异常类型的则“”，无法转换类型“MS.Internal.NamedObject”在前端为类型“System.Data.DataRowView”

Question

代码的对象：

<ListView Name="lvCus" MouseDoubleClick="ListViewItem_DoubleClick"> 
    <ListView.View> 
     <GridView AllowsColumnReorder="true" ColumnHeaderToolTip="TbCus"> 
      <GridViewColumn Header="CusID" Width="40" DisplayMemberBinding="{Binding Path=CusID}" /> 
      <GridViewColumn Header="Firstname" Width="120" DisplayMemberBinding="{Binding Path=fn}" /> 
      <GridViewColumn Header="Lastname" Width="120" DisplayMemberBinding="{Binding Path=ln}" /> 
      <GridViewColumn Header="Dob" Width="100" DisplayMemberBinding="{Binding Path=dob}" /> 
      <GridViewColumn Header="Age" Width="60" DisplayMemberBinding="{Binding Path=age}" /> 
     </GridView> 
    </ListView.View> 
</ListView> 

下面是代码在后端：

private void ListViewItem_DoubleClick(object sender, RoutedEventArgs e) 
{ 
    System.Data.DataRowView cusObj = (System.Data.DataRowView)lvCus.SelectedItem; 
    var myobj = cusObj.Row.ItemArray; 
    txtCusID.Text = myobj[0].ToString();  
    txtfn.Text = myobj[1].ToString(); 
    txtln.Text = myobj[2].ToString(); 
    txtdob.Text = myobj[3].ToString(); 
    txtage.Text = myobj[4].ToString(); 
} 

ListView加载数据，它似乎有一个空行在最后。当我点击ListView的空行时，出现以下错误：

A first chance exception of type 'System.InvalidCastException' occurred in WpfApp.exe

Additional information: Unable to cast object of type 'MS.Internal.NamedObject' to type 'System.Data.DataRowView'.

If there is a handler for this exception, the program may be safely continued.

我得到了上面的错误，我该如何解决这个问题？伙计们，我正处于学习阶段。

Answer 1

您应该使用的运营商，以确保SelectedItem属性实际上为了避免得到一个异常返回System.Data.DataRowView当上排在用户双击：

private void ListViewItem_DoubleClick(object sender, RoutedEventArgs e) 
    { 
     System.Data.DataRowView cusObj = lvCus.SelectedItem as System.Data.DataRowView; 
     if (cusObj != null) 
     { 
      var myobj = cusObj.Row.ItemArray; 
      txtCusID.Text = myobj[0].ToString(); 
      txtfn.Text = myobj[1].ToString(); 
      txtln.Text = myobj[2].ToString(); 
      txtdob.Text = myobj[3].ToString(); 
      txtage.Text = myobj[4].ToString(); 
     } 
    }