c# - “无法将类型系统 web ui webcontrols listitem”转换为我的班级

Question

我正在尝试从 a 中获取一个项目listbox并将其作为一个car项目。

我想取出tempcar，取出它的值并将它们添加到会话状态值中，我可以在其中编辑不同页面上的值。

目前我正在使用来自应用程序的这个回收代码，但由于以下问题，它似乎不适用于 webforms cannot convert type system web ui webcontrols listitem to car

  if (lbxCars.SelectedItem != null)
  {
      car tempCar = lbxCars.SelectedItem as car;    
  }

任何帮助将不胜感激。我也知道我在做的是笨重的，但它是为了展示功能。

谢谢

    public partial class _Default : System.Web.UI.Page
{
    private static AmazonDynamoDBClient client = new AmazonDynamoDBClient();
    private static string tableName = "CarTable";
    private static string car_1 = "05-Rn-1964";
    private static string car_2 = "05-Rn-1965";
    private static string car_3 = "05-Rn-1966";
    List<car> cars = new List<car>();
protected void Page_Load(object sender, EventArgs e)
{



    Amazon.DynamoDBv2.DocumentModel.Table CarTable = Amazon.DynamoDBv2.DocumentModel.Table.LoadTable(client, tableName);
    GetItemOperationConfig config = new GetItemOperationConfig
    {
        AttributesToGet = new List<string> { "Reg", "Manufactor", "Year", "Problems" },
        ConsistentRead = true
    };
    Document doc1 = CarTable.GetItem(car_1, config);
    Document doc2 = CarTable.GetItem(car_2, config);
    Document doc3 = CarTable.GetItem(car_3, config);

    string Reg1 = doc1["Reg"].AsString();
    string Manufactor1 = doc1["Manufactor"].AsString();
    string Year1 = doc1["Year"].AsString();
    string Problems1 = doc1["Problems"].AsString();

    string Reg2 = doc2["Reg"].AsString();
    string Manufactor2 = doc2["Manufactor"].AsString();
    string Year2 = doc2["Year"].AsString();
    string Problems2 = doc2["Problems"].AsString();

    string Reg3 = doc3["Reg"].AsString();
    string Manufactor3 = doc3["Manufactor"].AsString();
    string Year3 = doc3["Year"].AsString();
    string Problems3 = doc3["Problems"].AsString();




    car car1 = new car(Reg1, Manufactor1, Year1, Problems1);
    car car2 = new car(Reg2, Manufactor2, Year2, Problems2);
    car car3 = new car(Reg3, Manufactor3, Year3, Problems3);
    cars.Add(car1);
    cars.Add(car2);
    cars.Add(car3);







    lbxCars.DataSource = cars;
    lbxCars.DataBind();

}

protected void LinkButton1_Click(object sender, EventArgs e)
{
    Server.Transfer("Default.aspx", true);
}

protected void LinkButton2_Click(object sender, EventArgs e)
{
    Server.Transfer("EditCar.aspx", true);
}

protected void LinkButton3_Click(object sender, EventArgs e)
{
    Server.Transfer("NewCar.aspx", true);
}

protected void LinkButton4_Click(object sender, EventArgs e)
{
    Server.Transfer("ViewDataBase.aspx", true);
}

protected void Button2_Click(object sender, EventArgs e)
{
    Server.Transfer("EditCar.aspx", true);
}

protected void ListBox1_SelectedIndexChanged(object sender, EventArgs e)
{
    if (lbxCars.SelectedItem != null)
    {
        //car tempCar = lbxCars.SelectedItem as car;

    }
}

}

标签： c#webforms

Answer 1

您可以尝试这样的事情，其中​​ ID 是您用于列表框中的 SelectedValue 的属性。

protected void ListBox1_SelectedIndexChanged(object sender, EventArgs e)
{
    if (lbxCars.SelectedValue != null)
    {
        var tempCar = cars.Any(e=>e.ID==lbxCars.SelectedValue );
    }
}