 
        \\Contents 
     \\ Expander 
      \\Tab Control 
      \\Tab Item 
       \\Border 1 
        \\Contents 
       \\Border 2 
        \\Contents 

Answer 1

BringIntoView() nach MSDN:

Versuche, dieses Element in den Blick zu bringen, in irgendwelchen scrollbaren Regionen es ist in enthalten.

Daher werden keine Registerkartenelemente ausgewählt, Expander erweitert usw. Sie müssen das selbst tun.

Beachten Sie, dass der Inhalt aufgrund der Prioritätswarteschlange des Dispatchers möglicherweise nicht verfügbar ist, sobald Sie Änderungen vornehmen (z. B. eine Registerkarte auswählen). In diesem Fall können Sie die Bring-in-View-Anfrage in einer niedrigeren Priorität stellen:

var localBorderIndex = iBorder; // copy to avoid closure of loop variable 
Dispatcher.InvokeAsync(() => borders[localBorderIndex].BringIntoView(), 
    DispatcherPriority.Background);