我试图在C＃中使用实体框架将对象添加到SQL数据库。数据来自文本框和日期选择器控件的组合。我猜测这是我解析数据时遇到的问题，但是错误对我来说似乎很模糊。任何建议将不胜感激。

这是将数据添加到数据库的代码。

private void new_btn_Click(object sender,RoutedEventArgs e)
{
        var load = new Load
        {
            pro_num = pro_txt.Text,quote_num = quote_txt.Text,ref_num = ref_txt.Text,weight = Convert.ToDouble(weight_txt.Text),pieces = Convert.ToInt32(pieces_txt.Text),commodity = commodity_txt.Text,mileage = Convert.ToDouble(mileage_txt.Text),carrier_rate = Convert.ToDecimal(carrierRate_txt.Text),customer_rate = Convert.ToDecimal(customerRate_txt.Text),pick_appointment = pickDate_picker.SelectedDate,drop_appointment = dropDate_picker.SelectedDate,driver_id = Convert.ToInt32(driver_txt),dispatch_id = Convert.ToInt32(dispatch_txt),customer_id = Convert.ToInt32(customer_txt),broker_id = Convert.ToInt32(broker_txt),};

        Hotloadmodel.Loads.Add(load);
        Hotloadmodel.SaveChangesAsync();
}

以下是EF实体类的代码：

public partial class Load
{
    public int bol_num { get; set; }
    public string pro_num { get; set; }
    public string quote_num { get; set; }
    public string ref_num { get; set; }
    public Nullable<double> weight { get; set; }
    public Nullable<int> pieces { get; set; }
    public string commodity { get; set; }
    public Nullable<double> mileage { get; set; }
    public Nullable<decimal> carrier_rate { get; set; }
    public Nullable<decimal> customer_rate { get; set; }
    public Nullable<System.DateTime> pick_appointment { get; set; }
    public Nullable<System.DateTime> drop_appointment { get; set; }
    public Nullable<int> driver_id { get; set; }
    public Nullable<int> dispatch_id { get; set; }
    public Nullable<int> customer_id { get; set; }
    public Nullable<int> broker_id { get; set; }
}

这是我的数据库表的架构。

CREATE TABLE [dbo].[Loads] 
(
    [bol_num]          INT IDENTITY (1,1) NOT NULL,[pro_num]          VARCHAR(20)  NULL,[quote_num]        VARCHAR(20)  NULL,[ref_num]          VARCHAR(20)  NULL,[weight]           FLOAT(53)    NULL,[pieces]           INT          NULL,[commodity]        VARCHAR(20)  NULL,[mileage]          FLOAT(53)    NULL,[carrier_rate]     MONEY        NULL,[customer_rate]    MONEY        NULL,[pick_appointment] SMALLDATETIME NULL,[drop_appointment] SMALLDATETIME NULL,[driver_id]        INT           NULL,[dispatch_id]      INT           NULL,[customer_id]      INT           NULL,[broker_id]        INT           NULL,PRIMARY KEY CLUSTERED ([bol_num] ASC)
);