CODEWITHSUNDEEP
windows-phone-7
BillyMadisonnn
BillyMadisonnn

Reputation: 35

When I Add many Items into ListBox, I get OutOfMemoryException . How to modify it?

this is my ListBox:

XMLA:

<Style x:Key="ListBoxStyle" TargetType="ListBox">
        <Setter Property="Foreground" Value="{StaticResource PhoneForegroundBrush}"/>
        <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Disabled"/>
        <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="ListBox">
                    <ScrollViewer x:Name="ScrollViewer">
                        <Grid>
                            <Grid.RowDefinitions>
                                <RowDefinition Height="{TemplateBinding Height}"/>
                                <RowDefinition Height="100"/>
                            </Grid.RowDefinitions>
                            <ItemsPresenter Grid.Row="0"/>
                            <Button Content="Add" Grid.Row="1" Click="Button_Click"/>
                        </Grid>
                    </ScrollViewer>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>  <ListBox Style="{StaticResource ListBoxStyle}" Name="listBox" Height="600" ItemsSource="{Binding MyData}">
                <ListBox.ItemTemplate>
                    <DataTemplate>
                        <StackPanel>
                            <TextBlock Text="{Binding Name}"/>
                            <Image Source="{Binding Img}" Stretch="UniformToFill"/>
                        </StackPanel>
                    </DataTemplate>
                </ListBox.ItemTemplate>
            </ListBox>

Code-Behind:

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        for (int i = 0; i < 50; i++)
        {
            MyData.Add(new Data { Name = i.ToString(), Img = "/Background.png" });
        }
    }

When I Click Button more, I get a OutOfMemoryException.

but,If I don't set ListBox Style. I add Items into ListBox,the Project is Work.

Upvotes: 0

Views: 503

Answers (2)

notacat
notacat

Reputation: 691

I suppose, to enable virtualization you should change ListBox ControlTemplate. Move all except of ItemsPresenter out of ScrollViewer:

<ControlTemplate TargetType="ListBox">
  <Grid>
     <Grid.RowDefinitions>
        <RowDefinition />
        <RowDefinition Height="100"/>
     </Grid.RowDefinitions>
     <ScrollViewer x:Name="ScrollViewer" Grid.Row="0">
          <ItemsPresenter />
     </ScrollViewer>
     <Button Content="Add" Grid.Row="1" Click="Button_Click"/>
  </Grid>
</ControlTemplate>

And make sure that your MyData implements IList interface.

Upvotes: 0

Ku6opr
Ku6opr

Reputation: 8126

When you retemplate the ListBox, you lose data virtualization. So, all your item images are in memory all the time. Can you decrease the size of the images to avoid high memory consumption?

Upvotes: 1

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