从var项中获取值？

Question

我有wp8应用程序，列表选择器绑定到xml数据源，当我选择项目我希望能够获得“源”src位置文件位置我有这个功能当我检查项目我发现src选择了名称

private void SoudListPicker_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e)
{
    // TODO: Add event handler implementation here.

    var item  = (sender as ListPicker).SelectedItem;
    MessageBox.Show("Selected Item is : " + item);
}

Answer 1

var使用赋值语句右侧的结果类型来推断它的类型，在这种情况下（我相信）是object。

要使属性可见，您需要将SelectedItem强制转换为实际类型。

private void SoudListPicker_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e)
{
    // TODO: Add event handler implementation here.

    var item  = ((sender as ListPicker).SelectedItem) as Expression.Blend.SampleData.soundsEFXSampleDataSource3.sound;

    if(item != null)
        MessageBox.Show("Selected Item is : " + item.src);
}