可能有幾種方法可以做到這一點，這裏是另外一個。我修改了UserControl，以便在頁面大小更改和/或收藏更改時自動調整項目大小以將其顯示爲方格。
的用戶控件XAML代碼：
<UserControl
x:Class="MyControls.MyUserControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:MyControls"
Name="myControl">
<GridView Background="{ThemeResource ApplicationPageBackgroundThemeBrush}" ItemsSource="{Binding ElementName=myControl, Path=Items}"
Width="{Binding ElementName=myControl, Path=CurrentWidth}" HorizontalAlignment="Center"
Height="{Binding Width, RelativeSource={RelativeSource Self}}">
<GridView.ItemContainerStyle>
<Style TargetType="GridViewItem">
<Setter Property="Margin" Value="0"/>
</Style>
</GridView.ItemContainerStyle>
<GridView.ItemTemplate>
<DataTemplate>
<Border Padding="10" Width="{Binding ElementName=myControl, Path=ElementSize}" Height="{Binding ElementName=Width, RelativeSource={RelativeSource Self}}">
<Border BorderBrush="Red" BorderThickness="3">
<Image Source="ms-appx:///Assets/StoreLogo.png" Stretch="UniformToFill"/>
</Border>
</Border>
</DataTemplate>
</GridView.ItemTemplate>
</GridView>
</UserControl>
用戶控件後面的代碼：
public sealed partial class MyUserControl : UserControl, INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private void RaiseProperty(string name) => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));
public IList Items
{
get { return (IList)GetValue(ItemsProperty); }
set { SetValue(ItemsProperty, value); }
}
public static readonly DependencyProperty ItemsProperty =
DependencyProperty.Register("Items", typeof(IList), typeof(MyUserControl),
new PropertyMetadata(0, (s, e) =>
{
if (Math.Sqrt((e.NewValue as IList).Count) % 1 != 0)
Debug.WriteLine("Bad Collection");
}));
public void Items_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
if (Math.Sqrt(Items.Count) % 1 != 0) Debug.WriteLine("Bad Collection");
RaiseProperty(nameof(ElementSize));
}
private double currentWidth;
public double CurrentWidth
{
get { return currentWidth; }
set { currentWidth = value; RaiseProperty(nameof(CurrentWidth)); RaiseProperty(nameof(ElementSize)); }
}
public double ElementSize => (int)(currentWidth/(int)Math.Sqrt(Items.Count)) - 1;
public MyUserControl()
{
this.InitializeComponent();
}
}
的XAML的MainPage：
<Grid>
<local:MyUserControl x:Name="myControl" Items="{Binding MyItems}"/>
<Button Content="Add" Click="Button_Click"/>
</Grid>
代碼的MainPage背後：
public sealed partial class MainPage : Page
{
private ObservableCollection<int> myItems = new ObservableCollection<int> { 1, 2, 3, 4, 5, 6, 7, 8 };
public ObservableCollection<int> MyItems
{
get { return myItems; }
set { myItems = value; }
}
public MainPage()
{
this.InitializeComponent();
DataContext = this;
MyItems.CollectionChanged += myControl.Items_CollectionChanged;
}
protected override Size MeasureOverride(Size availableSize)
{
myControl.CurrentWidth = Math.Min(availableSize.Height, availableSize.Width);
return base.MeasureOverride(availableSize);
}
private void Button_Click(object sender, RoutedEventArgs e) => MyItems.Add(3);
}
該程序以「壞集合」開頭 - 有8個項目，因此您無法從中創建方形網格，但只要您單擊提供的按鈕 - 集合的計數將更改爲9，網格應該更新本身。
你能編譯這段代碼嗎？ – tgpdyk
是的，否則我將無法發佈圖片。 – fsp
我明白了。在.NET 4.5中，ItemTemplate不是GridView的一部分。無論如何，我看到你的標籤是UWP，所以它可能在那裏工作。 – tgpdyk