绑定到GridView.Items.Count在UWP中始终返回0

Question

I have a gridview in UWP and work fine

 <GridView x:Name="my_gridview" ItemsSource="{Binding CollectionItem, Mode=TwoWay}"/>

And have a textblock for show the count of CollectionItem

 <TextBlock Text="{Binding ElementName=my_gridview, Path=Items.Count, RelativeSource={RelativeSource Self}}"/>

Problem: the textblock always show 0 even we have many items in my gridview!

Answer 1

更好地直接绑定到源集合：

<TextBlock Text="{Binding CollectionItem.Count}" />

Answer 2

您同时设置ElementName和RelativeSource （这是伪造的），后者可能会覆盖前者或导致冲突错误，请检查“输出”窗口，然后将出现绑定错误。