列表框：WP8上的内存不足异常

Question

I have two ListBoxs in my pivot and each has an image.

<DataTemplate x:Key="PostsFieldItemTemplate" >
    ...
      <Image  Grid.Row="0" Margin="5" Width="100" Height="100" HorizontalAlignment="Left" Source="{Binding WImage}" Stretch="UniformToFill"/>
    ...
</DataTemplate> 

<DataTemplate x:Key="ItemTemplateListBoxAnimation">
    ...
    <Image Width="235" Height="210" Grid.Row="0" Source="{Binding tImage}" Stretch="UniformToFill"/>
    ...
</DataTemplate>

And i add url string to image in my code

PostsField.Items.Add(new ListPost(post.id, api.improveText(post.title), api.improveText(post.excerpt), post.attachments[0].url, api.improveDate(post.date)));

GridImages.Items.Add(new TempGrid(post.id, post.attachments[0].url, api.improveText(post.title), api.improveDate(post.date)));

Then i press on my button "LOAD MORE" and at some point I recieve exception (Out Of Memory). I commented out <Image Source="{Binding MyImage}"... /> in my ItemTemplates and all is ok..

Can you tell me please, what should i do to improve my Images ?

Answer 1

there is a limit on memory usage for app here is the details. you can find detail here

as you mentioned that you are loading images form API(web API I think). and showing them in list box on some button click and at some point out of memory exception is thrown. now on low memory phone, an app can use upto 150MB of phone memory. when your app exceeds that limit it throws this exception is thrown. what you can do is to remove/dispose previously added images from listbox to release the memory and than add new Images.

You can check the memory limit available to your app by checking the ApplicationWorkingSetLimit value using the DeviceExtendedProperties.GetValue(String) method. For an example of how to do this see How to disable features in apps for lower-memory phones for Windows Phone 8

Hope this helps