无法从listview WPF中的选定项目获取值

Question

我有一个表单,用户输入有关新库存项目(ID,标题,价格,日期等)的数据.输入的数据将保存到集合中,然后在列表视图中重新显示.

我得到一个"指定的强制转换无效",指向"key =(int)lvwInventory.SelectedItems [0];" 在尝试提取所选值时.我正在尝试获取ID并使用它打开该项目的编辑窗口.

我在这做错了什么？

列出有问题的视图

<ListView Height="249" HorizontalAlignment="Left" Margin="27,28,0,0" Name="lvwInventory" VerticalAlignment="Top" Width="384" ItemsSource="{Binding col}">
    <ListView.View>
        <GridView>
            <GridViewColumn Header="Type" DisplayMemberBinding="{Binding Type}" />
            <GridViewColumn Header="Title" DisplayMemberBinding="{Binding Title}" />
            <GridViewColumn Header="Price" DisplayMemberBinding="{Binding Price}" />
            <GridViewColumn Header="Date Added" DisplayMemberBinding="{Binding Date}" />
        </GridView>
    </ListView.View>
</ListView>

stockobject类

public class StockObject
    {
        // create stock object properties
        public int ID { get; set; }
        public string Title { get; set; }
        public DateTime Date { get; set; }
        public double Price { get; set; }
        public char Type { get; set; }

试图从所选项目中获取价值的事件

private void btnViewItem_Click(object sender, RoutedEventArgs e)
    {
        int key;

        if (lvwInventory.SelectedIndex == -1) return;

        key = (int)lvwInventory.SelectedItems[0];

        StockObject s = col[key];
        bookDialog.View(s);
    }

Answer 1

所选项目是StockObject本身,这就是为什么它不允许你将它转换为int.你需要这样的东西:

var selectedStockObject = lvwInventory.SelectedItems[0] as StockObject;
if(selectedStockObject == null)
{
   return;
}

key = selectedStockObject.ID; //I'm assuming you want the ID as your key