Question

在这种情况下，如何绑定到收集项目？

//Both collections have OnPropertyChanged("");
public ObservableCollection<Grid> ConnectorsGrids { get; set; }
public ObservableCollection<double> Connectors { get; set; }

//Coordinates collection
Connectors = new ObservableCollection<double>() { 10 , A - 20 };

ConnectorsGrids = new ObservableCollection<Grid>();

foreach (var e in Connectors)
{
    ConnectorsGrids.Add(DrawConnector(new Thickness(e * YB1, 0, 0, 0)));
}

YB1是元素大小的系数。它是可变的，取决于屏幕的大小

YB1不在任何集合中。是类中的参数

DrawConnector()将边距作为参数

我希望页边距根据屏幕尺寸而改变

目前，它会计算输出值，然后在更改屏幕大小时，更改仍会保留

Answer 1

您可以尝试以下方法：

xaml：

<ItemsControl x:Name="PART_ItemsControl"
          ItemsSource="{Binding Connectors}">
   <ItemsControl.ItemTemplate>
        <DataTemplate>
            <ContentControl Content="{Binding Converter={local:ToGridConverter}"/>
        </DataTemplate>
    </ItemsControl.ItemTemplate>
</ItemsControl>

转换器：

sealed class ToGridConverter : MarkupExtension, IValueConverter{
   public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
    if (value is double)
    {
       double e = (double)value;
       return DrawConnector(new Thickness(e * YB1, 0, 0, 0));
    }            
    return Binding.DoNothing;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
    throw new NotImplementedException();
}

private ToGridConverter _converter;
public override object ProvideValue(IServiceProvider serviceProvider)
{
    if (_converter == null)
    {
        _converter = new ToGridConverter ();
    }
    return _converter;
}}

绑定到ObservableCollection中的元素

1 个答案: