c# - 从字符串到 guid 的转换无效 - 如何解决此问题？

Question

有谁知道我为什么会得到这个？我不是一个 ASP.NET 人员，所以试图为某人修复一些东西。

Exception Details: System.InvalidCastException: Invalid cast from 'System.String' to 'System.Guid'.

Source Error:

Line 135:        {
Line 136:            dataSet = new DataSet();
Line 137:            adapter.Fill(dataSet);
Line 138:        }
Line 139:        finally

完整的 C#

public DataSet pendingCourses()
    {
        DataSet dataSet = new DataSet();
        User user = (User)Context.Items["CurrentUser"];

        SqlConnection selectConnection = new SqlConnection(ConfigurationSettings.AppSettings["DBConnectStr"]);
        SqlDataAdapter adapter = new SqlDataAdapter("dbo.procUsersGetInProgressCourses", selectConnection);
        adapter.SelectCommand.CommandType = CommandType.StoredProcedure;

        // get results
        adapter.SelectCommand.Parameters.Add("@Limit", SqlDbType.Int).Value = 5;
        adapter.SelectCommand.Parameters.Add("@Culture", SqlDbType.VarChar, 6).Value = "en-GB";
        adapter.SelectCommand.Parameters.Add("@UserID", SqlDbType.UniqueIdentifier).Value = "EC9D439A-A084-48A4-80DD-80F7BB00AEF2";

        try
        {
            dataSet = new DataSet();
            adapter.Fill(dataSet);
        }
        finally
        {
            if (selectConnection.State == ConnectionState.Open)
            {
                selectConnection.Close();
            }
        }
        return dataSet;
    }

Answer 1

你可以尝试:

 .Value = new Guid("EC9D439A-A084-48A4-80DD-80F7BB00AEF2");

SqlDbType.UniqueIdentifier对应的.NET类型是 System.Guid，因此您需要为其指定一个 Guid 类型的值。